running 40psi all around.

Hondas factory pressure is more towards comfort then anything else. you WILL be replacing the tire a bit early if left at 32 psi

I highly recommend a minimum of 35 front and 34 back. My dunlops are noticably smoother on road with higher pressure.

I didnt even lower the pressure when I went to friday night;s drags. Tire spin was smoother and although I got wheelhop, it was a bit less aggressive on my mounts and tranny.

Damn I have to fill those mounts! Hate wheel hop

 

Has anyone taken their tire temperature to check inflation pressure?

I know that motorcycle tires are designed to warm up and work best at slightly elevated temperatures. Too little pressure and the tire will be too hot. Too much pressure and it will remain cold. If you're already out for the day and want to know how the tire pressure works for your the weight, just putting a hand on each tire shortly after stopping can tell you if it's OK or way out of whack.

I DON'T know if car tires are supposed operate best at some slightly elevated temperature or not. I'm sure that running a tire underinflated will flex and heat it too much. Does higher pressure leave them too cool?

I've started inflating my tires to 36psi. That's a third of the way between the Honda-recommended pressure and the Dunlop maximum pressure. My fuel efficiency has been excellent, but I'm looking for more.

Thanks.

 

^That's very dependent on the tire. For your average all-season tire you are daily driving on the difference in temperature from pressure will be mostly irrelevant to traction and wear (within reasonable pressure ranges). Higher pressure will reduce the contact patch and in return CoF which is what gets you your extra fuel mileage.

When you start talking about "racey" compounds or track situations heat becomes an important concern for traction, but not so much on the street on your run of the mill 400 500 TW tires, they are designed to work in a wide variety of situations and climates.

Tire compound, width and weight are your most important concerns.

I run my tires 35psi all around. That pressure works best with my current tires and suspension for the best balance of comfort, traction and fuel mileage. I can tell when I need to air my tires up, the car stops "feeling right", and this is usually way before the TPMS comes on, usually around 32psi I start to notice.

 

Dude I'm thinking about lowering my pressure, like you I like to be close to 40 but these dunlops have AWFUL traction. I mean the car has no toqrue and I try to make a quick maneuver and they just break loose. I'd say I disagree with you on the longevity statement however, because you are making the tire harder, the rubber is going to wear faster.

 

Thousands of times, including checking the temperature variation across the tread to see hoewell the tire is working. tho ours were immediately coming off track. the F1 race TV has on car thermal TV of tires at work.
The yellow color is a good indication the tires are over 200F; black close to track road temp. Its an excellent assistance to setting up suspensions, including tire pressures.

ALL rubber tires are better at temperatures greater than ambient; those winter and all season and summer tires are designed to work best at temperatures higher than ambient, Winter tires a little above freezing (which is why they have no UTOG, because they know drivers will drive in temps higher and shred that rubber); all weather freezing to 180F; and summer 60 to 220F. Thats the design tread temperature ranges. Running all weather tires in 90F ambient on a heavy load at 100 mph is not recommended. When temps exceeed 220F the tread gets 'greasy' and traction falls drastically - worse it takes a number of laps to get the temp down. Ask any NASCAR driver or tire engineer.
On our Fit the preferred tire pressure and rim width is 195/50 section on 7" rims. Wider rims need too wide tires or too much air pressure to 'flatten out" the tread. Thats side to side, not circumferentially per se.
There's a reason 'tire-warmers' are used on F1; other series generally prohibit their use.
The working range for most all weather and summer tires is about 160 to 210 F and tire pressure matters when the tire tread starts to 'bow' and thats usually about 40 to 50 psi though heavier cars and wider tires of low section height can go more for autocossing and other short racing events. Its the tread temperature that heats a tire unless underinflated.
In any case too little pressure causes the sidewall too flex too much compounded by the flexing of the tread as it compresses coming in contact with the road as it rotates That is the reason why higher pressures yield better mpg because the 'flat spot' is reduced considerably and results in lower rolling resistance..
And yes too much pressure does result in tires running too cool except for a narrow babd and that is usually cooled by the sides of the tread; yes, that too narrow band is the reason traction falls a lot.
So choose your tires carefully for the use you expect; for most those all weather tires are best if you choose the right speed rating. Goning on track with a Musrtang GT oo T rated tires is stupidity at its greatest level.
Those speed level ratings are cast in concreteexceeding those limits is attempted suicide.
BTW 40 psig tire pressure may not be best for your Fit your tires may be difference, your suspension setup may be diiferent and you may drive different. It all matters so you have to experiment to find out whats best for you.
What you though there was some magical pressure? Sorry the magic number for you is yours to find out.
Still a majority here here use 40 psig cold, but not all, maybe 3/4ths.
cheers.

 

38 rear 35 front for me

 

handy sort of information has been wrapped up in the above write and i appreciate the efforts so valuable to us .. keep sharing such informative posts

 

If this is a zombie revival, I apologize...but I didn't see an answer to this question.

Does the TPMS need to be recalibrated if the driver chooses to bump the tire pressure up? Or should I leave it the way it is?

 

Don't do anything other then put the tire pressure where you want it. I have run my 08 and 09 Fits between 37 and 40. I really can't feel any difference on the road in this range, but it is a firm ride in this range compared to 32psi. The TPMS doesn't care what pressure you have until you go below approximately 28 psi, based on my experience of leaks and slow flats with both cars, at which point it will warn you.

 

TPMS only sets for minum pressure, typically 26 pdig so any pressure greater than that doesn't affect tire pressure monitoring sytems. The set point that triggers an alarm may be different if the kmake and model changes but not for a given car/

 

I'm on 34psi due to the tires I drive on (Bridgestone RE-11). I want a tad stiffer ride. Honda recommends 32psi for what there engineers will say is optimal performance on OE tires and suspension.

Keep in mind if the vehicle is OE, Honda will know what is best. That's why their engineers get paid the big bucks.

 

honda does it based more so on driver comfort

 

I run 35 psi front, 39 rear on my 2011 Sport M/T, since having higher pressure in back is supposed to reduce understeer. I don't know if it's that or the Progress RSB, but this car has the most neutral steering of any FWD car I've owned.

 

I use approximately the same pressures on both 08 and 09. Works great. Some people actually say the Fit wanders all over the road... I have never found this to be true on either car.

 

Opposite, but that's why it's neutral. I used to run similar pressures and yes, it's pretty neutral like that.

http://www.tirerack.com/tires/tirete....jsp?techid=58
EXECstudio.com - Tech: How to modify Oversteer and Understeer


I have been running 40F 34R with no rear sway and it's perfect now that i'm 100% comfortable with the car. The rear tire sidewalls don't roll nearly as much as the front for several reasons.

 

The Progress bar definitely loosens up the back end. A friend of mine did a track day in his Fit with a Progress rear bar. The day was damp; he spun off the track backwards so many times the officials finally pulled him in for a chat.
Interesting thought. My Fit didn't wander per se, but high winds and tractor trailer backwash would buffet it around uncomfortably. I put a Beatrush undertray on it and the buffeting disappeared almost completely. It also turned the car into even more of an offramp screamer.

 

I can't find the article where I originally read that lower pressure in front tires reduces understeer, but this article agrees with it.

Automobile handling: Information from Answers.com

I guess someone needs to do some skid-pad testing.

 

It's not really that cut and dry honestly.

What pressure does the tire fully load at? That will be different from car to car and from wheel/tire setup. I started at 36F/36R with my setup and I was seeing the fronts were rolling over the sidewalls in some extreme situations (this was causing the under) but the rear had a lot of room to move.

So I just increased the front until it didn't roll over anymore and decreased the rear because I didn't like how the rear was acting on midcorner bumps.

A tire has an effective pressure "zone", like a bell, so going up or down either side is going to decrease grip, it just depends on how you want the tire to react. I don't like sudden changes, although it may be "faster", so I lowered it. I could have raised it just as well, but I also don't like driving around daily with the rear end vibrating and the tires at 46 psi, which is probably what I would have had to put in them.

So the answer is: It depends.