Tire Pressure - Honda Prelude Forum

Shukuchi_SH · 02-10-2002, 05:57 PM

What's the perfect tire pressure you should have?
Currently all four of my tires are at 35psi. Is that normal?
How many psi you have on yours?
What's the right amount of air for good gas mileage? Ideal for racing and Casual driving?

Thanks!

5Gen_Prelude · 02-10-2002, 07:55 PM

It all depends on the tire size - stock is 32, my 215/40-17's are 35.

DaRawkus8 · 02-10-2002, 08:12 PM

Well, on my stock honda tires (Bridgestone 205's) I run 35 psi all around ..

EviLPenEviL · 02-11-2002, 12:13 AM

Quote:

Originally posted by DaRawkus8
Well, on my stock honda tires (Bridgestone 205's) I run 35 psi all around ..

Darth Luder · 02-11-2002, 05:41 AM

Please do not quote only post.

I ususally run 35 all around for just driving around town. Autoxing is a different story..

KentRagay · 02-11-2002, 05:52 AM

what would the ideal psi be for 225/40/zr18 tires (falken)?

Prelude1897 · 02-11-2002, 08:06 AM

Look in your door jam..It tells you everything on your car from the tire pressure to the color code of your car

shock · 02-11-2002, 01:04 PM

i recommend at least 1 or 2 psi over 32...the stock tires are a little too floppy for city driving at 32

Mz3silver · 02-11-2002, 01:42 PM

Quote:

Originally posted by shock
i recommend at least 1 or 2 psi over 32...the stock tires are a little too floppy for city driving at 32

Interesting.. I always wondered. I used to run 34-35psi and noticed uneven wear... Wore out more in the center than sides.. so back to 32 psi for now.

Anyone notice the same?

2kPreludeSH · 02-11-2002, 03:49 PM

I run about 33-35psi.

Mr Ludecrs · 02-11-2002, 03:59 PM

We've been running 32-35 depending on how stiff we want the ride. For everyday driving, we'll keep it at 32. If we know more enthusiastic driving is on the menu, then we up it. I've only autocrossed it once, but I believe I put the tire pressure up to near 40 all around for that.

I've noticed very slight uneven wear due to negative camber. We use to have the car REALLY low, but have raised it up a bit. Don't ask me how low it is, I have no idea. http://members.aol.com/onesi2nv/ludetracks2.jpeg for a pic

5Gen_Prelude · 02-11-2002, 09:17 PM

Quote:

Originally posted by Mz3silver

Interesting.. I always wondered. I used to run 34-35psi and noticed uneven wear... Wore out more in the center than sides.. so back to 32 psi for now.

Anyone notice the same?

Yup - and that's the exact sign of over-inflation. Wish I had taken a picture of my stocks - but suffice it to say, the last guy obviously overinflated the tires thinking that it would provide better all round grip. Truth is, overinflation decreases the contact patch - sure your sidewall is stiff - but you got less rubber on the road.

kenchan · 02-11-2002, 09:58 PM

215/45/17's 32 lbs. all around summer time. 34lbs winter.

dohcpower v2.0 · 02-11-2002, 10:05 PM

33-34 front, 34-36 rear.

TCB007 · 02-12-2002, 03:56 AM

..I'm running on 215/45ZR17 Dunlop SP Sport W-10s. I've been keeping them at 35-38psi cold! is that too high?

Darth Luder · 02-12-2002, 05:49 AM

Quote:

Originally posted by 5Gen_Prelude

Yup - and that's the exact sign of over-inflation. Wish I had taken a picture of my stocks - but suffice it to say, the last guy obviously overinflated the tires thinking that it would provide better all round grip. Truth is, overinflation decreases the contact patch - sure your sidewall is stiff - but you got less rubber on the road.

Actually, you flatten out your contact patch first. In order to really get the patch smaller, you have to be going into the upper 40's and 50's in tire pressure. If you drive faster than say highway speeds at all, then you are supposed to increase pressure for safety concerns.

16vdohc · 02-12-2002, 10:17 AM

I run my Yokohama parada 205/45-16 at 40 PSI because when you go to a lower profile tire (i.e. 45), you will need more pressure in the tire (because there is less air than say a 50 series tire) to hold the weight of the car up. Just something that I have heard.

5Gen_Prelude · 02-12-2002, 09:59 PM

Quote:

Originally posted by Darth Luder
Actually, you flatten out your contact patch first. In order to really get the patch smaller, you have to be going into the upper 40's and 50's in tire pressure. If you drive faster than say highway speeds at all, then you are supposed to increase pressure for safety concerns.

Actually no, even 5 psi will degrade your performance of your tires. And the highway deal is opposite (to a very small degree). The reason behind it is that your psi will increase if you are travelling for long distances. Why? The tires heat up and don't have time to cool down like normal. They will increase in psi by up to about 3 psi on long highway trips, thus over the recommended amount. Increase the tire presure for long highway drives simply compounds the problem.

Darth Luder · 02-13-2002, 10:31 AM

Quote:

Originally posted by 5Gen_Prelude

Actually no, even 5 psi will degrade your performance of your tires. And the highway deal is opposite (to a very small degree). The reason behind it is that your psi will increase if you are travelling for long distances. Why? The tires heat up and don't have time to cool down like normal. They will increase in psi by up to about 3 psi on long highway trips, thus over the recommended amount. Increase the tire presure for long highway drives simply compounds the problem.

Performance DOES go up when you increase tire pressure. It will flatten out the tire and change the slip angle of the tire. That is why when you are autoxing or road racing, you want higher pressures up front to get better grip up front than the rear to get some oversteer. I know about the pressure increase, but it happens everywhere, not just the highway. The increase in pressure is constant however and does not keep inflating once it reaches 3-5 psi. It will not go down until it cools down. Even the sun will keep the pressure up or increase pressure when sitting for a while.

The safety concerns with increasing pressure when you drive faster have to do with unseating and rolling over the tires. Its even printed in the owners manual if you want to double check.

5Gen_Prelude · 02-13-2002, 07:18 PM

When Autocrossing your speed is so much less than highway speeds, that's why it can help with cornering and such. For daily use, stick to the recommendations of the car manufacturer and in the case of after market tires/wheels, the tire manufacturer.

By the way, a higher than normal presure will increase the chance of a blow-out and decrease your braking ability as well, that to me is a big

Darth Luder · 02-14-2002, 05:23 AM

The setup is the same for time trialing or road racing. Racers have been using this setup for years also, so its not something I am just saying. Also, there is literature on the subject in several books. You will not notice a difference in braking either with a higher pressure tire. You are not skipping on the pavement, you do have better grip so why would your braking be effected? I will look up the page in the owners manual at lunch and post that up.

And the risk of a blow out is the same as with any pressure tire, not just because the pressure is up...

Darth Luder · 02-15-2002, 05:44 AM

Found the page number, 257. Gives 41 psi for driving over 100mph to reduce the risk of suden tire failure.

5Gen_Prelude · 02-15-2002, 08:25 PM

I'm just reiterating what is plastered all over the internet, not interested in trying to make you change your mind - it's clearly made up.

Go do a search on over inflation if you don't beleive me. If you want to go over 100 mph on public roads and risk a blowout, by all means do it. I have no doubt that you are correct in the assessment of track conditions, but that's not what 99.9% of driving a lude is about unless it's strictly a track car. High pressures are detrement in any adverse conditions you can think of and if you do run over a pot-hole (damn that sucks!), you are more likely to pop a tire if it's overinflated.

For maximum treadlife and gas mileage, stick with the recommendations - especially if you live in freaking rain forest

Darth Luder · 02-17-2002, 07:25 PM

Well, you should know better to not believe what you read on the internet as what is right. There are lots of people that post up the wrong info on tire pressures. The Firestone recall with tires seperating tread from the rest of the tire blowing out was caused by underinflation...

Its in the owners manual. I guess the engineers are wrong again.....

darklude · 02-17-2002, 11:08 PM

what would the best tire pressure be for stock sh wheels / stock tires for mountain / road racing?

PilotSH · 02-18-2002, 01:30 AM

Alright, lemme impart my "wisdom" onto this thread

Lets get some basics straight first. A tire is never perfectly round (unless your flying in the air!) Where it contacts the road, the tire bends, or deforms a little. Just look at your car when it is sitting on the ground stationary. You'll notice that where it contacts the road, the sidewalls bulge a little and the tire flattens out a little. Anytime you have shape deformities, there is a buildup of heat. Since the tires actually deform quite a bit from a structural point of view, they heat up a lot (thats why manufacterers stress checking tire pressures when they are cold, ie not driven on at all within last 5 hours). Whether at 20 psi or 50 psi, the tire deforms and creates heat.

The most important thing about tire pressure is that it increases/drcreases the rigidity of the tire. Low = soft, flexible tire. High pressure = stiff, very firm tire. If you need a demo of how much it acutally changes the rigidity, push in your sidewalls when the PSI is at 20, then fill it to 40 and push in the sidewall with your fingers again. You'll notice a HUGE difference in rigidity.

OK, now that we have the basics covered, lets go into how they affect driving handling characteristics.

First off, when driving at high speeds, the tires are deforming at a higher rate, i.e. it rolls thru it's circumference 10 times in a second at 60 mph (thus deforming ten times) vs 5 times a second at 30mph. The more it deforms in a certain time spa