Tire pressure of all-seasons
 

Hi all,

Just an FYI - when my FR-S came in, in early October, it came with all-season tires. When I was driving it the first few weeks the traction control was always chiming in and the back end was really squirrely. I thought it was the natural disposition of the car and was OK with that, but I thought it was more extreme than I was expecting.

After a few weeks my folks came to visit and my mom's car had a TPMS light, so I checked her pressures and adjusted accordingly. I decided it was time to look at mine on the FR-S and I found that all of the tires were set to 40 psi! Well that explained a lot! I adjusted the pressures to 35 psi and the car is now perfect - even on the all-season tires. That will be rectified in the spring with some new wheels and 255 Star Specs, but I thought I'd let everyone know about my experience in case anyone else has experienced the same but didn't think to check tire pressures. I haven't mentioned it to the dealership, but I assume that they came that way from Japan since I got it immediately off the truck.

Here's to more great driving weather! :happy0180:

Mine were also set at 40. When I realized it I did a face palm IRL.

I'm pretty sure the dealer checks the tire pressure as part of their predelivery inspection. The only reason that I can think of for over pumping the tires is because the general population doesn't check their tire pressure on a regular basis. It's safer to over pump a little (within reason) than to under pump and get a flat.

Just a FYI, under normal driving conditions, it should be 35 psi when the tires are cold.

Whats wrong with 40?

Recommended is 35.

40 wont make that much of a difference?

35 is the recommended optimal amount for the general population. In certain situations, you may want to be over or under 35.

As I said, 40 psi made the car overly touchy, with the traction control cutting in way too often.

I autocross a lot (really, a lot) and 5 psi makes a huge difference no matter what tire you're running. 5 psi too high on an all-season in the cold weather is asking for serious trouble.

yeah runnin' 40 instead of 35 "decreases" "rolling resistance" however you
DON'T want this condition in a snow covered road situation,as your grip will improve if the tires are set at the lower (p.s.i.) (softer rubber compound)
hence,the (all- season) designation.

it does make a difference. in winter conditions!

this is "dead nuts" accurate! loss of traction ,and subsequent "grip" is a very
serious condition when driving on "snow-covered" roads.

I was told in the past that they're over inflated for transportation purposes but yeah the dealer should set them right before you take delivery.

Air pressure gauge
 

A 5psi difference could simply be the diff between someone using an inexpensive gauge instead of an accurate digital one. If you intend to do any serious driving, invest in a good gauge and never assume.....