in the wild Inline 6 (I6) engines have proved reliable and just going on regular maintenance
B58 (BMW) is super reliable & high performance
same as the I6 used in certain landcruisers & other Toyota cars etc
though now of course - with super cheap solar etc - if you can go electric go electric but if you've to buy an ICE car - yeah buy an I6 - fuel efficient & performance & reliable
From Toyota there are many greats: 1FZ-FE, 1HZ, 1HD-FT, 12H-T, etc
The Cummins 5.9L is excellent, particularly the 12 valve with P7100 pump. Awesome low end torque.
From Mercedes the M104 and OM606 are phenomenal. Powerful, efficient, incredibly reliable. The only drawback is the aging engine management software is not very well supported by aftermarket code readers anymore. In the case of an OM606 you can fix this by deleting the ECU entirely and installing an M pump from an OM603, or replacing the ECU with a DSL-1 standalone unit.
I had an '89 Cherokee to 235k and sold it for ~60% of my purchse price after 6 years after garages only quoted insanity for the smallest things (Dad is a mechanic, but the commute there for repairs isn't feasible on the regular and apartment living is not conducive to the required garage/tools).
Dad has seen AMC I-6s go 400k before the transmission died and ended its run.
Europe has stupid displacement taxes so they'll make some high strung 0.9L turbo 3/4cyl with all the technology that gets .01mpg better MPG than a ~2L engine while taking twice as much $$ in service to make it to any given milage.
IDK why they don't just tax the actual fuel used like the rest of the world (not that they don't do that).
Even in the US, I4 engines are by far the most popular. Most consumer cars are built for fuel economy with the one notable exception being the suburban tacticool pickup truck, which are often modded to burn MORE fuel.
It does not hurt that you can easily get 200+ horsepower from the factory with one, either. My car is a series hybrid with an Atkinson-cycle I4 but it still bursts to 200hp because it's a hybrid.
I have a Mazda CX-9 with an I4 and, my anecdote, it sucks on gas. About 14 mpg in non-highway short hop driving. That might be fine as part of larger group but it always feels embarrassingly low.
The inline four has largely converged around a 2.0L displacement with an equal bore and stroke. IIRC, it's fairly optimal from a performance and thermodynamic efficiency standpoint.
Seems weird. The I6 has a few packaging issues that made them unpopular in the 1980s when front drive vehicles became the standard.
Australia was awash in I6 motors, from the GM Holden motors, the Ford Falcon engine and the Chrysler slant 6 that got replaced by a locally developed version of a Chrysler 6 that was never finished by the US corp. they were all boring, mostly durable, mostly reliable engines for a family car.
Even BMC/Leyland had one. Uniquely they fitted it across the chassis of a land crab derived vehicle which showed why the I6 was ill suited to being packaged as anything other than in line with a rear drive drivetrain.
The V6 fits better in front drive cars for obvious reasons.
Hybrid cars change the equation somewhat, the skateboard chassis doesn’t seem all that suited to an I6 but here we are.
Chrysler have unfortunately found out that no matter how good you make one, customers still want a V8 and I concur.
Ah, the old Chrysler slant 6. I had friends who would buy used beater cars as long as they had these engines. They never seemed to die. Everything would be broken, but that engine always started.
The logical, socially-conscious side of my brain can't wait to see 6 cylinder engines go the way of the v8. Four cylinders and a hybrid system ought to be able to generate enough torque for just about anyone (except maybe heavy-duty hauling?). And the future is of course BEV.
But have to admit there is a part of me that would really love to drive something like the BMW M340i [1]. And the gas mileage (26/33 MPG) isn't even too bad.
It is awesome. Incredible power. Silky smooth on highway. Sounds like a beast on start up. I regularly get 36/37 mpg on a long drive.
I prefer the sound of the B58 in the m340 over the S58 in the m3 but they are quite different engines. And way different power. But straight-six throughout.
Still think one of the best engine sounds out there is the s54 in the 2001-2006 m3
Nope. As I said, you can build two engines with different bore and stroke, but the same displacement, and they will make mirror images in the power curve.
If it was such and advantage, wouldn't all performance engines have much longer stroke?
The newest Corvette ZR1 makes 1064hp from a 4.1 inch bore and 3.1 stroke. How much power are they leaving on the table by not making it a larger stroke than bore like many inline 6's? (Hint: inline sixes don't have larger stroke than bore for "torque")
Any change in power from a larger stroke is due to the larger displacement. It goes up with a percentage of the increase. Nothing to do with the leverage of the longer stroke.
By the way if you work the math out on that, it's not significant. And there are many other things that go into the losses of and engine turning. It's such a useless micro optimization, like speeding up a function that takes two seconds to run by shortening it by only a couple instructions.
I love a straight-6 so much that I drive a car that uses two of them joined at the crankshaft! Each I6 has its own ECU and is entirely unaware of the other. Crude, but very smooth nonetheless.
There's potentially an even better option than the I6 layout: opposed piston I3 2 stroke. Same number of power pulses per rev as I6 4 stroke, no valves, no cylinder heads. It seems that these guys solved the oil loss problem and by using 2 injectors and some awesome combustion modeling they've been able to beat emissions standards without after treatment: https://achatespower.com
My first car, a 1965 Rambler, had the venerable AMC 232 cubic inch inline 6. It had decent torque, was thrifty, and proved nearly impossible to kill. Best of all, in the mid sized Rambler the I6 left enough room in the engine bay that I could stand beside the engine— under the hood- to work on things.
Spark plug replacement, points change, air filter… even things like water pumps and carburetor were trivial to work on.
Today’s cars are better in almost every way, but I sure loved the simplicity of that engine.
Also: I’m a little surprised the article didn’t make mention of a similar ( but slightly different ) engine. The mighty Mopar slant 6, which is legendary for durability. Maybe we’ll get a newer one of those, too!
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[ 5.2 ms ] story [ 57.2 ms ] threadB58 (BMW) is super reliable & high performance
same as the I6 used in certain landcruisers & other Toyota cars etc
though now of course - with super cheap solar etc - if you can go electric go electric but if you've to buy an ICE car - yeah buy an I6 - fuel efficient & performance & reliable
The Cummins 5.9L is excellent, particularly the 12 valve with P7100 pump. Awesome low end torque.
From Mercedes the M104 and OM606 are phenomenal. Powerful, efficient, incredibly reliable. The only drawback is the aging engine management software is not very well supported by aftermarket code readers anymore. In the case of an OM606 you can fix this by deleting the ECU entirely and installing an M pump from an OM603, or replacing the ECU with a DSL-1 standalone unit.
Dad has seen AMC I-6s go 400k before the transmission died and ended its run.
https://en.wikipedia.org/wiki/Cummins_B_Series_engine
Badging a Mercedes as an AMG and asking the price for it and you just fit turbos on a 4 cylinder.
It's a production 2.0L 4-cylinder engine making (in the most powerful config) 350kw. From the factory. Insane.
IDK why they don't just tax the actual fuel used like the rest of the world (not that they don't do that).
It does not hurt that you can easily get 200+ horsepower from the factory with one, either. My car is a series hybrid with an Atkinson-cycle I4 but it still bursts to 200hp because it's a hybrid.
Australia was awash in I6 motors, from the GM Holden motors, the Ford Falcon engine and the Chrysler slant 6 that got replaced by a locally developed version of a Chrysler 6 that was never finished by the US corp. they were all boring, mostly durable, mostly reliable engines for a family car.
Even BMC/Leyland had one. Uniquely they fitted it across the chassis of a land crab derived vehicle which showed why the I6 was ill suited to being packaged as anything other than in line with a rear drive drivetrain.
The V6 fits better in front drive cars for obvious reasons.
Hybrid cars change the equation somewhat, the skateboard chassis doesn’t seem all that suited to an I6 but here we are.
Chrysler have unfortunately found out that no matter how good you make one, customers still want a V8 and I concur.
But have to admit there is a part of me that would really love to drive something like the BMW M340i [1]. And the gas mileage (26/33 MPG) isn't even too bad.
[1] https://youtu.be/kr-h9T42NAI?si=IZaDC9UqAsUtjQN9
It is awesome. Incredible power. Silky smooth on highway. Sounds like a beast on start up. I regularly get 36/37 mpg on a long drive.
I prefer the sound of the B58 in the m340 over the S58 in the m3 but they are quite different engines. And way different power. But straight-six throughout.
Still think one of the best engine sounds out there is the s54 in the 2001-2006 m3
Why anyone thought "inline" was a better prefix, I have no idea.
Smooth, and sound great.
Automotive myths that won't die. 'Stroke' doesn't make more low end power than bore, displacement is displacement.
"Leverage is leverage."
Short stroke is exactly the same as being in a high gear at all times.
If it was such and advantage, wouldn't all performance engines have much longer stroke?
The newest Corvette ZR1 makes 1064hp from a 4.1 inch bore and 3.1 stroke. How much power are they leaving on the table by not making it a larger stroke than bore like many inline 6's? (Hint: inline sixes don't have larger stroke than bore for "torque")
Any change in power from a larger stroke is due to the larger displacement. It goes up with a percentage of the increase. Nothing to do with the leverage of the longer stroke.
By the way if you work the math out on that, it's not significant. And there are many other things that go into the losses of and engine turning. It's such a useless micro optimization, like speeding up a function that takes two seconds to run by shortening it by only a couple instructions.
Spark plug replacement, points change, air filter… even things like water pumps and carburetor were trivial to work on.
Today’s cars are better in almost every way, but I sure loved the simplicity of that engine.
Also: I’m a little surprised the article didn’t make mention of a similar ( but slightly different ) engine. The mighty Mopar slant 6, which is legendary for durability. Maybe we’ll get a newer one of those, too!