I always run 2-3 above the door panel recommendation during the spring and fall, slightly more than that during the winter. But during the summer I usually shoot for exactly what's on the door panel. My thinking is that there is less temperature variation at night during the summer so the tires aren't going through those heating and cooling cycles that cause you to lose pressure. And the tires heat up more when you're driving so you're that little bit over the recommended pressure once you start driving. Thoughts?
Make sense to run a little lower pressure summer?
- Thread starter teddyboy
- Start date
- Status
My car calls for 32/30 (F/R) and I was running 40/38 for a while, but recently reduced to 36/34 now that the tire was reaching the end of its life and ride was getting a bit harsh. My new tires will be mounted in the next week or so, and plan to run them around 36/34 or 38/36 depending on feel.
I use the same pressure year-round. My winter tires I run at 34/32 I believe, just above the recommended. (Max is 44psi).
I use the same pressure year-round. My winter tires I run at 34/32 I believe, just above the recommended. (Max is 44psi).
Every tire/car combo seems to have its sweet spot. I was running 2psig over the sticker on my new truck (as delivered)and the tires were bouncing off the road and riding like rocks in the hot 90 degree afternoon commute. Brought the pressure back into line and all was well. If running an unfamiliar tire combo or oversize, I'll start ~2psig UNDER the spec and work up (tires dont like to be deflated hot, I'll tell you that). To exhibit the contact patch, a shade tree trick is to: drive through a thin layer of sand on the road with a wet tire, then look at what the sand "painted"; next, make sure its not wrapping around the sidewall(underinflated) or riding on the centre tread only(overinflated). Note: Heavily loading any vehicle to full GVWR requires pressure adjustment upwards from something that is a driver only commuter.
Last edited:
Originally Posted By: teddyboy
I always run 2-3 above the door panel recommendation during the spring and fall, slightly more than that during the winter. But during the summer I usually shoot for exactly what's on the door panel. My thinking is that there is less temperature variation at night during the summer so the tires aren't going through those heating and cooling cycles that cause you to lose pressure. And the tires heat up more when you're driving so you're that little bit over the recommended pressure once you start driving. Thoughts?
What your doing is adjusting your cold tire temps seasonally to have a consistent operating pressure all year round. Probably a good idea I guess. The rule of thumb I've read is that for every 10F increase tire temp, the pressure goes up 1 psi. So I guess if you want 32 psi driving 75 mph on a hot sunny day when your tires are 120F, you would inflate your tires to maybe 27psi when the tire is at 70F. I wouldn't recommend that though as the penalties of running a few psi to low seem to be much greater than a few psi to high.
I always run 2-3 above the door panel recommendation during the spring and fall, slightly more than that during the winter. But during the summer I usually shoot for exactly what's on the door panel. My thinking is that there is less temperature variation at night during the summer so the tires aren't going through those heating and cooling cycles that cause you to lose pressure. And the tires heat up more when you're driving so you're that little bit over the recommended pressure once you start driving. Thoughts?
What your doing is adjusting your cold tire temps seasonally to have a consistent operating pressure all year round. Probably a good idea I guess. The rule of thumb I've read is that for every 10F increase tire temp, the pressure goes up 1 psi. So I guess if you want 32 psi driving 75 mph on a hot sunny day when your tires are 120F, you would inflate your tires to maybe 27psi when the tire is at 70F. I wouldn't recommend that though as the penalties of running a few psi to low seem to be much greater than a few psi to high.
Teddy, I think your strategy is just fine. In the fall, when temps (and hence pressures) are dropping, it is a good idea to keep a couple of pounds ahead of the game. In summer, I run the spec'd psi except for family trips I put a couple extra pounds back in.
I also believe it's OK to use a 2 pound range differential between front and rear to address understeer in a sporting vehicle.
I also believe it's OK to use a 2 pound range differential between front and rear to address understeer in a sporting vehicle.
Last edited:
They think that "little bit over cold pressure" thing when they spec the cold pressure.
I would ask, in which season do your tires wear out the fastest? What wears them out, and how would you protect them?
This is not a snarky question, I just want to get you thinking.
Also the wide temperature extremes don't make tires leak. They rise and fall in pressure, but nothing unusual gets out.
I've seen recommendations for tires to be pumped up a few extra PSI (35 instead of 32) when driving for sustained high speeds. Which cause heat. Which you get more of in the summer.
I would ask, in which season do your tires wear out the fastest? What wears them out, and how would you protect them?
This is not a snarky question, I just want to get you thinking.
Also the wide temperature extremes don't make tires leak. They rise and fall in pressure, but nothing unusual gets out.
I've seen recommendations for tires to be pumped up a few extra PSI (35 instead of 32) when driving for sustained high speeds. Which cause heat. Which you get more of in the summer.
Originally Posted By: teddyboy
I always run 2-3 above the door panel recommendation during the spring and fall, slightly more than that during the winter. But during the summer I usually shoot for exactly what's on the door panel. My thinking is that there is less temperature variation at night during the summer so the tires aren't going through those heating and cooling cycles that cause you to lose pressure. And the tires heat up more when you're driving so you're that little bit over the recommended pressure once you start driving. Thoughts?
No, that's is 100% the wrong direction!
Heat is the tire killer! You want to minimize the amount of heat a tire experiences. You can't do anything about the ambient temperature, but you can do something about how much buildup there is - by adding more pressure to start with.
I always run 2-3 above the door panel recommendation during the spring and fall, slightly more than that during the winter. But during the summer I usually shoot for exactly what's on the door panel. My thinking is that there is less temperature variation at night during the summer so the tires aren't going through those heating and cooling cycles that cause you to lose pressure. And the tires heat up more when you're driving so you're that little bit over the recommended pressure once you start driving. Thoughts?
No, that's is 100% the wrong direction!
Heat is the tire killer! You want to minimize the amount of heat a tire experiences. You can't do anything about the ambient temperature, but you can do something about how much buildup there is - by adding more pressure to start with.
First of all, the tire pressures recommended by the manufacturer are cold tire pressures for the load range handled by the OEM tire. (Some models have multiple recommendations based upon the load carried by the vehicle.) Just remember that lower than recommended cold inflation values will increase tire rolling resistance resulting in lower MPG.
Second, checking your tire pressures cold at least once a week with the same tire pressure gauge isn't a bad idea. (You'll find a slow leaker quicker this way.)
Many things affect hot tire pressure, e.g., outside temperature, vehicle weight, sustained high speed (Interstate) driving, etc. For every 10F change in outside temperature, you tire can either gain or loss a pound of pressure. (Park all day with one side of the car facing the sun and the other side in shade, you'll find the side in the sun has the higher tires pressures.) Trying to adjust hot tire pressures rather than cold tire pressures is best left to those that race. They have reams of data that take into account air temp, track temp, track grip, tire grip, etc.
Personally, I run the recommended cold tire pressure all year round (except when autocrossing or during track days). My owner's manual gives me other recommended tire pressures for "softening" a harsh ride (lower cold pressures to allow the tire to absorb some of the bumps) or when enjoying "spirited" driving (higher cold pressures to stiffen the sidewalls to improve transient steering response).
YMMV as to what cold tire pressures work best for your vehicle; but be sure to watch your tire wear, and don't exceed the max inflation PSI stated on your tire's sidewall as a safety precaution.
Second, checking your tire pressures cold at least once a week with the same tire pressure gauge isn't a bad idea. (You'll find a slow leaker quicker this way.)
Many things affect hot tire pressure, e.g., outside temperature, vehicle weight, sustained high speed (Interstate) driving, etc. For every 10F change in outside temperature, you tire can either gain or loss a pound of pressure. (Park all day with one side of the car facing the sun and the other side in shade, you'll find the side in the sun has the higher tires pressures.) Trying to adjust hot tire pressures rather than cold tire pressures is best left to those that race. They have reams of data that take into account air temp, track temp, track grip, tire grip, etc.
Personally, I run the recommended cold tire pressure all year round (except when autocrossing or during track days). My owner's manual gives me other recommended tire pressures for "softening" a harsh ride (lower cold pressures to allow the tire to absorb some of the bumps) or when enjoying "spirited" driving (higher cold pressures to stiffen the sidewalls to improve transient steering response).
YMMV as to what cold tire pressures work best for your vehicle; but be sure to watch your tire wear, and don't exceed the max inflation PSI stated on your tire's sidewall as a safety precaution.
Originally Posted By: CapriRacer
Originally Posted By: teddyboy
I always run 2-3 above the door panel recommendation during the spring and fall, slightly more than that during the winter. But during the summer I usually shoot for exactly what's on the door panel. My thinking is that there is less temperature variation at night during the summer so the tires aren't going through those heating and cooling cycles that cause you to lose pressure. And the tires heat up more when you're driving so you're that little bit over the recommended pressure once you start driving. Thoughts?
No, that's is 100% the wrong direction!
Heat is the tire killer! You want to minimize the amount of heat a tire experiences. You can't do anything about the ambient temperature, but you can do something about how much buildup there is - by adding more pressure to start with.
+1!!
Originally Posted By: teddyboy
I always run 2-3 above the door panel recommendation during the spring and fall, slightly more than that during the winter. But during the summer I usually shoot for exactly what's on the door panel. My thinking is that there is less temperature variation at night during the summer so the tires aren't going through those heating and cooling cycles that cause you to lose pressure. And the tires heat up more when you're driving so you're that little bit over the recommended pressure once you start driving. Thoughts?
No, that's is 100% the wrong direction!
Heat is the tire killer! You want to minimize the amount of heat a tire experiences. You can't do anything about the ambient temperature, but you can do something about how much buildup there is - by adding more pressure to start with.
+1!!
I certainly have a lot to think about now. Thanks for all the input.
Originally Posted By: Astro14
Originally Posted By: CapriRacer
Originally Posted By: teddyboy
I always run 2-3 above the door panel recommendation during the spring and fall, slightly more than that during the winter. But during the summer I usually shoot for exactly what's on the door panel. My thinking is that there is less temperature variation at night during the summer so the tires aren't going through those heating and cooling cycles that cause you to lose pressure. And the tires heat up more when you're driving so you're that little bit over the recommended pressure once you start driving. Thoughts?
No, that's is 100% the wrong direction!
Heat is the tire killer! You want to minimize the amount of heat a tire experiences. You can't do anything about the ambient temperature, but you can do something about how much buildup there is - by adding more pressure to start with.
+1!!
+2
I ran a little higher pressure in summer than in winter, plus 4-6PSI in summer and plus 2-3PSI in winter, all pressures are cold. I know we don't have real winter in So Cal, but on average it's about 15-25F cooler in winter than in summer here.
Originally Posted By: CapriRacer
Originally Posted By: teddyboy
I always run 2-3 above the door panel recommendation during the spring and fall, slightly more than that during the winter. But during the summer I usually shoot for exactly what's on the door panel. My thinking is that there is less temperature variation at night during the summer so the tires aren't going through those heating and cooling cycles that cause you to lose pressure. And the tires heat up more when you're driving so you're that little bit over the recommended pressure once you start driving. Thoughts?
No, that's is 100% the wrong direction!
Heat is the tire killer! You want to minimize the amount of heat a tire experiences. You can't do anything about the ambient temperature, but you can do something about how much buildup there is - by adding more pressure to start with.
+1!!
+2
I ran a little higher pressure in summer than in winter, plus 4-6PSI in summer and plus 2-3PSI in winter, all pressures are cold. I know we don't have real winter in So Cal, but on average it's about 15-25F cooler in winter than in summer here.
While there are basic recommendations for all vehicles, every car and driver is a different animal. The door placard is just for a new stocker with factory rubber. The OPTIMUM pressure for your tire/wheel/auto/driver combo may vary a bit.
But it is a generally accepted rule of thumb that the hotter it gets (ambient temp) then you want more pressure, not less. Get an IR temp sensor gun and take readings at all different times and learn how YOUR particular combo handles minor pressure and temp variations.
If you're serious about handling this can occupy you for a time!
But it is a generally accepted rule of thumb that the hotter it gets (ambient temp) then you want more pressure, not less. Get an IR temp sensor gun and take readings at all different times and learn how YOUR particular combo handles minor pressure and temp variations.
If you're serious about handling this can occupy you for a time!
I keep it simple. I air up my tires to the "Max Load Cold PSI" listed on the sidewall in the winter......and drive the vehicle as normal......and change the air pressure 6 months in, to that of the door placard.
My theory is this.....tires lose pressure over time, I don't have to worry too much about "un even tire wear" due to over-inflation because as the tires lose pressure, they make complete contact with the road.
My theory is this.....tires lose pressure over time, I don't have to worry too much about "un even tire wear" due to over-inflation because as the tires lose pressure, they make complete contact with the road.
Go by the manufacturer's recommended tire pressure, regardless of season. If you don't your tires will wear out faster.
Check the tires early in the morning before the sun shines on them. The sun will shine on the tires and give you a false reading. You want the tires as cold as possible when you check them, hence the word "cold" tire pressure.
Always go by the sticker. My mom's Civic takes 32 PSI, my Century takes 30 PSI, and my brother's Explorer takes 26 PSI.
Check the tires early in the morning before the sun shines on them. The sun will shine on the tires and give you a false reading. You want the tires as cold as possible when you check them, hence the word "cold" tire pressure.
Always go by the sticker. My mom's Civic takes 32 PSI, my Century takes 30 PSI, and my brother's Explorer takes 26 PSI.
If you go by the max tire pressure, the contact patch on the road won't be as big. So you won't have as much traction. Always go by the recommended tire pressure.
Originally Posted By: ahoier
I keep it simple. I air up my tires to the "Max Load Cold PSI" listed on the sidewall in the winter......and drive the vehicle as normal......and change the air pressure 6 months in, to that of the door placard.
My theory is this.....tires lose pressure over time, I don't have to worry too much about "un even tire wear" due to over-inflation because as the tires lose pressure, they make complete contact with the road.
Originally Posted By: ahoier
I keep it simple. I air up my tires to the "Max Load Cold PSI" listed on the sidewall in the winter......and drive the vehicle as normal......and change the air pressure 6 months in, to that of the door placard.
My theory is this.....tires lose pressure over time, I don't have to worry too much about "un even tire wear" due to over-inflation because as the tires lose pressure, they make complete contact with the road.
Originally Posted By: SteveSRT8
While there are basic recommendations for all vehicles, every car and driver is a different animal. The door placard is just for a new stocker with factory rubber. The OPTIMUM pressure for your tire/wheel/auto/driver combo may vary a bit.
But it is a generally accepted rule of thumb that the hotter it gets (ambient temp) then you want more pressure, not less. Get an IR temp sensor gun and take readings at all different times and learn how YOUR particular combo handles minor pressure and temp variations.
If you're serious about handling this can occupy you for a time!
Agreed 100%. What's suitable for OEM tires might not be suitable for aftermarket replacements. My experience has been that higher pressures are needed in aftermarket replacement tires to maintain ride and handling compared to the OEM tires.
Deforming the tire creates heat. Combine that with sustained high-speed driving on very hot pavement, and a LOT of heat needs to be accounted for. Obviously the higher pressure, the less the tire deforms as it contacts the road, and so the less heat is generated internally to the tire.
While there are basic recommendations for all vehicles, every car and driver is a different animal. The door placard is just for a new stocker with factory rubber. The OPTIMUM pressure for your tire/wheel/auto/driver combo may vary a bit.
But it is a generally accepted rule of thumb that the hotter it gets (ambient temp) then you want more pressure, not less. Get an IR temp sensor gun and take readings at all different times and learn how YOUR particular combo handles minor pressure and temp variations.
If you're serious about handling this can occupy you for a time!
Agreed 100%. What's suitable for OEM tires might not be suitable for aftermarket replacements. My experience has been that higher pressures are needed in aftermarket replacement tires to maintain ride and handling compared to the OEM tires.
Deforming the tire creates heat. Combine that with sustained high-speed driving on very hot pavement, and a LOT of heat needs to be accounted for. Obviously the higher pressure, the less the tire deforms as it contacts the road, and so the less heat is generated internally to the tire.
Originally Posted By: CapriRacer
Originally Posted By: teddyboy
I always run 2-3 above the door panel recommendation during the spring and fall, slightly more than that during the winter. But during the summer I usually shoot for exactly what's on the door panel. My thinking is that there is less temperature variation at night during the summer so the tires aren't going through those heating and cooling cycles that cause you to lose pressure. And the tires heat up more when you're driving so you're that little bit over the recommended pressure once you start driving. Thoughts?
No, that's is 100% the wrong direction!
Heat is the tire killer! You want to minimize the amount of heat a tire experiences. You can't do anything about the ambient temperature, but you can do something about how much buildup there is - by adding more pressure to start with.
There is a sweet spot between heat and traction, too much heat the tire may burst, too little heat the traction may not be optimum. The best is to check the cold and hot pressure for the typical driving pattern, if the difference is too close (1-2 psi) the tire may not give optimum traction, even though the ride is good. For normal driving, normally I am looking 3-5 psi difference to achieve the sweet spot between ride comfort and traction.
Originally Posted By: teddyboy
I always run 2-3 above the door panel recommendation during the spring and fall, slightly more than that during the winter. But during the summer I usually shoot for exactly what's on the door panel. My thinking is that there is less temperature variation at night during the summer so the tires aren't going through those heating and cooling cycles that cause you to lose pressure. And the tires heat up more when you're driving so you're that little bit over the recommended pressure once you start driving. Thoughts?
No, that's is 100% the wrong direction!
Heat is the tire killer! You want to minimize the amount of heat a tire experiences. You can't do anything about the ambient temperature, but you can do something about how much buildup there is - by adding more pressure to start with.
There is a sweet spot between heat and traction, too much heat the tire may burst, too little heat the traction may not be optimum. The best is to check the cold and hot pressure for the typical driving pattern, if the difference is too close (1-2 psi) the tire may not give optimum traction, even though the ride is good. For normal driving, normally I am looking 3-5 psi difference to achieve the sweet spot between ride comfort and traction.
tire pressures have been debated in the cleanmpg and ecomodder forums a lot.
if you're running OE tires then the reccomended PSI on your door jam is for comfort.
it is completely safe to run MAX PSI COLD INFLATION on tire sidewall. As long as you have no traction issues or uneven tire wear. your tire will not explode either. Unless you hit a real nasty bump or pothole. takes over 300PSI to do that on a properly seated tire.
your main benefit is from less rolling resistance.
I run max psi or almost on all my vehicles with no problems or uneven tire wear.
if you're running OE tires then the reccomended PSI on your door jam is for comfort.
it is completely safe to run MAX PSI COLD INFLATION on tire sidewall. As long as you have no traction issues or uneven tire wear. your tire will not explode either. Unless you hit a real nasty bump or pothole. takes over 300PSI to do that on a properly seated tire.
your main benefit is from less rolling resistance.
I run max psi or almost on all my vehicles with no problems or uneven tire wear.
Last edited:
Originally Posted By: david_ES2
tire pressures have been debated in the cleanmpg and ecomodder forums a lot.........
Indeed, but I am going to take issue with some of the "facts" presented. Let's start with the most egregious one - burst pressure.
Unfortunately, many folks don't understand when they look at youtube videos what it is they are looking at. There's a couple of videos that show TRUCK tires exploding after the wheels are welded on. It should have been obvious that the point of the videos is that welding on wheels is a bad idea if there is an inflated tire on it. The pressure rise in the tire due to the heat of welding causes the tire pressure to spike - to the point where the tire can no longer contain the pressure - they burst! In all likelihood, these videos were produced to defend a lawsuit.
But these were TRUCK tires where the normal inflation pressure is around 100 psi - and they were designed for that pressure. Passenger car tires are designed to be used at a maximum of 35 psi - ergo, they burst at a much lower value.
Further, the fact that tires burst at a much higher value than their operating pressure points to a phenomenon called "fatigue" - that the breaking strength decreases if the load is cyclic, such as what happens when a tire rolls. In 50K miles, a tire is subject to something like 60 milion cycles - and if you look at what are called "S-N diagrams" - that plot breaking strength vs number of cycles - you'll find that the breaking strength of a tire needs to be 4 or 5 times what the single burst pressure is to assure the tire doesn't fail just due to fatigue.
We also know that the rubber in tires deteriorates over time - which means the burst pressure would also decrease over time.
Sidewall max pressure - what is it? How is it determined? Is it consistent from tire manufacturer to tire manufacturer? If it isn't derived from a test (or a theoretical calculation) AND the methodology of determining what is written there isn't consistent, how can anyone point to that pressure with any degree of confidence?
I will stop there - andf make a clear statement: If anyone points to the pressure on the sidewall, and suggests using that pressure (or some value derived from that pressure), you can be sure they do NOT understand tires and how they work!
tire pressures have been debated in the cleanmpg and ecomodder forums a lot.........
Indeed, but I am going to take issue with some of the "facts" presented. Let's start with the most egregious one - burst pressure.
Unfortunately, many folks don't understand when they look at youtube videos what it is they are looking at. There's a couple of videos that show TRUCK tires exploding after the wheels are welded on. It should have been obvious that the point of the videos is that welding on wheels is a bad idea if there is an inflated tire on it. The pressure rise in the tire due to the heat of welding causes the tire pressure to spike - to the point where the tire can no longer contain the pressure - they burst! In all likelihood, these videos were produced to defend a lawsuit.
But these were TRUCK tires where the normal inflation pressure is around 100 psi - and they were designed for that pressure. Passenger car tires are designed to be used at a maximum of 35 psi - ergo, they burst at a much lower value.
Further, the fact that tires burst at a much higher value than their operating pressure points to a phenomenon called "fatigue" - that the breaking strength decreases if the load is cyclic, such as what happens when a tire rolls. In 50K miles, a tire is subject to something like 60 milion cycles - and if you look at what are called "S-N diagrams" - that plot breaking strength vs number of cycles - you'll find that the breaking strength of a tire needs to be 4 or 5 times what the single burst pressure is to assure the tire doesn't fail just due to fatigue.
We also know that the rubber in tires deteriorates over time - which means the burst pressure would also decrease over time.
Sidewall max pressure - what is it? How is it determined? Is it consistent from tire manufacturer to tire manufacturer? If it isn't derived from a test (or a theoretical calculation) AND the methodology of determining what is written there isn't consistent, how can anyone point to that pressure with any degree of confidence?
I will stop there - andf make a clear statement: If anyone points to the pressure on the sidewall, and suggests using that pressure (or some value derived from that pressure), you can be sure they do NOT understand tires and how they work!
Last edited:
- Status
