Let's talk tire pressure...

Tried several different combinations of tire pressures with my EP 20's, for me the best compromise is 39 front 37 rear.

 

Do not do any side to side!

A lot of people do front to rear 2 pound difference, 2 pound more in front. I do believe Toyota recomends this. It helps the car to track down the road better.

 

That infuriates me more because they never get my psi to the pressure listed on the door. It shocks me how little the dealer knows...at least one compared with others. There is no consistency with the service at dealers with this brand.

 

It's this way with most dealers. They have a high turnover rate because they don't pay well.
Techs go from dealer to dealer trying to find better pay and better working conditions.
Working for a dealer is difficult because they're cheap and don't care about the people they employ.
Only thing they care about is selling cars for as much profit as possible. The sales staff is even worse.
They have ZERO training and come up with all kinds of B/S. I had the last guy tell me he knows nothing about
cars. He was just someone they hired to try and sell a car because he had some people skills.

 

I have the same issue at the tire shop. I finally realized that they are filling tires/wheels that are warm, so it'll always be low when checked again cold. You'd think they would deliberately over-fill a couple pounds to compensate.

 

195/65/15
Michelin Defenders
40F/38R

 

Anyone keep mpg data records when using higher pressures than stated in owner's manual compared to the basic recommended pressures? That difference may of course depend on the tire, but I would like to see the approximate trade off for mpg gained vs increased pressure. I have the stock Yokohama 195/65 r15s on a 2012 and there should be enough of us to get a decent sample size for stable averages. Anybody else willing to keep track? Given the known inaccuracies of the displayed estimated mpg, we should probably state both displayed and calculated mpgs for each tire pressure.

 

Both of my 2010 Pruis vehicles have Michelin Defenders XT (195/65/R 15), which I keep at 42psi (front) and 40psi (rear)

 

I use the Toyota recommended tire pressures. A co-worker previously worked as an engineer for Toyota, and he recommended no modifications to the car. One must assume that Toyota has reasons for establishing specifications. However, I did try running 38 psi in the 13 inch tires and experience a significant change in ride quality.

 

Run the recommended Door jam pressure. I find no increase in MPG at 40/38-40/42... none, what so ever.

 

Thank you!

 

Engineer in what capacity ?

Toyota isn't the one that sets the tire pressure spec. It's set by the tire manufacturer. The tire plate in the door is a recommended pressure for best ride and handling. It's certainly not set for MPG's.
I found up to a 3 MPG difference over a 90 mile commute with higher pressures in both my 08 Prius
and my 2013 C. YMMV!


What vehicle has 13" tires ????

 

Quality Engineer and Purdue Engineering graduate. I meant the wheel size, in other words, the baby tires Toyota installs on the Prius. More than likely, you understood that point, but it's always fun to point out the little things when posting on these types of forums.

 

I guess they are 15 inch wheels, but they look like baby wheels and tires...that's my point. First car I've owned with such small wheels and tires.

 

For all us old people, You know who we are. 15" tires ar standard anything bigger are on trucks!

 

So, I guess that makes him an expert on tire inflation "VS" MPG ???

 

What's wrong with green caps? I don't have them, but I'll be installing new tires at Costco and they inflate with nitrogen.