Higher tire pressure on old fashioned cars too?

[GreenMachine]

Is anyone increasing the tire pressure on their "other" cars too? Seems like it should increase the mpg for them too? Does it work?

If so, are you using the same percentage increase over the OEM recommendations? If not the same percentage, what is your theory?

[Jack 06]

Hi, Machine---I'm following you around today.

Yes, I've been "overinflating" tires on all cars for 25 years. And yes, it always results in a little better MPG.

However, two caveats. One, it's all about the "footprint" of your tires on the road at a given split-second. Smaller footprint = less friction = less effort. But not all car suspensions react as forgivingly to a harder-ride situation. And it DOES mean you're sacrificing a bit of safety in a "bounce" scenario, though it usually won't bite you.

Second, Prius tires can handle more overinflation than tires on other cars. It's all about the weight of your car in relation to the max. pressure printed on your sidewall. I'll usually go to within 3-4 pounds of that max, unless it gives me TOO hard a ride---then back off a little.

Then again, I've always liked the "live feel" of a slightly harder ride. Others like the cushier feel.

[rogerSC]

I think that this idea makes sense on any car. If your tire pressure is low, or if the manufacturer is using a lower tire pressure recommendation to "give a smoother ride", I'd try raising it from there (without exceeding the maximum for the tire, of course) on any car. Your mpg will go up.

-Roger

[GreenMachine]

Originally posted by Jack 06@Nov 19 2005, 05:20 PM
Hi, Machine---I'm following you around today.

Yes, I've been "overinflating" tires on all cars for 25 years.  And yes, it always results in a little better MPG.

However, two caveats.  One, it's all about the "footprint" of your tires on the road at a given split-second.  Smaller footprint = less friction = less effort.  But not all car suspensions react as forgivingly to a harder-ride situation.  And it DOES mean you're sacrificing a bit of safety in a "bounce" scenario, though it usually won't bite you.

Second, Prius tires can handle more overinflation than tires on other cars.  It's all about the weight of your car in relation to the max. pressure printed on your sidewall.  I'll usually go to within 3-4 pounds of that max, unless it gives me TOO hard a ride---then back off a little.

Then again, I've always liked the "live feel" of a slightly harder ride.  Others like the cushier feel.

[snapback]158300[/snapback]

LOL, Hiya Jack. I was wondering who that was on my six?

Thanks for the advice on the pressure, makes a lot of sense.

The car I am most interested in is a 2001 Honda Civic which should be somewhat similar to the Prius as far as handling the extra pressure. I will try your method and see.

[tumbleweed]

It works good for me also. My previous car, '98 Accord, had a recommendation of 35 lbs in all 4 tires. I increased it to 42 lbs and my highway mileage went from 29 or 30 mpg to 32 or 33 mpg.