Being wealthy adds nine more healthy years of life, says study (theguardian.com)

I'll wager a wealthy amount of money that the gap is going to increase at a faster clip

Because you cannot do a controlled experiment, it is probably impossible to control for all the variables that are all confounding each other... education level, IQ, talent for delayed gratification, etc. Wealth impacts all of those, but is also caused by them.

Depends, on how you drive.