Tire pressure
02-17-2018, 02:41 PM
#1
Cruising
Thread Starter
Tire pressure
I looked at the owner manual and said:
FRONT L34 R33 PSI
REAR L34 R33 PSI
Is that means that the left front and rear are 34psi and the right front and rear are 33psi.??
do I really need one psi different..??
Please respond.
Mike
FRONT L34 R33 PSI
REAR L34 R33 PSI
Is that means that the left front and rear are 34psi and the right front and rear are 33psi.??
do I really need one psi different..??
Please respond.
Mike
02-17-2018, 03:09 PM
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02-17-2018, 03:49 PM
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2022 C5 of the Year Finalist - Modified
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What year Vette is this for, Mike?
This is totally different from my '99; for that year, the owners manual only referred me to the door sticker which shows 30# front and rear with no side to side difference.
This is totally different from my '99; for that year, the owners manual only referred me to the door sticker which shows 30# front and rear with no side to side difference.
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02-17-2018, 05:44 PM
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Your profile shows you have a '99 C5. The sticker on the door jamb should say the recommended tire pressures are 30 psi cold on all four tires. That is what I have always run in my car and my tires wear even all the way around.
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Micheluccio (02-17-2018)
02-17-2018, 05:54 PM
#7
Racer
The manual page you're referring to is showing examples only of readouts, not the recommended tire pressure. Read the pressures on the driver door jamb. My '02 says 30 psi for all tires.
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Micheluccio (02-17-2018)
02-17-2018, 06:44 PM
#8
Le Mans Master
Another door jamb readout; 04Z = 30PSI all corners.
I like to experiment... findings? 30PSI works for me.
I like to experiment... findings? 30PSI works for me.
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Micheluccio (02-17-2018)
02-17-2018, 08:51 PM
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St. Jude Donor '11
heres where I got my 30 lb hot answer from over a decade ago...its a long explanation but worth reading and I still go by what he said...best tire pressure info I ever read...
Originally Posted by Evil-Twin
Ive posted this at least 200 times. That sticker on the Door is a DOT compliance sticker.. it's designed to keep people from inflating their tires to 63 psi as it says on the sidewall of the tire.. Tires are not made for specific cars, they are made for specific sizes, therefore, the weight bareing load is different based on the car and its weight. While many people read that as a cold tire pressure, summer or winter .. it is not accurate. 30 cold means nothing because the tire is not in work mode.. Therefore it's not at operating temperature. What you have to do is keep the tire in the sweet spot... 30 psi is the right tire pressure for a 3200 lb vehicle. However, inflating a tire to 30 when they are col dmeans nothing.. Its when they are actually rolling..... take for example, a cool morning test in you garage might yield a 30 psi tire pressdure.. but take that tire out on the road and by noon on a hot day 90+ and on a black top road, the surface temperure of that road can see 160 degree F. NOw that 30 psi tire is at 38 psi.. which will make the tire over pressured for a 3200 lb car. making the footprint ( contact patch ) become center high , reducing the contact patch, wearing the center out of thew tire and reducing the traction and performance and fuel economy..
IN the summer.. there is a big swing in ambient temperature, as much as 40 degrees in 24 hours..
So after giving you all of this information. it is fairly easy to see where your tire pressure should be. For me, in the summer I set my tires to 26/28 psi. this will insure that my tires do not get over pressured by mid day. You don't have to adjust the pressure daily or weekly or even monthly.. but between June and August, you want light pressure cold (26/28 psi ) this will put them in the sweet spot, and give you the best performance and insure against premature center wear. On a really hot day 90+ and you are out and about.. check with the DIC and see if your tires are where they should be.. if they are north of 34 or 35 psi, drop a few pound to get you to 30/31 psi. That should be your set point. check once a month, because 02 escapes through the side wall ( more in the summer ) . Winter time, tire pressure become lower because the air is more dense , so you may have to add tire pressure in the winter because with O2 loss and cold temps you don't want to be running around on 26 psi, you may even get a low tire warning in the winter, and need to pump up the pressure.. This is what I call tire tuning for best performance and tire longevity..
This is how all Indy, and Nascar events are monitored by pit crews. They monitor track condition and track temperature to insure proper tire pressure so they can get that extra two laps out of a tire, and those extra miles of fuel consumption. Races are won or lost on improper tire pressure. Proper tire pressure tuning is good for your cars performance and also for its fuel economy.. and of course your wallet.. understand tire pressure and it will greatly benefit your Corvette experience. BTW just 1 or 2 psi can make a big difference. That extra mile to the gallon of fuel, and those extra thousand miles to a set of tires.
POST #189 on this subject.
Happy summer
Bill aka ET
So Keep it in the sweet spot. ( 30/31 psi Hot )
IN the summer.. there is a big swing in ambient temperature, as much as 40 degrees in 24 hours..
So after giving you all of this information. it is fairly easy to see where your tire pressure should be. For me, in the summer I set my tires to 26/28 psi. this will insure that my tires do not get over pressured by mid day. You don't have to adjust the pressure daily or weekly or even monthly.. but between June and August, you want light pressure cold (26/28 psi ) this will put them in the sweet spot, and give you the best performance and insure against premature center wear. On a really hot day 90+ and you are out and about.. check with the DIC and see if your tires are where they should be.. if they are north of 34 or 35 psi, drop a few pound to get you to 30/31 psi. That should be your set point. check once a month, because 02 escapes through the side wall ( more in the summer ) . Winter time, tire pressure become lower because the air is more dense , so you may have to add tire pressure in the winter because with O2 loss and cold temps you don't want to be running around on 26 psi, you may even get a low tire warning in the winter, and need to pump up the pressure.. This is what I call tire tuning for best performance and tire longevity..
This is how all Indy, and Nascar events are monitored by pit crews. They monitor track condition and track temperature to insure proper tire pressure so they can get that extra two laps out of a tire, and those extra miles of fuel consumption. Races are won or lost on improper tire pressure. Proper tire pressure tuning is good for your cars performance and also for its fuel economy.. and of course your wallet.. understand tire pressure and it will greatly benefit your Corvette experience. BTW just 1 or 2 psi can make a big difference. That extra mile to the gallon of fuel, and those extra thousand miles to a set of tires.
POST #189 on this subject.
Happy summer
Bill aka ET
So Keep it in the sweet spot. ( 30/31 psi Hot )
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Micheluccio (02-17-2018)
02-18-2018, 12:55 PM
#10
Drifting
O2 does not escape through the sidewall of the tire. Just because ET says that you believe it? Show me the evidence of that instead of just spouting that out.
The tire pressure drop over time is from air leaking out via the tire stem or at the rim seal, not from diffusion through the rubber. If that were the case, it would be very simple to analyze the air left inside the tire after sitting for a long while and show the % of O2 had dropped and the % of N2 rose. Can you show even one study that proves that?
And that tire pressure on the tag in the doorwell is a recommendation based on a combo of factors- softness and comfort of the ride, performance, longevity, etc.- and is not set in stone as an absolute. It is also a COLD pressure recommendation. GM, or anyone else, does not expect you to get out of your car after driving on the highway at speed for hours and expect you to measure and adjust the tire pressures during your trip.
People should not promote bullshit, there's enough of it going around.
And FWIW, I keep the tire pressures in all my cars ~32 cold and like the ride better and have no problem with wear or longevity, and it probably gives me an extra mpg or two in economy which doesn't really matter in all of this.
The tire pressure drop over time is from air leaking out via the tire stem or at the rim seal, not from diffusion through the rubber. If that were the case, it would be very simple to analyze the air left inside the tire after sitting for a long while and show the % of O2 had dropped and the % of N2 rose. Can you show even one study that proves that?
And that tire pressure on the tag in the doorwell is a recommendation based on a combo of factors- softness and comfort of the ride, performance, longevity, etc.- and is not set in stone as an absolute. It is also a COLD pressure recommendation. GM, or anyone else, does not expect you to get out of your car after driving on the highway at speed for hours and expect you to measure and adjust the tire pressures during your trip.
People should not promote bullshit, there's enough of it going around.
And FWIW, I keep the tire pressures in all my cars ~32 cold and like the ride better and have no problem with wear or longevity, and it probably gives me an extra mpg or two in economy which doesn't really matter in all of this.
02-18-2018, 01:08 PM
#11
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02-18-2018, 01:26 PM
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St. Jude Donor '11
O2 does not escape through the sidewall of the tire. Just because ET says that you believe it?[COLOR="Red"] Show me the evidence of that instead of just spouting that out[/COLOR].
The tire pressure drop over time is from air leaking out via the tire stem or at the rim seal, not from diffusion through the rubber. If that were the case, it would be very simple to analyze the air left inside the tire after sitting for a long while and show the % of O2 had dropped and the % of N2 rose. Can you show even one study that proves that?
And that tire pressure on the tag in the doorwell is a recommendation based on a combo of factors- softness and comfort of the ride, performance, longevity, etc.- and is not set in stone as an absolute. It is also a COLD pressure recommendation. GM, or anyone else, does not expect you to get out of your car after driving on the highway at speed for hours and expect you to measure and adjust the tire pressures during your trip.
People should not promote bullshit, there's enough of it going around.
And FWIW, I keep the tire pressures in all my cars ~32 cold and like the ride better and have no problem with wear or longevity, and it probably gives me an extra mpg or two in economy which doesn't really matter in all of this.
The tire pressure drop over time is from air leaking out via the tire stem or at the rim seal, not from diffusion through the rubber. If that were the case, it would be very simple to analyze the air left inside the tire after sitting for a long while and show the % of O2 had dropped and the % of N2 rose. Can you show even one study that proves that?
And that tire pressure on the tag in the doorwell is a recommendation based on a combo of factors- softness and comfort of the ride, performance, longevity, etc.- and is not set in stone as an absolute. It is also a COLD pressure recommendation. GM, or anyone else, does not expect you to get out of your car after driving on the highway at speed for hours and expect you to measure and adjust the tire pressures during your trip.
People should not promote bullshit, there's enough of it going around.
And FWIW, I keep the tire pressures in all my cars ~32 cold and like the ride better and have no problem with wear or longevity, and it probably gives me an extra mpg or two in economy which doesn't really matter in all of this.
Sir...that is ETs info...I didn't spout it out....his info has worked for me personally for 10+ years...also...I know lots of people love ET and lots hate him....I do not communicate with him anymore since we got a divorce a while back
...no matter what, I still respect his knowledge even if I disagree with his "beliefs"...if you knew him as I have for over 10+ years you would understand that he is a Teddy Bear at heart...but can be a MF sometimes because of all of the meds he takes....we fought over simple crap which I shouldn't have done...I lost a dear friend......
But again sir...it is my belief that his information is dead on correct...just my opinion...
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c5arlen (02-19-2018)
02-18-2018, 06:58 PM
#13
Le Mans Master
And again, that door jamb tire pressure is for runflats.
add 5 PSI for conventional tires
add 5 PSI for conventional tires
Last edited by coupeguy2001; 02-18-2018 at 06:59 PM.
02-19-2018, 11:26 AM
#15
Drifting
Yellow95 - My 32 cold NEVER gets up to 38-40 in the summer, maybe gets to 35-36 on a long 80 mph highway drive, which is perfectly acceptable and anticipated, so that statement is wrong. I do adjust it summer and winter and it is always between 30-32 COLD when I start out and it's one of the things I check when I start out on a drive.
I'm not **** enough, it the car has been sitting out in the sun, to go out and adjust the pressure if it rose due to the heat of the sun, but it sounds like some of you might do that.
I'm not **** enough, it the car has been sitting out in the sun, to go out and adjust the pressure if it rose due to the heat of the sun, but it sounds like some of you might do that.
02-19-2018, 12:48 PM
#16
Corvette C5 Enthusiast
Good info from ET, which I've followed. You can see where it makes a lot of sense, especially when you are rolling in hot weather on super hot asphalt.
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Yello95 (02-19-2018)
02-19-2018, 02:35 PM
#17
Look at the sidewalls of your tires, not what GM says on the door tag. If you run the same exact tire that GM put on the car in the beginning, then fine, look at the GM tag.
I have a lot of different cars/trucks/trailers. I go by the sidewall on all of them.
When I am not towing, my truck tries are at 60psi. When I am towing, they are at 80psi.
I actually do check tire pressure after driving to see what they are up to when they get hot and adjust from there.
I have a lot of different cars/trucks/trailers. I go by the sidewall on all of them.
When I am not towing, my truck tries are at 60psi. When I am towing, they are at 80psi.
I actually do check tire pressure after driving to see what they are up to when they get hot and adjust from there.
02-19-2018, 04:15 PM
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St. Jude Donor '11
" the principle is called Graham's law.. a well known engineering and scientific principle.. also At GM we have always called that DOT sticker on the door " Idiot Proofing " Since it only keep people out of trouble, people who max out tire pressure based on Max sidewall psi printed on it."
.."..for that nay sayer or should I say the object of our idiot proofing....
Graham’s Law:
Are Nitrogen Molecules Really Larger Than Oxygen Molecules? The correct answer, with respect to “permeation”, is yes. "
"There's often confusion associated with the molecular size, molecular weight and permeation properties of oxygen and nitrogen molecules, and GNI is often called to task to explain why nitrogen actually migrates (permeates) out through the rubber of a tire slower than does oxygen but at a much higher rate. both molecules exit through the rubber sidewall .. But the O2 exits much faster.. since air consists of oxygen and Nitrogen. The reason people put pure nitrogen in their tires is because the molecules are larger and there is less swing in the loss of tire pressure.
"
"So for the guy saying BS.. let's see his engineering degree.. or any fact based on his lack of automotive knowledge based on any scientific principles or laws. and also, that door sticker for people just like him. "
"Fine tuning tires is what every race team in the world does. It separates professionals from amateurs who think they know something about automotive technology."
"Since air is made up of 78% nitrogen, 21% oxygen 1% argon and trace amounts of carbon dioxide, the potential of a dry sidewall allowing the small O2 molecule to escape is very relevant. So says Graham's law.. a scientific principle Not BS."
Last edited by Yello95; 02-21-2018 at 01:22 AM.
02-20-2018, 01:07 PM
#19
Look at the sidewalls of your tires, not what GM says on the door tag. If you run the same exact tire that GM put on the car in the beginning, then fine, look at the GM tag.
I have a lot of different cars/trucks/trailers. I go by the sidewall on all of them.
When I am not towing, my truck tries are at 60psi. When I am towing, they are at 80psi.
I actually do check tire pressure after driving to see what they are up to when they get hot and adjust from there.
I have a lot of different cars/trucks/trailers. I go by the sidewall on all of them.
When I am not towing, my truck tries are at 60psi. When I am towing, they are at 80psi.
I actually do check tire pressure after driving to see what they are up to when they get hot and adjust from there.
02-20-2018, 04:48 PM
#20
Melting Slicks
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Look at the sidewalls of your tires, not what GM says on the door tag. If you run the same exact tire that GM put on the car in the beginning, then fine, look at the GM tag.
I have a lot of different cars/trucks/trailers. I go by the sidewall on all of them.
When I am not towing, my truck tries are at 60psi. When I am towing, they are at 80psi.
I actually do check tire pressure after driving to see what they are up to when they get hot and adjust from there.
I have a lot of different cars/trucks/trailers. I go by the sidewall on all of them.
When I am not towing, my truck tries are at 60psi. When I am towing, they are at 80psi.
I actually do check tire pressure after driving to see what they are up to when they get hot and adjust from there.
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C6_Racer_X (02-21-2018)