Seeking Advise on Recommended Tire Pressure

Tons of threads on the subject. This one is short and sweet.

http://priuschat.com/forums/prius-v-fuel-economy/99322-tire-pressure-2.html

For more information do a Google search with the following format.

siteriuschat.com tire pressure

 

Toyota's recommended pressure maximizes comfort. Higher pressures will ride rougher.

The maximum safe for your tires is molded into the sidewall of your tires. I would start with 2 pounds less for the fronts, and 4 pounds less for the backs. Watch tire wear and be aware of your comfort level, and adjust.

 

After reading through several threads on Prius tire pressures, I have decided to stick with "cold"* pressures that are close to what is on the door. I live in the sunny/rainy/hilly/curvey Pacific NW and value shorter stopping distance and handling over another mpg or two.

Do you wonder what the proper way to set your tire pressure is? Here is what Toyota has to say ... google toyotapart sb-0345-08 pdf Tire Inflation Pressure Compensation and Adjustment.

Did you know that the tire shop or the dealer almost always sets your tire pressure incorrectly?

If you get your Prius back and they have set the pressures to the door specs then they are under-inflating your tires. If they set them to 40/40 then they are closer but again incorrect. The 40/40 most likely keeps the tire monitor from complaining. The 40/40 has nothing to do with over-inflation to improve mpg ... it is not the same as setting your "cold"* pressures to 40/40 ... your tires are usually not "cold"* at the dealer or tire shop.

The upshot is to reset your tire pressures when you get home or tell them what to set them at (see bulletin).

Notes:
- Cold tire pressure is your car sitting outside in the shade for more than 4 hours. It does not matter if it is 30 degrees F. or 100 degrees F. in the shade. If the tires are not "cold" you must compensate the pressure to get it right.

- If you reset the base cold pressure higher, as many advocate in here, then you must reset the tire pressure monitor or it will complain. The setting the pressure procedure does not change. Be sure and tell the dealer or tire shop what to set your tires at (see the bulletin) or they will under-inflate them (even at 40/40).

- If you set your tire pressures in your garage then be sure and adjust the pressures as outlined in the bulletin. This is really important in winter if your garage is heated.

- The dealer/tire shop does not take the time to figure out the correct pressures or train their service people to do it right. So they use a formula that is usually close and won't under-inflate.

- The difference in pressure from front to back is due to less weight on the back tires. You don't want the back sliding out on an icy/wet curve before the front does. If you load up the back with real heavy stuff then you need to see the manual for pressure adjustments and advice.