taildragger so you claim to be the troll of the month?
Fill Tire Pressure To What Tire or Vehicle Says?
- Thread starter crazyoildude
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Originally Posted By: crazyoildude
i totally disagree the tire business done correctly is very very profitable,
Says the one who doesn't even know what the proper tire inflation should be.
i totally disagree the tire business done correctly is very very profitable,
Says the one who doesn't even know what the proper tire inflation should be.
like i said in previous posts im in the engine business and not a tire expert but before you say anything else wait there was a reason for this post.
IMO, the correct answer is a combination of the two numbers-for instance, on the Cherokee in my sig I have slightly oversize tires, 235/75R15 Geolandars, that are rated 50 PSI max. The tire placard for the OEM 225s suggest 33 PSI on both axles-but the fronts wear heavily on the shoulders (as do most solid axle 4X4s) & squeal on turns at that pressure. So I have 40 in the front & 35 in the rears, works fine-& if I pull the utility trailer the rears are 50.
if you're in the engine business or any car related enterprise, I hope you at least got an ASE or other certification.
But to get even the very first entry level certification you need a minimal amount of coursework about the how a whole car works and is maintained, including chassis/tire stuff. A single course covers all of this and it's not super high level.
So saying you're in an engine business doesn't make you look good, it actually makes it look worse on you are working on a crucial car system but lack the knowledge of how an entire car works at even a general certification level.
It would be like a plastic surgeon touting that he's a plastic surgeon, but does not know what are the organs in the body and their general functions.
But to get even the very first entry level certification you need a minimal amount of coursework about the how a whole car works and is maintained, including chassis/tire stuff. A single course covers all of this and it's not super high level.
So saying you're in an engine business doesn't make you look good, it actually makes it look worse on you are working on a crucial car system but lack the knowledge of how an entire car works at even a general certification level.
It would be like a plastic surgeon touting that he's a plastic surgeon, but does not know what are the organs in the body and their general functions.
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Running "H" rated 205/60R15's on a car that had 185/65R15's
Max pressure of OEM's was 35, now is 51...
I put 47 in, if you have loose fillings in your teeth your in trouble...
But the tire wear and mileage is great..
Door is for ride comfort, if your not running the size on the door, or want better wear and mileage, add PSI up to near the tire max when cold...
Max pressure of OEM's was 35, now is 51...
I put 47 in, if you have loose fillings in your teeth your in trouble...
But the tire wear and mileage is great..
Door is for ride comfort, if your not running the size on the door, or want better wear and mileage, add PSI up to near the tire max when cold...
Its personal preference. My Buick says 24 lbs I say nope.
35 pounds cold and still have a quality ride.
I don't know what GM was thinking when they said 24 lbs...
35 pounds cold and still have a quality ride.
I don't know what GM was thinking when they said 24 lbs...
My last two vehicles (the only two I've been diligent about) got increased center wear running over the factory recommendations on pressure. So, I don't do that anymore. Maybe a couple PSI over, but no more than that.
As noted many times, you run the door placard pressure. In my truck, the sticker is actually in the glove box, not on the door pillar.
As noted many times, you run the door placard pressure. In my truck, the sticker is actually in the glove box, not on the door pillar.
This is my point i was trying to make everyone has a different way of looking at this and everyone has their own beliefs. Someone posted tire shops putting all different pressures into tires i personally believe if you have an old car in the early 90's and it specs 35psi on the door and you put tires that say for instance max.50psi it is absolutely ok to put 40psi in them when cold. tires have improved a lot since the 1990 era. When i put 35 psi in my old truck it drove like a Cadillac but my tires wore and being underpowered it would lug going up hills with a heavy load when i put 40psi it was much better in every way. But the real reason i brought this subject up was to see some peoples beliefs some don't agree with me and some do but how many vehicles are driving on the road with who knows what in their tires. I know my new car dealer puts in the maximum the tires allow and i have to adjust them when i get home.
From TireRack :
Air Pressure: When and How to Set:
Maintenance Tips to Increase Tire Performance, Life and Durability
Check and adjust first thing in the morning. Set according to the vehicle manufacturer's cold tire pressure(s) recommended on the vehicle's tire placard or in its owner's manual. This must be done before rising ambient temperatures, the sun's radiant heat or even driving short distances temporarily warms the tires.
Accommodating Variables
Indoor-to-outdoor Temperature Variation. Significant differences between the conditions tire pressures are set (the warmth of an attached garage, heated garage or service shop) and in which the vehicle will be driven (winter's subfreezing temperatures) requires inflating tires 1 psi higher than recommended on the placard for every 10° F difference in temperature between interior and exterior temperatures.
Afternoon Ambient Temperature Increase.* Set 2 psi above vehicle manufacturer's cold inflation recommendations when installing new tires or if the vehicle has been parked in the shade for a few hours.
Tire Heat Generated While Being Driven (or at speeds of less than 45 mph).* - Set 4 psi above vehicle manufacturer's cold inflation recommendations.
Heat Generated While Being Driven Extensively (or at sustained speeds greater than 45 mph).* Set 6 psi above vehicle manufacturer's cold inflation recommendations.
Do Not Release Hot Tire Pressure if any of these variables could be the cause of measured tire pressure exceeding the maximum psi branded on the tire's sidewall by the 2, 4 or 6 psi indicated above for the various conditions. This temporary pressure increase is expected and designed into the tire's capabilities.
*NOTE: Tires on a parked vehicle exposed to direct sunlight will appear overinflated due to the heat absorbed from the radiant energy of the sun. Pressures cannot be accurately set on these tires until all have stabilized in the shade.
Air Pressure: When and How to Set:
Maintenance Tips to Increase Tire Performance, Life and Durability
Check and adjust first thing in the morning. Set according to the vehicle manufacturer's cold tire pressure(s) recommended on the vehicle's tire placard or in its owner's manual. This must be done before rising ambient temperatures, the sun's radiant heat or even driving short distances temporarily warms the tires.
Accommodating Variables
Indoor-to-outdoor Temperature Variation. Significant differences between the conditions tire pressures are set (the warmth of an attached garage, heated garage or service shop) and in which the vehicle will be driven (winter's subfreezing temperatures) requires inflating tires 1 psi higher than recommended on the placard for every 10° F difference in temperature between interior and exterior temperatures.
Afternoon Ambient Temperature Increase.* Set 2 psi above vehicle manufacturer's cold inflation recommendations when installing new tires or if the vehicle has been parked in the shade for a few hours.
Tire Heat Generated While Being Driven (or at speeds of less than 45 mph).* - Set 4 psi above vehicle manufacturer's cold inflation recommendations.
Heat Generated While Being Driven Extensively (or at sustained speeds greater than 45 mph).* Set 6 psi above vehicle manufacturer's cold inflation recommendations.
Do Not Release Hot Tire Pressure if any of these variables could be the cause of measured tire pressure exceeding the maximum psi branded on the tire's sidewall by the 2, 4 or 6 psi indicated above for the various conditions. This temporary pressure increase is expected and designed into the tire's capabilities.
*NOTE: Tires on a parked vehicle exposed to direct sunlight will appear overinflated due to the heat absorbed from the radiant energy of the sun. Pressures cannot be accurately set on these tires until all have stabilized in the shade.
Originally Posted By: crazyoildude
This is my point i was trying to make everyone has a different way of looking at this and everyone has their own beliefs.
It's not about beliefs. The car/tire industry is pretty clear on which PSI value to use, and it is NOT the number you see printed on the tire.
Quote:
some don't agree with me and some do
I'm looking at the responses, and I don't see a single person that agreed with you to run the pressure that's listed on the tire.
This is my point i was trying to make everyone has a different way of looking at this and everyone has their own beliefs.
It's not about beliefs. The car/tire industry is pretty clear on which PSI value to use, and it is NOT the number you see printed on the tire.
Quote:
some don't agree with me and some do
I'm looking at the responses, and I don't see a single person that agreed with you to run the pressure that's listed on the tire.
Wow. Everything single thing the OP said was wrong. Door tag is usually what it should be unless load ratings are changed. In that case pressure can be adjusted based off of load tables. Pressure should be set cold. Even if you were to set it to max psi cold, the tires are designed to compensate for temperature related pressure changes. 35psi cold usually end a up being about 39psi hot. Set it to 35psi hot and your pressure drops to 31 cold. Now they are under inflated.
I can't believe how much misinformation is being spread out there...smh...
I can't believe how much misinformation is being spread out there...smh...
raytseng,
i see you are a software guy and im sure in your business credentials mean a lot. You mention ase certification and to be honest with you the last 2 people i hired with the best credentials coming out of the best schools were the worst, I have been doing engines for lots and lots of years and my shop which is in the middle of being sold is one of the most respected ones in my state and certainly one of the busiest. We don't do tires just engines but my beliefs in air pressure in tires have gotten me through for many years with one mistake when i was 12 i put air in my bike tire and it blew that is when i learned about tire pressure. HaHa i still remember that popping noise!
i see you are a software guy and im sure in your business credentials mean a lot. You mention ase certification and to be honest with you the last 2 people i hired with the best credentials coming out of the best schools were the worst, I have been doing engines for lots and lots of years and my shop which is in the middle of being sold is one of the most respected ones in my state and certainly one of the busiest. We don't do tires just engines but my beliefs in air pressure in tires have gotten me through for many years with one mistake when i was 12 i put air in my bike tire and it blew that is when i learned about tire pressure. HaHa i still remember that popping noise!
Originally Posted By: Quattro Pete
Originally Posted By: crazyoildude
This is my point i was trying to make everyone has a different way of looking at this and everyone has their own beliefs.
It's not about beliefs. The car/tire industry is pretty clear on which PSI value to use, and it is NOT the number you see printed on the tire.
Quote:
some don't agree with me and some do
I'm looking at the responses, and I don't see a single person that agreed with you to run the pressure that's listed on the tire.
Agreed Pete.
Originally Posted By: crazyoildude
This is my point i was trying to make everyone has a different way of looking at this and everyone has their own beliefs.
It's not about beliefs. The car/tire industry is pretty clear on which PSI value to use, and it is NOT the number you see printed on the tire.
Quote:
some don't agree with me and some do
I'm looking at the responses, and I don't see a single person that agreed with you to run the pressure that's listed on the tire.
Agreed Pete.
Fill it with what's on the door.
The pressure on your tire is the maximum allowable pressure to be used with the maximum rated load. Too high of pressure relative to the weight you have on the tire will result in a stiffer ride and uneven wear on the tire - the tread will bulge somewhat and the center will wear more than the sides
The pressure on your tire is the maximum allowable pressure to be used with the maximum rated load. Too high of pressure relative to the weight you have on the tire will result in a stiffer ride and uneven wear on the tire - the tread will bulge somewhat and the center will wear more than the sides
Crazyoildude gone crazy. Sure you can fill a tire to what ever pressure floats your boat and I'm sure it will work fine, but the best ride and performance will be had by filling it to the specs on the door. I know you don't do tires but it is still shocking that anyone working on anything car related would suggest otherwise.
The laws of physics hasn't really changed since the 90's. Basically the only one who really knows how the car will handle is the car manufacturer. The tire maker has no idea what car the tire is going on so it can only recommend the max inflation pressure. The pressure listed on the car is the recommended pressure for that car. Anything different can affect wear and handling. I'm not really sure why it's that difficult to comprehend this, this is basically what everyone else is saying. It's the car manufacturer that knows what suspension components were used and did the testing on the car.
Originally Posted By: Wolf359
The laws of physics hasn't really changed since the 90's. Basically the only one who really knows how the car will handle is the car manufacturer. The tire maker has no idea what car the tire is going on so it can only recommend the max inflation pressure. The pressure listed on the car is the recommended pressure for that car. Anything different can affect wear and handling. I'm not really sure why it's that difficult to comprehend this, this is basically what everyone else is saying. It's the car manufacturer that knows what suspension components were used and did the testing on the car.
I think of the door jamb numbers as a starting point.
The main issue is that one important component is different most of the time, and that would be aftermarket tires. They might have a different contact patch or different characteristics than the OEM tires. Those aren't some sort of magic number. They're a compromise between ride comfort, fuel economy, and wear - as several have stated. Quite a few have tried higher-performance aftermarket tires and found that they needed a little more pressure than OEM. Also - driving style may affect the optimal pressure. There really is no optimal pressure for every driver, every way a car is loaded, and every tire. The numbers the manufacturer puts down are more or less "yeah - this will be acceptable for most drivers without making them think too hard about it".
Here's a suggesting for how to pick an optimal pressure for aftermarket tires. The technique involves using chalk and having a short test drive to see where the chalk wears off.
http://howards.hubpages.com/hub/Checking-Tire-Pressures-Aftermarket-Wheels
Ford supposedly had a number that some owners took as ideal for the 90s Explorer. Until tires started blowing up and people started dying. In that case they were compromising fuel economy for ride comfort - or at least that's what they thought.
The laws of physics hasn't really changed since the 90's. Basically the only one who really knows how the car will handle is the car manufacturer. The tire maker has no idea what car the tire is going on so it can only recommend the max inflation pressure. The pressure listed on the car is the recommended pressure for that car. Anything different can affect wear and handling. I'm not really sure why it's that difficult to comprehend this, this is basically what everyone else is saying. It's the car manufacturer that knows what suspension components were used and did the testing on the car.
I think of the door jamb numbers as a starting point.
The main issue is that one important component is different most of the time, and that would be aftermarket tires. They might have a different contact patch or different characteristics than the OEM tires. Those aren't some sort of magic number. They're a compromise between ride comfort, fuel economy, and wear - as several have stated. Quite a few have tried higher-performance aftermarket tires and found that they needed a little more pressure than OEM. Also - driving style may affect the optimal pressure. There really is no optimal pressure for every driver, every way a car is loaded, and every tire. The numbers the manufacturer puts down are more or less "yeah - this will be acceptable for most drivers without making them think too hard about it".
Here's a suggesting for how to pick an optimal pressure for aftermarket tires. The technique involves using chalk and having a short test drive to see where the chalk wears off.
http://howards.hubpages.com/hub/Checking-Tire-Pressures-Aftermarket-Wheels
Ford supposedly had a number that some owners took as ideal for the 90s Explorer. Until tires started blowing up and people started dying. In that case they were compromising fuel economy for ride comfort - or at least that's what they thought.
Don't forget to consider what were the circumstances of the Original Posted Situation. "A friend of mine asked me...".
Do whatever you want with your own car and your own life; but if you're asked by someone else, the only advice you should be give is to parrot back what is in the manual.
Do whatever you want with your own car and your own life; but if you're asked by someone else, the only advice you should be give is to parrot back what is in the manual.
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