What tire pressure do you get the best mpg at?

I get around 31 mpg in my 91 2.0 litre Camry with air pressure in the mid 30s, I am thinking about trying 40 pounds in each tire.

 

I have experimented with various pressures on both my o2 Prius and o5 Accord hybrid.

Max mpg seems to come from max tire psi stated on the tire sidewall.

Its unfortunate, the ride is more hard, but mpg is way up there.

On my Prius, my max tire pressure is 51psi. I run 50.

 

Right now I'm on an older set of tires so I don't mind experimenting.

I first started thinking about upping the PSIs after riding my bike with a low tire, which felt like dragging an anchor, even on level ground.

**Somewhat off topic, has anyone else discovered that some bike tire pumps also work on your car tires? I just found out last week that my cheapo Bell pump works on my car, which means no more $.75 to an air pump which doesn't work.

 

I go with the max stated on the sidewall, 44 in my case.

I've done this for 20 years and have never seen the "center wear" that many people assume will result.

I'm considering upping to 48 and evaluate.

 

Interesting that you mentioned this...I dont know about other states, but I just found out that in CA the air/water pump is free, even if it has a slot and signage for coin deposit. You have to ask the attendance, of course, and they would turn it on from the booth. I asked around and some say it's actually a law, but I think it's complimentary from the station. I've done this without trouble many times at many stations and without pumping gas first.

 

Yes... any bike pump will work on car tires.
Street bike tires are usually 65 psi.
Most car tires are about 35 psi.
-John

Oh... and yes, more psi = more MPG.

 

Be careful going over the max psi rating. More pressure does gives better mileage but also increases the risk of tire damage or catastrophic failure (blowout). Also some insurance policies my limit your coverage if you knowingly introduce an unsafe condition on your vehicle - like overpressure.

 

OK I played a lot with this and while you would think that MAX psi will pay dividends in the FE department, it did little in reality. What I did get was a better handling car in both dry and WET conditions. The FE increase from the recommended PSI was not noticeable (going from recommended 31 to MAX of 51 did little to improve FE).

NOTE: the ride is a little firmer but not that bad.

 

Thats amazing Livvie.

On my o2 Prius I lose about 1 mpg per pound of pressure.

I do NOT have low rolling resistance tires, maybe you do and maybe this makes a difference.

When my pressure drops to 45psi, I struggle to get 50mpg.

 

So far so good. By estimating from my mileage (182 miles with slightly more than half a tank left) it looks like upping my PSIs to 40 is getting me about 33+ per gallon * 2 mpg over the highway rating for the car in 50/50 city-hwy conditions