Wet. Dry have issues due to heat management and failing seals that end up slathering the clutch in lubricants. It boggles my mind that an engineer would choose dry. I think the idea was to reduce costs. In Ford's case it resulted in a fairly nasty class action law suit.
Wet clutch has the problem of friction material building up in the fluid, which can cause wear and deteriorate the other components. Dry clutch is more modular, the clutch is more self-contained and seems like it would be better for long-term serviceability: if the clutch wears out, you can just replace that part.
Hm thanks for reminding me that I need to change the fluid in my DSG.
It's annoying that the VW manual suggests comically long service intervals for this stuff to make it look like the running costs are lower than they are. I want to just keep the car until it has 300k+ miles. But it's all about shifting those units initially.
Concentric-shaft wet DCTs aren't bad - for example, replacing the clutch pack on a VW DQ250 is very similar to replacing the torque converter on an automatic. You have to drain it but it's not particularly involved. There's basically a cover on the bell housing behind the flywheel, drain the fluid, remove the snap ring, and you're looking at the clutch pack. Lift it off and lift a new one back on.
Rebuilding the clutch packs themselves is a tedious and obnoxious process, because they're a giant stack of friction material that needs to be shimmed into tolerance, but you often just buy the clutch pack as a whole assembly.
I'd massively prefer a wet clutch even for long term serviceability - a few hundred dollars or less every year or two for fresh fluid and you've got a long service life before an expensive removal.
In my experience wet clutches in automatics far outlasted any dry clutch that I was aware of. Toyotas last a long time but your bog standard iffy Ford AOD clutches would easily last beyond 200k abused. There are many clutch rings packed together and engagement is precise. Fluid changes are fairly easy...or can be. Ford has recently removed the dipsticks on their amazing 6speed truck transmission making it very difficult to change.
The diversity in today's transmissions is finally bringing in a golden age... except for manual transmission fans (though still the most economical option, automatics have grossly improved with all of these new technologies).
* Hybrids are largely "Power Split Devices" (Toyota / Ford / etc. etc.) which use a planetary gearset to kinda-sorta make a CVT-like approach.
* CVTs with belts and/or cones are all available, to varying qualities.
* Dry DCTs have created sub-100ms shifts in automatic transmissions
* ZF8 (wet-clutch planetary gear / torque-converter traditional automatic) has sub 200ms shifts (~150ms or so for the typical ZF-8). Just old tech but done exceptionally well today.
Agree on pure IC ones. Hybrid ones, like the one on the Prius, while still technically a CVT, are nothing like the jatco crap Nissan and others had been putting on IC cars. They are quite reliable.
The "eCVT" in the Toyota hybrid system isn't a CVT at all, but rather a system that uses the electric motors with planetary gearsets to keep the engine operating as close to its optimal RPM as possible: https://youtu.be/O61WihMRdjM?si=hPoLm8EZnbiLH60h
I think it was Honda who tried out a 2 motor planetary gear setup to eliminate the transmission and I don't know why it was abandoned because it was brilliant.
The idea was that you need a certain velocity and torque to hold the drive train at a given speed, and instead of using reconfigurable gearsets for that, you use a differential, and one of the output shafts is sometimes an input shaft. One of the output shafts is attached to the wheels, the other to a motor. At some speeds output shaft B is stationary. To accelerate, you feed power into the motor and now it's speeding up shaft A. At lower speeds, you bleed power off of shaft B by running the motor as a dynamo, using it to charge the batteries and run auxiliary equipment.
In the hybrid version there was an ICE on the input shaft (or an ICE and a ganged electric motor) but on a full electric you could run two motors with different torque curves and balance the inputs for each speed.
Toyota is the manufacturer famous for their 2-motor planetary setup (they call it Hybrid Synergy Drive), and they've licensed it to a couple of other manufacturers, like Ford and Nissan.
Honda's old system, 'IMA', which was a traditional ICE drivetrain with a motor assist. They abandoned it because mild hybrids don't really deliver a good value. It's a lot more cost for not very much improvement in economy.
Honda's new system, E-drive, usually operates like an EV with a generator attached, but it also has a lock-up clutch to allow the engine to direct drive the wheels in cruising conditions.
2x Electric Motors + 1x ICE motor. Its a bit confusing but there's a lot of Youtube demos, webpage-demos, and simulations to help you understand how it all works.
The 10R80 in the F-150 has known problems, while the ZF8 is one of the best transmissions currently made. It's also used in BMWs, the Toyota Supra, and the new Ineos Grenadier. Having driven it, my only issue was that it was slow to switch from deceleration/engine braking mode to acceleration mode. That programming allows it to feel more like a manual when you let off the gas, but it takes a good fraction of a second to switch between them.
I love driving my manual, although I recognize in this day and age that is probably kind of silly on my part. Are the new automatic transmissions really as much an improvement in fuel efficiency as the manufacturers claim? I'd like to justify buying another manual, but I can't ignore a 4 mpg gain in fuel efficiency.
I think the reason automatic is more efficient is you'll often get more gears, maybe like 12, so it stays closer to the most efficient RPM. And it'll shift way up just cause you let off the gas for a second, so engine-braking is minimal. Stickshift drivers can maaybe do that, probably not. I can see those two things saving 4 MPG. Also have no idea if the EPA tests account for average stickshift driving habits.
I've had a couple of hybrids and I've always been able to hit the EPA numbers as long as I'm not driving in the mountains. And on state highways I can usually beat them. Some of the numbers hybrids are putting down are damn good these days. The base Camry hybrid starts under $30K and gets >50mpg.
if you use fuel consumption instead fuel economy to look at it the differences can be small. I have both auto and manual transmission vehicles, and for me personally, I almost always beat the rated consumption numbers in manual and rarely beat it in the auto. This just boils down to how I drive; I end up going much slower when driving manual (in a small Ford Ranger pickup) than I do in either auto.
I love driving my manual too and would like to beg you to keep buying them -- the few of us that still appreciate them are the only shred of remaining market
I was shocked at the gearing of my friend's stickshift 5-gear Nissan Versa. The revs are so high at freeway speeds in 5th. Doesn't get very good highway MPG.
I wonder if that's an artifact of it being a parts-bin transmission meant for countries with slower highway speeds. Nissans larger cars in the US are North America specific models.
Automatic transmissions also have gears and no one is designing a bespoke unit to install on a mass produced car, also because the same car has many trims levels with different weights and different engines.
Dry Clutch DCT technology is nearly equivalent efficiency to a manual transmission. Its the same dry-clutch to connect the engine to the wheels after all, though there's additional weight required as Gear1/3/5/7 are on Clutch#1 and Gear2/4/6/8 are on Clutch#2.
ZF-8 apparently removed a lot of the "slushbox" / wet-clutch problems with efficiency. Its apparently the best / peak automatic transmission technology with exceptionally good reviews and specifications, though the main problem seems to be downshifts. But upshifts (1->2->3->4...) are basically solved with ZF-8 and operate at high efficiency.
CVTs are manual-transmission/clutch-like levels of efficiency, though there's so much diversity in CVT implementations I feel like its hard to discuss.
Hybrid Vehicles are either directly-connected / 1-gear systems (ex: Honda: ICE Engine gets a gear and EV engine gets a 2nd gear, no transmission otherwise required), or the Toyota Power-split device (aka: Prius) that has exceptionally good efficiency as you're probably aware.
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Manual Transmission's main benefit is economy. Its just a bit of hydraulics controlling a drum-brake like system (aka: the Clutch) with a human controlling the gears, so no need for any complex logic.
I think economy cars / low-cost cars need to go back to manual transmissions. But maybe USA is just too rich and that the $20,000+ price point is high enough to just default to automatic transmissions.
There's a lot of "machine empathy" in manual transmissions, they're exceptionally simple, cheap, and reliable (when used properly).
I'll only own manual cars. On a long highway ride and consciously want to conserve fuel, I often get better mileage (+3-4 mpg) than my car is rated. If I'm low on fuel I can drive in a way that will eak out extra miles just by keeping it in high gear, driving at the lowest RPMs possible for the terrain, coasting long distances in neutral...
My car is a dual-clutch automatic. On a long highway ride, where I'm doing nothing special besides just driving at a steady speed or using cruise control, I'll often get +6 or more MPG over my car's highway rating.
I got my dual clutch in 2010 and have barely felt guilty about not driving stick since then. Particularly because in Volkswagen's rendition of DCT, the car will react to riding the brake by using engine braking. There are certain hill shapes where it doesn't really work, but it works nearly perfectly on shallow inclines. Light tap at the top and it will hold speed the entire way down.
People will often point out that you can use the override but I feel like that misses the point. There's what a person can do, and what they will do, and when we are talking about something like global fuel economy and carbon emissions, 'will do' is the only metric that actually matters. And hybrid electrics and DCTs fare better in the 'will do' category.
I wish more people knew how the power-split devices in modern hybrids worked. The 'eCVT' and similar terminology they often get just doesn't do it justice. They're a beautiful design, and entirely different than 'CVTs' as most people know them.
Some of new hybrids remove transmission altogether - Honda and Nisan use ICE as a generator and wheels are powered by electrical motor.
Honda hybrids also have a clutch to connect gas engine directly to the wheels on motorway speeds to improve efficiency. And it simulates sound of gear changes during acceleration even if there are no gears whatsoever, since that's apparently what makes it more exciting and enjoyable to us petrolheads:
It’s a lot of extra weight to carry around and extra systems that can break and need maintenance. Especially tricky since they’re only expected to be used sparingly.
Toyota's Power Split Device seems like a superior design to me.
1. Change the engine to Atkinson Engine. This makes low-end torque terrible.
2. Make up for low-end torque by paring a small 80 horsepower electric motor (which handles 0rpm exceptionally well). Atkinson Engine does 2000+ rpm / highway speeds exceptionally well. Use a computer + a 3rd electric motor to configure the planetary gears to make the EV motor #1 and ICE engine cooperate best.
3. Beef up the alternator into a proper generator (to charge the battery when its low). Use the motors to hold the car still if stopped at a stop-light but keep the ICE engine on the generator to build up the charge you need to take off later.
4. Use the EV motor as the starter (hook it up to the engine to start it up, much like a traditional starter).
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As such: the Power Split Device removes the alternator, starter, and traditional transmission (with the EV motor#1 and EV motor#2 + computer allowing different configurations / rotations to recreate alternator / starter / transmission-like behaviors).
With... here's the big magic... the ICE + EV Motor being able to assist each other on the highway. (Honda's ICE as Generator approach leads to 100% ICE on the highways). Toyota Prius has a better ability to mix EV vs ICE (even the ability to run 100% EV at the push of a button, though at dramatically worse performance since IIRC its only a sub-100hp electric motor).
> (Honda's ICE as Generator approach leads to 100% ICE on the highways).
Well, it's 100% when load is between zero and a reasonable maximum torque at the fixed gear ratio. If you lift, the engine shuts off, and if you command significant acceleration, the engine will revert back to generator duties.
Honda's system has an advantage on the highway too -- because no motor ever spins faster than the output drive motor, there is no speed ceiling at which the engine must run to prevent either MGs from overspinning. You can take a Honda hybrid to the speed limiter, lift the throttle, and it will go into EV mode immediately. This is nice in areas where you might end up coasting a lot on the highway because you can get some time with the engine off, even at highway speeds.
> And it simulates sound of gear changes during acceleration even if there are no gears whatsoever, since that's apparently what makes it more exciting and enjoyable to us petrolheads:
Only the gearheads who don't understand torque and efficiency curves! I hate that Honda made this change on their latest generation of Hybrids. It is an intentional performance compromise made just to satisfy the expectations of an uninformed buyer. RPM fluctuation under acceleration is a drawback of fixed gear ratio transmissions, not an advantage.
Nissan CVTs do this (or did, I guess they're phasing CVTs out) apparently in response to driver complaints. Seems most felt it disconcerting that it just stayed at one RPM, even if it is more efficient and performant.
I'm not sure it's ICE rpms that are fluctuating, these could be artificial gear-shifting engine sounds through car stereo. At least I read comments that new Civic does that, didn't have a chance to drive new Honda hybrids myself.
I used to love driving a manual transmission, but if you live in a city you have to be a masochist to use them. I drove a six speed on a 30-40 minute commute on the 101 in LA for just a few months and started developing knee pain from constantly using the clutch.
I found the clutch was easier once I started finding the average speed of traffic and did that instead of changing speed to keep up. Those large gaps were safer too.
I was thinking about people who squeeze in when you're already at min safe following distance. But also, no it doesn't always help the flow of traffic to follow as close as possible.
I don't know what it's like in the states, but if you do that here in the UK then some idiot will jump into the gap in a bid to try and get a couple of car-lengths ahead and then you're forced to brake anyway.
Once a road hits a certain density of vehicles, the only way to fit more vehicles on the road is to close the gaps between the vehicles.
One cannot realistically expect urban regions to have drivers that leave large spaces of road empty, it wouldn’t back up the congestion even further onto other roads.
It’s especially exacerbated because all vehicles and drivers have different reaction times and acceleration, so it’s inevitable that gaps will increase and decrease. Taking advantage of the gaps actually increases the road’s throughput, and is a sufficient tradeoff to risk and energy efficiency for almost all drivers worldwide.
Depends on the type of traffic. You're describing gridlock, but temporary jams are more common on freeways. In those situations, if everyone left extra following space, it'd actually improve the overall throughput since people take extra time to stop then start. In some places, the police or automatic signs will even tell people to slow down in advance when there's a jam ahead.
> Once a road hits a certain density of vehicles, the only way to fit more vehicles on the road is to close the gaps between the vehicles.
Even better is to get the cars off the road by having good flow and not jamming it up.
"Closing the gaps" means tailgating or switching lanes to get into those sweet, wide open spaces. These are the primary causes of phantom traffic jams on congested freeways. There's a pretty good deep dive covering this[1].
>Even better is to get the cars off the road by having good flow and not jamming it up.
This is not practical in most cases of congestion, which are caused by the number of vehicles exceeding the road's capacity. There is no other choice after a certain point, vehicles will begin to pile up and speed up and slow down creating the traffic waves.
That video is correct for only a minority of times where the road capacity has not been met, but people are accelerating and decelerating too fast causing the traffic waves.
However, during times of too many vehicles on the road, such as rush hour, there is nothing anyone can do, other than use as much of the road as possible (i.e. less empty space).
> However, during times of too many vehicles on the road, such as rush hour, there is nothing anyone can do, other than use as much of the road as possible (i.e. less empty space).
Your analysis misses safety and so while your facts are correct your conclusion is wrong. When more cars want to use a section of road than the road can handle you must not put more cars into the empty space without all the cars slowing down (which in turn means the road can handle less cars per time). I know that is not what everyone does, but they (we) are wrong.
I intended for “risk” to be short for “safety risk” in the below portion of my original comment:
> Taking advantage of the gaps actually increases the road’s throughput, and is a sufficient tradeoff to risk and energy efficiency for almost all drivers worldwide.
> the road can handle you must not put more cars into the empty space without all the cars slowing down (which in turn means the road can handle less cars per time)
I agree that there is a range where cars weaving in and out causing people to brake unnecessarily causes more congestion, but there is also a point where there is so much congestion that “filling in the gaps” becomes the optimal move, because the road’s capacity has been reached and maintaining large gaps would simply push congestion further back onto other roads.
The problem is that there is no filling in of gaps without lane changes that cause the congestion. Everyone is making what they perceive to be the optimal move for them: "I'll just change over to that lane, because there's open space there and this one's going slow," but that individually optimal strategy isn't optimal for the movement of traffic as a group.
You don't even need to maintain large gaps - you just need about two seconds of time between you and the car in front of you, and that varies based on the speed of traffic. Everyone going ~30mph with gaps is going to have a lot more throughput than everyone averaging 10mph with short gaps. Of course this is before you get into the increased risk of collisions with smaller gaps. One fender bender is enough to bring everything to a halt, and statistically with enough cars and short enough gaps those are basically guaranteed.
Yeah, try setting your nav from Los Angeles to Irvine or San Diego to Irvine on any given day. Guaranteed 2-3 wrecks, plus some jams that the nav might think are wrecks but are just phantom jams.
How hard are you pressing the clutch that it gives you knee pain?
I did my first 10 years of driving in a manual and when you get a hang of the gearbox you barely need the clutch at all. Just a light tap, barely disengage anything.
Nowadays the sequential dogbox in my motorcycle is my fav. Similar to what rally cars use. You only need the clutch when stopping, otherwise you can just jam between gears with a light flick of the throttle to relieve tension. No electronics.
Wish nonracing cars came with that option. I think some 90’s supercars have it.
> if you live in a city you have to be a masochist to use them
I think in the mountains it’s the opposite. I wouldn’t want to drive 1km of elevation down without using the engine to control the speed. Brakes in most cars aren’t designed to engage continuously for long time, they overheat and may eventually fail.
Also, many newer cars will automatically downshift if they think you want to engine-brake. Usually based on the fact that your foot is off the gas and on the brake for a long period of time.
I totally acknowledge that automatics are now technically superior in most ways. But I just cannot stand the robot between me and what I want the car to do. When I am stuck in a snowbank and want to rock the car, or am about to pass a tuck on a mountain highway, or want to engine brake down a long hill, I don't want an unpredictable machine trying to decide when and if to shift. I would buy an automatic that would never shift unless told so to do, but such things are not available on consumer cars.
Automatics are also just one more unfixable thing to go wrong. An automatic has so many moving parts, most of which are tiny little things buried deep inside. Manuals just run forever, needing at most new clutch plates or slave cylinders, things external to the actual transmission. Fixing anything to do with an automatic is akin to automotive heart surgery.
VW/Audi DCT has manual mode that allows shift up/down and stays set on a gear. The only difference is it won’t comply if you aggressively downshift or will eventually shift up if you rev too much.
Ya, I don't want to get into an argument with my car. I want a transmission that will actively allow the engine to stall, or let the rev limiter do its thing. I also want a clutch that I control, one that will engage when I ask it rather than a second later, which is a bigger deal in snow/mud/rock. A couple weeks ago I had to rock my car out of some deep snow (snowed-in parking spot). An automatic just will not engage/disengage fast enough on command for such trickery.
Which is exactly the problem. If I'm pushing my car to redline, it's because I want the car there. Maybe I'm trying to climb a questionably legal driveway, maybe I'm trying to smoke some Beamer off a stoplight to impress a date. I made the jump over to full electric after my 90's Integra got stolen, and damn do I miss that car sometimes.
don't forget the part where EVs are making transmissions themselves obsolete. there are still underlying gears, but there's just not a transmission in the same way.
Ish. I think EVs in the long term will use two gears.
1-gear transmission seems... ill-suited. Its only possible on grossly-overpowered EVs (ex: Tesla). Economical cars like Leaf would likely benefit from a 2nd speed.
Honda Accord Hybrids have a silly design: EV Motor is permanently on low-gear, while ICE-engine is permanently on high-gear. You could call it a two-gear system, but perhaps its two motors each permanently attached to a single gear without any traditional "transmission" (aka: system to change gears). Just a computer that is deciding to take more (or less) power to the ICE vs EV.
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EVs are well known to have poor highway cruising economy. I do wonder if a 2nd gear would help them out.
Hahaha yes a friend of mine that had an affected Fiesta used that term liberally. Not unrelated, he got rid of the thing and never bought another Ford product again.
Too few people these days understand the delicious sensation you get when coming round a bend, dropping the clutch, shifting gears, and feeling the whoosh of power that results from a mechanical interaction between your body and a machine.
I agree with traditional slushbox automatics. You don't get that distinct gear shift feeling, so it's boring. But DCT seems closer to the manual feeling. Cannot confirm since I've never driven one, but it felt that way as a passenger.
I say the same thing about Electric Cars. Being able to effortlessly press someone back into their seat on a open empty road while hearing the whine of the electric motors is incredibly fun, so much more so that manual cars.
Mashing the throttle takes literally zero skill, hitting a proper heel-toe will always be more satisfying to me as it has taken years for me to perfect and I still mess up here and there.
Plus, a tuned Golf R/STI/Evo can throw people in their seats effortlessly too, and rolling antilag will always sound cool.
For those lamenting the loss of manual transmissions in cars, have you tried motorcycling? Motorcycling: for when you want to beat a Lambo on a $19k motorcycle in a quarter mile race :)
But seriously, they are a great second vehicle to have, or even main vehicle depending on where you live. They are simpler than cars and you can work on them using basic hand tools easily enough. They are cheap and good on gas. And they are just really really fun.
FYSA, manuals can come in wet and dry clutch arrangements. Most manual cars/trucks use dry clutches outside the transmission but most modern motorcycles use a "wet" clutch with the entire transmission/clutch bathed in the engine oil. Doing so saves weight/complexity and keeps everything more rigid. This is also why you can smell a burning clutch plate on a car but not on a motorcycle. But if you ever hear a Ducati motorcycle that sounds odd at idle, sounding like it is broken, that sound may be because Ducati is one of the few major brands that used external "dry" clutches.
105 comments
[ 3.2 ms ] story [ 177 ms ] threadIt's annoying that the VW manual suggests comically long service intervals for this stuff to make it look like the running costs are lower than they are. I want to just keep the car until it has 300k+ miles. But it's all about shifting those units initially.
Rebuilding the clutch packs themselves is a tedious and obnoxious process, because they're a giant stack of friction material that needs to be shimmed into tolerance, but you often just buy the clutch pack as a whole assembly.
I'd massively prefer a wet clutch even for long term serviceability - a few hundred dollars or less every year or two for fresh fluid and you've got a long service life before an expensive removal.
* Hybrids are largely "Power Split Devices" (Toyota / Ford / etc. etc.) which use a planetary gearset to kinda-sorta make a CVT-like approach.
* CVTs with belts and/or cones are all available, to varying qualities.
* Dry DCTs have created sub-100ms shifts in automatic transmissions
* ZF8 (wet-clutch planetary gear / torque-converter traditional automatic) has sub 200ms shifts (~150ms or so for the typical ZF-8). Just old tech but done exceptionally well today.
Dig the ZF8 in my RAM a lot. Did not like the 10 speed in my F-150, ZF is much better.
The idea was that you need a certain velocity and torque to hold the drive train at a given speed, and instead of using reconfigurable gearsets for that, you use a differential, and one of the output shafts is sometimes an input shaft. One of the output shafts is attached to the wheels, the other to a motor. At some speeds output shaft B is stationary. To accelerate, you feed power into the motor and now it's speeding up shaft A. At lower speeds, you bleed power off of shaft B by running the motor as a dynamo, using it to charge the batteries and run auxiliary equipment.
In the hybrid version there was an ICE on the input shaft (or an ICE and a ganged electric motor) but on a full electric you could run two motors with different torque curves and balance the inputs for each speed.
Honda's old system, 'IMA', which was a traditional ICE drivetrain with a motor assist. They abandoned it because mild hybrids don't really deliver a good value. It's a lot more cost for not very much improvement in economy.
Honda's new system, E-drive, usually operates like an EV with a generator attached, but it also has a lock-up clutch to allow the engine to direct drive the wheels in cruising conditions.
3-motor actually. https://eahart.com/prius/psd/
2x Electric Motors + 1x ICE motor. Its a bit confusing but there's a lot of Youtube demos, webpage-demos, and simulations to help you understand how it all works.
And all that is without considering hybrid tech.
ZF-8 apparently removed a lot of the "slushbox" / wet-clutch problems with efficiency. Its apparently the best / peak automatic transmission technology with exceptionally good reviews and specifications, though the main problem seems to be downshifts. But upshifts (1->2->3->4...) are basically solved with ZF-8 and operate at high efficiency.
CVTs are manual-transmission/clutch-like levels of efficiency, though there's so much diversity in CVT implementations I feel like its hard to discuss.
Hybrid Vehicles are either directly-connected / 1-gear systems (ex: Honda: ICE Engine gets a gear and EV engine gets a 2nd gear, no transmission otherwise required), or the Toyota Power-split device (aka: Prius) that has exceptionally good efficiency as you're probably aware.
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Manual Transmission's main benefit is economy. Its just a bit of hydraulics controlling a drum-brake like system (aka: the Clutch) with a human controlling the gears, so no need for any complex logic.
I think economy cars / low-cost cars need to go back to manual transmissions. But maybe USA is just too rich and that the $20,000+ price point is high enough to just default to automatic transmissions.
There's a lot of "machine empathy" in manual transmissions, they're exceptionally simple, cheap, and reliable (when used properly).
People will often point out that you can use the override but I feel like that misses the point. There's what a person can do, and what they will do, and when we are talking about something like global fuel economy and carbon emissions, 'will do' is the only metric that actually matters. And hybrid electrics and DCTs fare better in the 'will do' category.
Some of these designs are mind-blowingly simple. My favorite is Honda's E-drive: https://www.youtube.com/watch?v=QLUIExAnNcE
Honda hybrids also have a clutch to connect gas engine directly to the wheels on motorway speeds to improve efficiency. And it simulates sound of gear changes during acceleration even if there are no gears whatsoever, since that's apparently what makes it more exciting and enjoyable to us petrolheads:
https://www.youtube.com/watch?v=1JbpJR4frGY
In some ways I'm surprised that more EVs don't have this as an option:
* https://en.wikipedia.org/wiki/Range_extender
Batteries keep going down in price and weight
1. Change the engine to Atkinson Engine. This makes low-end torque terrible.
2. Make up for low-end torque by paring a small 80 horsepower electric motor (which handles 0rpm exceptionally well). Atkinson Engine does 2000+ rpm / highway speeds exceptionally well. Use a computer + a 3rd electric motor to configure the planetary gears to make the EV motor #1 and ICE engine cooperate best.
3. Beef up the alternator into a proper generator (to charge the battery when its low). Use the motors to hold the car still if stopped at a stop-light but keep the ICE engine on the generator to build up the charge you need to take off later.
4. Use the EV motor as the starter (hook it up to the engine to start it up, much like a traditional starter).
--------
As such: the Power Split Device removes the alternator, starter, and traditional transmission (with the EV motor#1 and EV motor#2 + computer allowing different configurations / rotations to recreate alternator / starter / transmission-like behaviors).
With... here's the big magic... the ICE + EV Motor being able to assist each other on the highway. (Honda's ICE as Generator approach leads to 100% ICE on the highways). Toyota Prius has a better ability to mix EV vs ICE (even the ability to run 100% EV at the push of a button, though at dramatically worse performance since IIRC its only a sub-100hp electric motor).
Well, it's 100% when load is between zero and a reasonable maximum torque at the fixed gear ratio. If you lift, the engine shuts off, and if you command significant acceleration, the engine will revert back to generator duties.
Honda's system has an advantage on the highway too -- because no motor ever spins faster than the output drive motor, there is no speed ceiling at which the engine must run to prevent either MGs from overspinning. You can take a Honda hybrid to the speed limiter, lift the throttle, and it will go into EV mode immediately. This is nice in areas where you might end up coasting a lot on the highway because you can get some time with the engine off, even at highway speeds.
Only the gearheads who don't understand torque and efficiency curves! I hate that Honda made this change on their latest generation of Hybrids. It is an intentional performance compromise made just to satisfy the expectations of an uninformed buyer. RPM fluctuation under acceleration is a drawback of fixed gear ratio transmissions, not an advantage.
The artificial audio is also a thing, but if they only did it with that, you'd also hear the engine droning a constant pitch in the background.
Also notice how the 'power' meter is dropping (accurately) from 100% each time.
I wish Honda made a Civic Type R with a DCT.
One cannot realistically expect urban regions to have drivers that leave large spaces of road empty, it wouldn’t back up the congestion even further onto other roads.
It’s especially exacerbated because all vehicles and drivers have different reaction times and acceleration, so it’s inevitable that gaps will increase and decrease. Taking advantage of the gaps actually increases the road’s throughput, and is a sufficient tradeoff to risk and energy efficiency for almost all drivers worldwide.
Read the above as a rant for better transit.
Even better is to get the cars off the road by having good flow and not jamming it up.
"Closing the gaps" means tailgating or switching lanes to get into those sweet, wide open spaces. These are the primary causes of phantom traffic jams on congested freeways. There's a pretty good deep dive covering this[1].
[1] https://www.autoblog.com/2022/11/03/phantom-traffic-jams-pre...
This is not practical in most cases of congestion, which are caused by the number of vehicles exceeding the road's capacity. There is no other choice after a certain point, vehicles will begin to pile up and speed up and slow down creating the traffic waves.
That video is correct for only a minority of times where the road capacity has not been met, but people are accelerating and decelerating too fast causing the traffic waves.
However, during times of too many vehicles on the road, such as rush hour, there is nothing anyone can do, other than use as much of the road as possible (i.e. less empty space).
Your analysis misses safety and so while your facts are correct your conclusion is wrong. When more cars want to use a section of road than the road can handle you must not put more cars into the empty space without all the cars slowing down (which in turn means the road can handle less cars per time). I know that is not what everyone does, but they (we) are wrong.
> Taking advantage of the gaps actually increases the road’s throughput, and is a sufficient tradeoff to risk and energy efficiency for almost all drivers worldwide.
> the road can handle you must not put more cars into the empty space without all the cars slowing down (which in turn means the road can handle less cars per time)
I agree that there is a range where cars weaving in and out causing people to brake unnecessarily causes more congestion, but there is also a point where there is so much congestion that “filling in the gaps” becomes the optimal move, because the road’s capacity has been reached and maintaining large gaps would simply push congestion further back onto other roads.
You don't even need to maintain large gaps - you just need about two seconds of time between you and the car in front of you, and that varies based on the speed of traffic. Everyone going ~30mph with gaps is going to have a lot more throughput than everyone averaging 10mph with short gaps. Of course this is before you get into the increased risk of collisions with smaller gaps. One fender bender is enough to bring everything to a halt, and statistically with enough cars and short enough gaps those are basically guaranteed.
I did my first 10 years of driving in a manual and when you get a hang of the gearbox you barely need the clutch at all. Just a light tap, barely disengage anything.
Nowadays the sequential dogbox in my motorcycle is my fav. Similar to what rally cars use. You only need the clutch when stopping, otherwise you can just jam between gears with a light flick of the throttle to relieve tension. No electronics.
Wish nonracing cars came with that option. I think some 90’s supercars have it.
I think in the mountains it’s the opposite. I wouldn’t want to drive 1km of elevation down without using the engine to control the speed. Brakes in most cars aren’t designed to engage continuously for long time, they overheat and may eventually fail.
Automatics are also just one more unfixable thing to go wrong. An automatic has so many moving parts, most of which are tiny little things buried deep inside. Manuals just run forever, needing at most new clutch plates or slave cylinders, things external to the actual transmission. Fixing anything to do with an automatic is akin to automotive heart surgery.
DCTs will absolutely give you this experience. Most don't expose a UI for shifting from directly to any gear arbitrarily, though.
Ya, I don't want to get into an argument with my car. I want a transmission that will actively allow the engine to stall, or let the rev limiter do its thing. I also want a clutch that I control, one that will engage when I ask it rather than a second later, which is a bigger deal in snow/mud/rock. A couple weeks ago I had to rock my car out of some deep snow (snowed-in parking spot). An automatic just will not engage/disengage fast enough on command for such trickery.
1-gear transmission seems... ill-suited. Its only possible on grossly-overpowered EVs (ex: Tesla). Economical cars like Leaf would likely benefit from a 2nd speed.
Honda Accord Hybrids have a silly design: EV Motor is permanently on low-gear, while ICE-engine is permanently on high-gear. You could call it a two-gear system, but perhaps its two motors each permanently attached to a single gear without any traditional "transmission" (aka: system to change gears). Just a computer that is deciding to take more (or less) power to the ICE vs EV.
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EVs are well known to have poor highway cruising economy. I do wonder if a 2nd gear would help them out.
Plus, a tuned Golf R/STI/Evo can throw people in their seats effortlessly too, and rolling antilag will always sound cool.
Made for a fun time of getting nowhere pretty quickly.
But seriously, they are a great second vehicle to have, or even main vehicle depending on where you live. They are simpler than cars and you can work on them using basic hand tools easily enough. They are cheap and good on gas. And they are just really really fun.