How much gas would Americans save annually if they kept tires inflated and cars tuned?

Question

How much gas would Americans save annually if they kept tires inflated and cars tuned?

Answer 1

Not as much as if we took other steps. However, not only would we save gas if we kept our tires properly inflated, we would also get a longer life out of each tire. The cars would also handle better, so there is a lot more than just fuel economy to gain from properly inflating your tires.

Answer 2

The average driver would save all of about 70.00 per year. It's more being smart rather than saving a ton of gas.  Over or under inflated are a safety issue and as far as a tuned car, well if you like running the risk of breaking down and spending more for something that maintenance would have solved, well there again that's a no brainer.

Answer 3

There's really no such thing as a tune-up.  My car will run about a billion ignitions without a single misfire.  When it misfires, then, it's pretty obivous, and I have to fix it.  

My car has O2 sensors, so it always meters the right amount of fuel.  So really, the effects on the car itself are negligible. Old O2 sensors drift rich, but if you have a car built in 1996 or newer, even that doesn't bother the fuel mileage.

Changing your driving, and particularly driving less, is far more effective.  Slowing down is incredibly effective.  Try it.  

Most people want solutions that don't require any sacrifice, and this is one of those appealing ideas that isn't worth much.