Thread: Tire Pressure - Factory Defaults and MPG Comparisons
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Old 08-15-2007, 07:39 AM
jdenenberg jdenenberg is offline
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Real Name: Jeffrey N. Denenberg
Location: Connecticut
Hybrids: 2004 Prius
Posts: 228
Default Re: Tire Pressure - Factory Defaults and MPG Comparisons
Quote:
Originally Posted by tekn0wledg View Post
Okay, I've had my Prius over a month now and I checked my tired pressure yesterday. The first thing I noticed was how low the factory default tire pressure must be. My front Tires read 36 and 35 and the two back tires read 32 and 34. Judging by this, I am guessing the factory default is 36/34, or thereabouts.

Does anyone know what the factory defaults are?

Knowing that I have been getting around 60mpg the last two weeks or so, I am going to raise my tire pressure to 40/38 to see how my mileage may change to do some testing myself.

I am wondering if any detailed analysis has been done comparing the relation of MPG and tire pressure. I know that many have said their higher tire pressure has resulted in higher FE, but I have not seen any graphs or reports on this topic in detail.
Assuming that you have the standard Prius (not the Turing) and you have the stock Goodyear Integrity tires, the default PSI is 35/33 as shown on the driver's door jam. I ran mine at 42/40 which is still below the MAX rating as shown on the tire sidewall. They were worn out at 44,500 miles and my present tires (Michelin MXV4+) are at the same PSI and now have 49,000 on these great tires, but will probably have to replace them this fall.

JeffD
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