What do you guys recommend for after market tire pressure on a C5 Vette

 

The pressure recommended on the sticker on the side of the door: 30 psi cold.

 

any tires 30 psi

 

 

Yeppers... 30 pounds

 

 

Does the 30 lbs also apply to Z06 tires and rims?

 

What does the sticker on the side of the door say?

 

There have been a lot of threads on this topic, you might consider trying a search.....

http://forums.corvetteforum.com/show...=tire+pressure

http://forums.corvetteforum.com/show...=tire+pressure

http://forums.corvetteforum.com/show...=tire+pressure

http://forums.corvetteforum.com/show...=tire+pressure

http://forums.corvetteforum.com/show...=tire+pressure

I'm sure there are more in the archives.....

 

I've got an '03 MN6 (non Z06) with chrome factory Z06 rims and tires. I was wondering if the Z06 sticker says 30 lbs or some other number.

 

The Z06 sticker says 30psi cold.

 

Correct tire pressure is not something that would be determined by the tire manufacturer, other than to state the maximuim recommended air pressure and maximum weight. The correct tire pressure would be stated by the vehicle manufacturer, as the vehicle manufacturer performs an analysis as to what tire pressure offers the best ride, handling, braking and tire wear characteristics.

So in answer to your question - regardless of what tire and wheel combination that you chose to run, the vehicle's stated recommended tire pressure is the guideline that you should follow.

That said - remember that tire pressures fluctuate based on the heat absorbed from the road surface as well as the friction that is created by the rolling tire. So summer ambient temperatures, plus road surface temperatures will increase actual tire air pressure more that it will on cold weather.

Personally - I like to run my tires 31-32 lbs year around. So in the summer, I run my cold TP around 27 lbs, and in the winter I run them around 29 lbs.

If you have ever watched a NASCAR race - the crew chiefs have someone devoted to measuring the tire pressure and tire temperature, because handling characteristics change with fluctuating pressures and temperatures. Races can be won or lost by monitoring tire pressure to maximize tire wear. Well - it's true of street tires as well. If attention is paid to tire pressure, tire longevity is the payoff. And, as expensive as tires for a Corvette can be, there is absolutely a benefit to paying attention to this, not to mention that the car can ride, handle and brake better too.

Former CF Member Evil-Twin must be credited with this information, I learned it from him. If you're watching.....thanks, Bill!

 

BINGO!

 

...Evil-Twin was right on the money with this one...he said 30-31 hot and that means 26-27 cold(in the summer or depending on where you live and adjustment for the winter or cooler ambient temps)....sounds strange but it is the absolute truth about C5 tires...30 cold could mean 34-37 hot(in the summer), depending on the ambient temperature and thats too much...unless you enjoy seeing the centers wear like crazy

 

When I still had the OEM tires, I would fill to 30 psi cold. The center of each tire would wear faster than the inner and outer areas. I then started to make sure that when hot, no tire pressure exceeded 31 or 32 psi. This seems to be working very well.

 

I fill to 30 lbs cold summer or winter. No unusual tire wear due to pressure. I do get some cornering wear on outside edges of the front tires but the rears wear evenly. GM recommends the cold pressure since that is the one that can be monitored correctly and is correct for all seasons. Street tires just do not get very hot under normal operating conditions. Just put your hand on the tread of a street tire driven at 75 mph for 2 hours and then put your hand on a race tire driven at the limit for a half an hour. You will be able to touch one and not the other. Keeping the cold pressure lower in the summer just generates more heat in the tire which increases pressure more. Tire pressure changes about 1 lb for each 10 degrees of atmospheric temperature. So if you fill your tires to 30 lbs cold when the air temp is 60 and then check them after they soak in an air temp of 80 they will read about 2 lbs higher. The cold temp reading of 30 when temps are 80 will read 28 when the temps drop to 60. GM did a lot of testing to find out the best cold temp setting for all seasons that will give the best combination of performance, endurance and safety.

Bill

 

with you 100% Bill. If that's what the experts at GM recommend, that's good enough for me. Why try to second-guess their expertise? Besides, hasn't it been suggested by some here that we follow GM's recommendations, for example, using the OLM in determining when to change the oil and filter?

 

With all due respect, I see nowhere in the above explaination any consideration for the pavement temperature that also effects tire pressure. Aspahlt gets to 140-150 in the summer months and raises the tire pressure in addition to the ambient air temperature. Thats why just going by air temperature is not good enough and should be adjusted for when considering how much pressure the tires should be at cold or hot. GM gives generic estimates on the door for tire pressure....Evil-Twin was a GM engineer for 30+ years and he definately know what he is talking about especially when talking about tire pressures.

FYI Ever since I started doing what Evil-Twin has suggested...I have seen no abnormal tire wear and better gas milage...
Feel free to choose which method is best for you

 

Forgive me for asking but how do you get better gas mileage by inflating your tires with less psi than what's recommended? That doesn't make any sense to me.

 

GM quoted the recommended tire pressure for the standard tires issued with the car - usually Goodyear Run Flats. However, tire technology changes and many Corvettes are using non - runflats, ala Z-06, and aftermarket runflats and non-runflats. I am using Firestone Wide Ovals -non runflats- and found that I improved handling and ride considerably by adjusting TP up a bit. I started at 30, went up a pound until 34 pounds and then backed down in 1/2 pound intervals until I settled on 32 1/2 pounds as the best compromise for ride and handling in general use. I have not needed to adjust for track or dragstrip, but expect that TP's would need to be played with for both those environments.

As far as the measurment itself, my TP guage is digital - actually, I have two that are digital and the readability is +- 1/2 pound. I won't discuss accuracy as that is a whole subject unto itself. My primary guage matches up with the DIC almost exactly which provides me with good assesment of my set pressures and enables me to add air as needed and maintain my handling characteristics.

So, the designer may have worked closely with the tire vendor for the nameplate guidelines, but each of us needs to be aware and adjust TP's that fit our car, tires, and driving environemen. Its not a sophistiicated thought process, just simple common sense.