Hey guys,

This is gonna sound pretty dumb but I think my tires are really low on air, and I don't know what to fill them to. I don't even know what tires they are or what they should be filled too. It's too dark to go look now, and I'm gonna fill them tomorrow morning before school so help would be great.

Can anyone else explain to me the what something like 235/65-15 means? That's just a number I saw once, not on mine though.

Thanks

 

Since it's getting late and you're probably not going to get any answers by tomorrow, I guess I'll throw out a decent, very general number:

32



It wont be the best for your tires, but it's more complicated to get them perfect. 32 is safe.

 

About tire size. 245/50/16

245: Width of the tire in millimeters.

50: Sidewall height, as a ratio of the width.

16: Size of the rim the tire fits in inches.

 

So around 32 is good? Good for pothole-filled ghetto roads? I hope!

 

the numbers you refer to like 235/60-15. the first one 235 is the width of the tire in millimeters. the second on you mention is how tall the tire is from tread to the bead in percentage of the width. so like in your above tire it is 141mm from bead to tread (60% of 235). the last number is rim size in inches.

as far as best air pressure there are a lot of variables there. I would say generall number between 30-35psi but take it with a grain of salt and listen here for some better replies from our other members

 

If your tires are stock size, your door placard with provide the info you're looking for. My IROC, for example, takes 30 cold.

JamesC

 

Just look on the sticker on your driver door. It'll tell you proper tire size and PSI rating.

 

can't that even vary though depending on tires? even using same size some have different amounts of sidewall flex, and so forth I thought

 

It must. 30 produces center tire wear on my rears. I now run 28 rear and 32 front on the formula.
The gta gets 27 in the rear and 32 in the front.

 

There are no stickers in my door, it looks like they were removed. but its almost time to put her away/sell her, so ill worry about when i get new shoes.

 

It most definately does depend on the tire. Those specs are for the factory original tires (Size AND Brand).I have run many sets of upper end tires on my Camaro for years. One of those sets was the great Goodyear GS-D3's. I ran those for about 3 years and got about 25,000 miles on them using a cold PSI of 49 fronts and 46.5 rears. Those are a 51 psi max tire. The tires I have right now (WHICH ARE CRAP- in case somebody has missed me saying that in past posts around here) are BFG KDW with a max psi of 44. I run 38 in the fronts and 36 in the rears- g0d these tires suck, did I mention that?

 

Why don't you like the KDWs? I have the gForce Sports and I love them.

 

You made me look! But I see you don't live in California, lol.

But yes, 32 is a good, all 'round, general, safe tire pressure to run in just about any tire on just about any car or light truck. Anything more than that will most likely cause the tire to wearout prematurely in the center. And contrary to what many people say about today's "better," more "technologically advanced" tires, at more than 32psi, they WILL wearout prematurely, too.

But I suppose "prematurely" depends on what people want or expect from their tires. If you drive like you're always running a race, either on the streets or at the track, then your tires prolly wearout unevenly anyway, so you might not even notice specific wear patterns from possible over-inflation. In that case, you might consider 15,000-20,000 miles as being good.

But for me, if I get less than 40,000 out of any set of tires on any of my cars, then I'm disappointed. I want my tires to wear evenly and last. And at tire pressures of 30-ish(28-32 psi), they ALWAYS wear evenly and last, at least, that long. Besides, tires are expensive! I don't know about all of you, but I don't have $500-$1,000 to drop on a set of tires every year or two.

Like JamesC mentioned, the door sticker on these cars specifically says 30(for 245/50-16 tires), and from my experience, that's what's best to run if you want the tire to "live a long, healthy life," even in the 21st century.

 

I still say it depends highly on the tire, weight, and suspension. I have had a celica that I would put 35psi front and back. I shouldn't of though. the the rear ***** out on the center while the fronts wore out on the outer edges.
my honda on the other hand same tires in all four and teh sticker says to use 25psi in all of them. the fronts and back are different tires. the fronts I have to use 30 and the rears 25 works fine. my mazda on the otehr hand has 4 different tires. to prevent wear on them I have to go anywhere from 30psi up to 40psi depending on the tire.
none of these cars use the door ratings. as they don't work.

 

The day you decide to lay out some cold hard cash for some quality tires is the day yoiu will learn how wrong you are. I gues you missed my post above where I stated as fact that I ran 49psi in the fronts of my Goodyear GS-D3's and was able to get 3 hard years and 25,000 miles out of them with that "overinflated I guess" pressure in them at all times.

 

I have owned so many setof of BFG tires I lost count. I used to hold stock in BFG Comp Ta's back in the 80's. BFG is terrible now. I tried these off of recommendations from people on these boards and I will never listen to advise from anyone on here about tires again. I have not ried the G-force tires but reviews and track tests (Laptimes etc) show the KDW to be superior to the G-force and I can tell you first hand the KDW sucks. Over 85 mph and they dance about with the slightest steering imput. At even 2mph they have very low steering wheel feeling, they feel and grip like the tire is half the size it is. They lock fairly easy, and I would rate braking their best characteristic. I get 2nd gear chirps out of them with a pathetic 160 hp 2.8 V6- that should not happen. Transistions- OH MY G0D, were do I begin- they are sooo damn unpredictable it is downright scary wiggling the steering a tad searcing desparately for where the grip is because they go out entirely and quickly, then come back just as abruptly jolting you in g0d knows what direction whether the fronts come back into feel first or the rears do. I hate these with a passion I do not even like driving this car anymore and have been waiting for the wife to wear them up. I know tires, trust me, I have owned well over 40 sets of various HIGH END steeet tires over the ears as well as many racing sets also. I even own a few sets of racing slicks over the years and numerous DOT rated 'r' compounds.


My Goodyear Eagles- http://www.cardomain.com/member_page...2_120_full.jpg

 

You should bolt up my rears (Bridgestone RE750's) to your car and notice the difference... probably none. Tons of grip, unpredictable as all get out. I hate them as much as you hate those BFG's.

Tire pressure is dependent on the contact patch only. Most tires will run and wear correctly with the factory pressures. Generally you'll run less in the rear since there's less weight in the rear. I run 32/27 in one car, and 35/33 in the other. Different weights, different tires. IIRC the latter is rated 50psi max but running that much pressure resulted in poor handling and bad wear pattern. You'll need to feel out your own combo to get an ideal pressure for what you have.

 

lol, I'd know that demeanor anywhere. Dean!

25,000 miles, huh? You can spend a lot less money to get the same results.

I will agree with you on BFGs, though. But I had Comp TAs, not KDWs. That was in the mid '90s, and I wasn't impressed with them. But that's probably when you still liked them, right?

 

you have no idea what one of these cars can do. naive as everybody else til you take a ride. your car will not hold a candle to mine with even the crappy BFG's on it. And no, I was talking the 80's and BFG. Only one local has been in this car and he was amazed and humbled. Many locals have witnessed it in person, but only one has been in it. I think one quote was, 'the license plate should be your first clue and should be read as a warning label.'


edit- I dug up a video I had from a few year back showing how radical this car brakes alone. You think your car can anywhere close to this you are high- You need the brakes, suspension and tires to perform this well. THis happens to be a DOWNHILL stop from 80mph with a slight lockup form tires overheating a tad. Try that on your tires and brakes and you would skid right through that intersection and not even stop at the other side (Unless you hit something) You think an ordinary tire and car can come close to this then you are in just plain denial- I know tires. If you listen close to the braking zone, you can faintly hear in the video the bitchen sound this car makes when under hard braking. It is a very distinct and unique whirling down noise. I have had people next to me when I come down to a stop tell me it sounded like a small jet plane stopping next to them- its alot more distinct in person.

http://www.zippyvideos.com/681124941...ilwaffarn_010/


Its just hard to explain around here without sounding arrogant when I darn well know from experience time and time again when I know people just honestly have no idea what my car can do. People just think they know something because its all they have experienced.

And to futher add to this for anybody else reading this that does not know me, This car is a 2.8 V6 automatic- watch and be amazed just how well one can scoot- I built this for my wife to drive daily- its her version or a soccer mom minivan. Its not my racecar.

 

Thanks for the help guys...

I got off my butt for once and checked my pressure and I was 30 front, 28 rear. Guess my eyes were tricking me...

 

It's just my own personal preference, but I like to run my tires on all my cars at 40 psi.
Right or wrong, I feel that a slightly harder tire has less rolling resistance, runs cooler, and will last longer, than a slightly under pressure tire.


Leon

 

I can't speak for the KDWs, but I do have some experience with gForce Sports. Best I can say is that they're an 'OK' street tire and no more. Good straightline traction and good cornering grip doing either by itself, but not very good at doing more than a little of each at the same time. Firestone SZ50EP's were MUCH better tires. And for that matter, the RE750's on a different car have better behavior.

The gF S might make a good drifting tire though, once you've had enough practice at finding where cornering + a little throttle = tail comes around.

As for inflation, that really depends on tire size, wheel width, amount of load carried, alignment settings, and your driving just as a start. But as long as the tires carry a rating adequate for the car (the load index number that should be somewhere in the mid 90's for these cars) low to mid 30's up front and 2 - 4 psi less in the rears is as good a range as any to experiment within.

Competition use, such as autocross may well work better with 10 or more psi higher. Then again, you shouldn't be expecting to normally drive so hard on the street that you feel any need to keep the inflation pressures up at your competition specs all the time.


Norm

 

Take the tire sticker on the door with a grain of salt. All manufacturers post those pressures for ride quality not tire wear. They could care less if you get 25K or 50K from any tire. Check with the tire manufacturer for what pressure gives the best wear and performance from a given tire.

 

I have a brand new set of Aurora tires on my Iroc and I'm trying to figure out what pressure to put them under. They're all sitting around 36 psi but the tire says that 51 psi is the maximum pressure. Any ideas?