Suggestions/Opinions on optimal tire pressure

[Serjical]

Hey,
When I bought my car, I was pretty bad with paying attention to certain aspects of service, especially the tires. I wore out almost new Falken's in about 10,000 miles. It was ridiculous. Well, recently I invested a decent chunk of change into BF Goodrich g-Force Sport tires, and I want to make sure they last. I have a 3rd gen Protege, and the door placard says to put the stock tires at 32 PSI. Well, I have the same size as stock, but I think the pressure should be adjusted a little differently. I know the first thing people will recommend is to search, which I have been doing for the past hour. I was just wondering what everyone could suggest as to tire pressure that will maintain a long life on the tires, but also give me decent performance and good gas mileage. The 32 PSI I'm currently running is eating my gas like crazy, and I have a feeling my tire life will be affected as well. Arizona's cold weather and hot weather has about a 20 degree (Farenheit) difference right now, so that would be 2 PSI that I need to account for. Anyways, should I put more air in the back tires to lessen the understeer, or more in the front because of the extra weight? And how often do all of you rotate/align your wheels?

 

[Action Jackson]

I rotate my tires every oil change -> 5000 km.

If you did a search you'll find that I like my pressures at 36/34 Front/Rear and I gave the reasons why.

 

[SciFiMan]

You didn't mention how your last set wore out so fast, and which Falken it was. Was it even wear across all the tires, and were you rotating them? If the wear is uneven this new set may have the same problem, and you can Google to find examples of bad treadwear to compare. Could be an alignment problem, or if you are always doing burnouts, can't help you with tirewear there. Also pressure used can depend on the tire, and how you feel about that tires sidewall stiffness. My current tires have soft sides so I run 38 front and 40 rear (they have a max of 50psi) because I take corners quite hard. Yes, more air (to a reasonable limit) will reduce rolling resistance and improve gas mileage. A bit more in the rear tires will reduce understeer which is why I do it until I get around to adding a rear sway bar.

 

[apexlater]

What kind of car is it? That will give us a starting point. I'm not familiar with the Sports personally. I have the Kumho MX and I run 34front 35rear COLD. Then as they get up to temp on the street they are where I like them.

It's hard to get the best of both worlds, performance and MPG. Really high pressures will allow you to drive on less tire and increase MPG and increase center tire wear. Too low and you wear out the outsides and get crappy performance. In most "non-max-performance" tires the sidewalls are softer. You can increase oversteer by LOWERING the pressures in the REAR to allow the shoulders to roll more creating a more progressive oversteer. Cranking up the rear pressures will provide a smaller contact patch but result in "snap" oversteer. You will probably have to just do some of your own testing to suit your needs.

I rotate every 3K miles/oil change, or I just look at them when I have them off for Autox and put the ones with the most tread up front. Your alignment will affect your tread wear too.

 

[Serjical]

My last set were Falken Ziex Ze502s. And part of the problem was I waited too long to rotate them, and also I didn't check tire pressures for a long time, so I was running low on them for a while. But after I started checking tire pressures, I put them too high, almost to the max, because I wanted better gas mileage. Now I'm trying to find a comprimise. I guess I'll just have to try different pressures out and see what works best. By the way, has anyone tried one of those electronic tire gauges? They have one at Radio Shack for $10 that looks pretty interesting. I just don't like using the gas station's gauges, because they're pretty hard to read sometimes.

 

[viVid]

You can increase oversteer by LOWERING the pressures in the REAR to allow the shoulders to roll more creating a more progressive oversteer. Cranking up the rear pressures will provide a smaller contact patch but result in "snap" oversteer.

Never considered that... good info.

 

[Stormtrooper77]

32 - 35 psi is optimal. I would lighten up on the right foot.

 

[apexlater]

32 - 35 psi is optimal. I would lighten up on the right foot.

Nicely put. I got 32.5 mpg this last tank from just pussy-footing it and keeping everything under 3500rpm.

 

[Serjical]

Yeah, I usually try to drive easy as much as possible in order to keep my mileage up. But the tire pressures affect it a lot as well. Anyways, thanks for the advice everyone.

 

[tracknfield423]

Hey guys, I have kumho exctesa(SP) tires and it says max tire pressure 50psi, what should i put my tire pressure at? i don't know much about tires so any info is helpful

 

[chaosProtege]

read the posts above yours....all of them.

 

[Serjical]

Trust me, you don't want to go anywhere near the max on your tires. Especially if you plan to keep them for a while. I found that out the hard way.