Originally Posted by das_peikko
I was told today from a reliable source
Why not share who that "reliable source" was?
I was told today from a reliable source
Why not share who that "reliable source" was?
Tire Pressure
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Originally Posted by 1978elcamino
Thats a true statement the OP claims. I was also convinced the boogie man, easter bunny, tooth fairy, santa, the planters guy, mermaids all real as well. I go by my own tire psi, the fitting psi for each vehicle for the driving style of each one that wears the tire even throughout the life of the tire with routine rotations. This is usually a 3-5 psi above mfg's recomendations, when towing heavy the truck gets max psi in the rear, 42 while towing average loads. On Monday commuting, back to 38. The fusion usually does best around 36, still experimenting.
Hey...¾. Leave the Planters guy out of this! He's nuts you know.......
Thats a true statement the OP claims. I was also convinced the boogie man, easter bunny, tooth fairy, santa, the planters guy, mermaids all real as well. I go by my own tire psi, the fitting psi for each vehicle for the driving style of each one that wears the tire even throughout the life of the tire with routine rotations. This is usually a 3-5 psi above mfg's recomendations, when towing heavy the truck gets max psi in the rear, 42 while towing average loads. On Monday commuting, back to 38. The fusion usually does best around 36, still experimenting.
Hey...¾. Leave the Planters guy out of this! He's nuts you know.......
My take on all this...
Knowing that tire pressure increases with tire temperature doesn't mean we have to proactively compensate for it. The max tire pressure listed on the tire already takes that into account. If it says 47 or 51PSI max, that was written with the knowledge that it should be set at that pressure at room temperature, and it will get hotter/higher pressure in use.
Likewise for nominal pressure settings, if we want 32 or 35 PSI, doesn't mean we have to set to 4PSI lower than that to get there. There is already designed-in headroom for that temperature driven pressure difference.
I'm totally OK with seasonal or climate adjustments. If it's at a high of 100F to 115F for months at a time, there's no need to find a basement garage with 72F air conditioning to set the tire pressure. Set it in the 85F morning to the door placard or your personal preference, and let the design envelope handle it from there. If you find the tires too hard and do a lot of mid-day driving, knock a few pounds off. Likewise those living where it is below Zero for months at a time, set the tire pressure at some median temperature, which probably means adding a few pounds from the summertime pressure.
In the past 140K miles on the Corolla I've experimented with different tire pressures. I've found that different tires have a balance of optimal ride and handling characteristics at different pressures. I experiment until I find a balance that is optimal for me, my car, and my tires. I've never had to go below 30 or above 37. Every tire used in that range has worn evenly, a testament to both modern radial tire design, and good Toyota suspension design and execution.
I just got new tires on it, so I'm in the experimentation phase again. I happen to run slightly different pressures front and rear. The usual reasoning is that the front is heavier so put a little more pressure in the front tires, perhaps if someone here could explain why that reasoning is totally fallacious we can get into a discussion of what I'm doing here and why. However from the level of most of the discussion in this thread, I wonder if such a discussion here will be fruitful.
Knowing that tire pressure increases with tire temperature doesn't mean we have to proactively compensate for it. The max tire pressure listed on the tire already takes that into account. If it says 47 or 51PSI max, that was written with the knowledge that it should be set at that pressure at room temperature, and it will get hotter/higher pressure in use.
Likewise for nominal pressure settings, if we want 32 or 35 PSI, doesn't mean we have to set to 4PSI lower than that to get there. There is already designed-in headroom for that temperature driven pressure difference.
I'm totally OK with seasonal or climate adjustments. If it's at a high of 100F to 115F for months at a time, there's no need to find a basement garage with 72F air conditioning to set the tire pressure. Set it in the 85F morning to the door placard or your personal preference, and let the design envelope handle it from there. If you find the tires too hard and do a lot of mid-day driving, knock a few pounds off. Likewise those living where it is below Zero for months at a time, set the tire pressure at some median temperature, which probably means adding a few pounds from the summertime pressure.
In the past 140K miles on the Corolla I've experimented with different tire pressures. I've found that different tires have a balance of optimal ride and handling characteristics at different pressures. I experiment until I find a balance that is optimal for me, my car, and my tires. I've never had to go below 30 or above 37. Every tire used in that range has worn evenly, a testament to both modern radial tire design, and good Toyota suspension design and execution.
I just got new tires on it, so I'm in the experimentation phase again. I happen to run slightly different pressures front and rear. The usual reasoning is that the front is heavier so put a little more pressure in the front tires, perhaps if someone here could explain why that reasoning is totally fallacious we can get into a discussion of what I'm doing here and why. However from the level of most of the discussion in this thread, I wonder if such a discussion here will be fruitful.
In the old daze on bias ply tires we used to run double the recommended pressures at track events. Never had a problem.
You must be aware of the numerous variables applicable to your particular platform, tires, wheels, etc., before making any arbitrary judgements to raise/lower pressures.
You must be aware of the numerous variables applicable to your particular platform, tires, wheels, etc., before making any arbitrary judgements to raise/lower pressures.
The tires on my Tahoe say a max of 44 psi. The manual recommendation is 30 psi. I run them at 40 psi. No excessive "center" wear, turns easier, and rolls/coasts easier. It's a little more firm going over bumps, but that doesn't bother me.
Das-Peikko _ I was told today from a reliable source that you should set your cold tire pressure 4 psi below the max pressure printed on the tire. The owners manual recommendation or any sticker specifications on the car pertain to the original tires that came on the car from the factory and no longer apply. With new replacement tires, go by what the tire manufacturer says. That's what I was told today
That is incorrect on multiple fronts. The tire is part of the vehicle springing/busing system. If you run near max sidewall and its 5 -10 psig over door placard, you will hammer strut bearings out of your strut tops and hammer inner tirerod steering rack spherical joints. The vehicle engineers took in o account door placard inflation when designing the suspension.
I've NEVER had a tire wear properly when grossly overinflated. This will wear the center out.
If you corner hard and constantly wear the outside inch, go to better wheel aspect ratio and include a performance tire,
As a side note coming off Winter, Some drivers over inflate in the extreme cold. I would not run door placard COLD at 0 deg F.
Med duty trucks are a whole nuther ball of wax.
That is incorrect on multiple fronts. The tire is part of the vehicle springing/busing system. If you run near max sidewall and its 5 -10 psig over door placard, you will hammer strut bearings out of your strut tops and hammer inner tirerod steering rack spherical joints. The vehicle engineers took in o account door placard inflation when designing the suspension.
I've NEVER had a tire wear properly when grossly overinflated. This will wear the center out.
If you corner hard and constantly wear the outside inch, go to better wheel aspect ratio and include a performance tire,
As a side note coming off Winter, Some drivers over inflate in the extreme cold. I would not run door placard COLD at 0 deg F.
Med duty trucks are a whole nuther ball of wax.
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Originally Posted by Rmay635703
So if I have 51psi rated tires why not use them as designed? Better firmer cornering, better mpgs and perfectly flat tire wear.
That's a very broad generalization, IMO.
My 530i calls for 29 PSI front / 33 PSI rear. And if I run anything more than about 2-3 PSI above that, I end up with accelerated middle tread wear.
So if I have 51psi rated tires why not use them as designed? Better firmer cornering, better mpgs and perfectly flat tire wear.
That's a very broad generalization, IMO.
My 530i calls for 29 PSI front / 33 PSI rear. And if I run anything more than about 2-3 PSI above that, I end up with accelerated middle tread wear.
When in doubt do the chalk test.
Originally Posted by bubbatime
Originally Posted by ammolab
Originally Posted by Rmay635703
So if I have 51psi rated tires why not use them as designed? Better firmer cornering, better mpgs and perfectly flat tire wear.
At 51psi you will REDUCE the contact patch of the tire on the road...better cornering not gonna happen and tire will wear prematurely in the center.
Take two identical police patrol cars. Put one car at 30 PSI. Put the other car at 45 PSI. Put them on the police driving obstacle course, with the same driver. The one with 45 PSI in the tires will absolutely smoke, stomp, and out corner the car with 30 PSI in the tires, and have better lap times. Not even close. I know this for fact, as it was demonstrated to us in the police academy, the importance of tire pressure. The 45 PSI car handled very nicely. The 30 PSI car, wallowed all over the place.
Yeah of coarse it did , the 30psi was under filled by 20% I'm assuming .
Originally Posted by ammolab
Originally Posted by Rmay635703
So if I have 51psi rated tires why not use them as designed? Better firmer cornering, better mpgs and perfectly flat tire wear.
At 51psi you will REDUCE the contact patch of the tire on the road...better cornering not gonna happen and tire will wear prematurely in the center.
Take two identical police patrol cars. Put one car at 30 PSI. Put the other car at 45 PSI. Put them on the police driving obstacle course, with the same driver. The one with 45 PSI in the tires will absolutely smoke, stomp, and out corner the car with 30 PSI in the tires, and have better lap times. Not even close. I know this for fact, as it was demonstrated to us in the police academy, the importance of tire pressure. The 45 PSI car handled very nicely. The 30 PSI car, wallowed all over the place.
Yeah of coarse it did , the 30psi was under filled by 20% I'm assuming .
Originally Posted by Quattro Pete
Originally Posted by Rmay635703
So if I have 51psi rated tires why not use them as designed? Better firmer cornering, better mpgs and perfectly flat tire wear.
That's a very broad generalization, IMO.
My 530i calls for 29 PSI front / 33 PSI rear. And if I run anything more than about 2-3 PSI above that, I end up with accelerated middle tread wear.
Middle tread wear is only a RWD problem
My guess is you drive in a spirited fashion and get less than 50000 miles a set.
My last set had 80,000 miles on the clock,
You do what you want, I'll stick with what I'm doing
Originally Posted by Rmay635703
So if I have 51psi rated tires why not use them as designed? Better firmer cornering, better mpgs and perfectly flat tire wear.
That's a very broad generalization, IMO.
My 530i calls for 29 PSI front / 33 PSI rear. And if I run anything more than about 2-3 PSI above that, I end up with accelerated middle tread wear.
Middle tread wear is only a RWD problem
My guess is you drive in a spirited fashion and get less than 50000 miles a set.
My last set had 80,000 miles on the clock,
You do what you want, I'll stick with what I'm doing
Originally Posted by Rmay635703
Originally Posted by Quattro Pete
Originally Posted by Rmay635703
So if I have 51psi rated tires why not use them as designed? Better firmer cornering, better mpgs and perfectly flat tire wear.
That's a very broad generalization, IMO.
My 530i calls for 29 PSI front / 33 PSI rear. And if I run anything more than about 2-3 PSI above that, I end up with accelerated middle tread wear.
Middle tread wear is only a RWD problem
Yeah, so again, a broad generalization that doesn't always apply as there are plenty of RWD vehicles out there.
Just because a tire was designed to support a maximum of 51 PSI without blowing up does not mean that this is this tire's optimal running pressure in one's particular application.
Originally Posted by Quattro Pete
Originally Posted by Rmay635703
So if I have 51psi rated tires why not use them as designed? Better firmer cornering, better mpgs and perfectly flat tire wear.
That's a very broad generalization, IMO.
My 530i calls for 29 PSI front / 33 PSI rear. And if I run anything more than about 2-3 PSI above that, I end up with accelerated middle tread wear.
Middle tread wear is only a RWD problem
Yeah, so again, a broad generalization that doesn't always apply as there are plenty of RWD vehicles out there.
Just because a tire was designed to support a maximum of 51 PSI without blowing up does not mean that this is this tire's optimal running pressure in one's particular application.
I run the tires on our cars ar the max pressure listed on the sidewall . Greater tire life and greater MPG .
Originally Posted by WyrTwister
I run the tires on our cars ar the max pressure listed on the sidewall . Greater tire life and greater MPG .
That is a maximum cold pressure, so depending on the weather or driving conditions it can cause an unsafe condition. It can also decrease the life expectancy.
I think the maximum pressure listed on the tires on my BMW is 50 PSI, so you suggest running them at that?
I run the tires on our cars ar the max pressure listed on the sidewall . Greater tire life and greater MPG .
That is a maximum cold pressure, so depending on the weather or driving conditions it can cause an unsafe condition. It can also decrease the life expectancy.
I think the maximum pressure listed on the tires on my BMW is 50 PSI, so you suggest running them at that?
This comes up on this board frequently… There are those that say use the manufacturer's recommended pressure, some that say adjust your pressure depending on the load, those that say adjust your pressure based on footprint of the tire, and any other number of methods. In the end, it's your vehicle.
Originally Posted by WyrTwister
I run the tires on our cars ar the max pressure listed on the sidewall . Greater tire life and greater MPG .
Wow.
Please don't suggest others do the same.
I run the tires on our cars ar the max pressure listed on the sidewall . Greater tire life and greater MPG .
Wow.
Please don't suggest others do the same.
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Im sure you guys remember the Ford Firestone lawsuit. It was documented that it was not only the tire coming apart but the recommended PSI was too low from the decal on the door. Research claims low psi was a large contributor to the sudden tire failure. If I remember correctly it was 26psi for some explorers. After replacement tires were installed a new door decal was placed over the original decal with a higher recommended pressure of something like 32 or 35 psi. IMHO I would much rather have higher than lower tire pressure.
I run 36 on the Escape and Silverado and 44 on the Crown Vic. The tires on the Escape are at 30K miles and while I have never rotated them they are wearing perfectly even.
Originally Posted by das_peikko
I was told today from a reliable source that you should set your cold tire pressure 4 psi below the max pressure printed on the tire. The owners manual recommendation or any sticker specifications on the car pertain to the original tires that came on the car from the factory and no longer apply. With new replacement tires, go by what the tire manufacturer says. That's what I was told today.
Hyper-milers, people who do high MPG tricks, do this. Its basically safe to stay at least 4 psi under the max on the tire sidewall. Ride is harsher, and glass or debris on the road is more likely to cause a puncture.
I normally won't go above +3psi from what is printed on the car itself, usually found on the door pillars sticker placard and/or in the owner's manual. The tire printed sidewall pressure is an upper limit, never exceed. ....
If its cold outside or snowing, and you don't go over 75 mph, with light loads, then you can put in -3psi less than the placard pressure. Never less than that, 3 psi under. .... BMW owner's manuals actually varied the tire pressure based on speed (more psi for more speed) and passenger numbers would push tire psi recomendations up as well, in a chart in the owners manual.
Originally Posted by rooflessVW
Originally Posted by WyrTwister
I run the tires on our cars ar the max pressure listed on the sidewall . Greater tire life and greater MPG .
Wow. Please don't suggest others do the same.
Not a good idea, especially if ice or snow around. At least 4 psi under sidewall max is OK, not all the way to sidewall pressure. Need some margin I think.
I was told today from a reliable source that you should set your cold tire pressure 4 psi below the max pressure printed on the tire. The owners manual recommendation or any sticker specifications on the car pertain to the original tires that came on the car from the factory and no longer apply. With new replacement tires, go by what the tire manufacturer says. That's what I was told today.
Hyper-milers, people who do high MPG tricks, do this. Its basically safe to stay at least 4 psi under the max on the tire sidewall. Ride is harsher, and glass or debris on the road is more likely to cause a puncture.
I normally won't go above +3psi from what is printed on the car itself, usually found on the door pillars sticker placard and/or in the owner's manual. The tire printed sidewall pressure is an upper limit, never exceed. ....
If its cold outside or snowing, and you don't go over 75 mph, with light loads, then you can put in -3psi less than the placard pressure. Never less than that, 3 psi under. .... BMW owner's manuals actually varied the tire pressure based on speed (more psi for more speed) and passenger numbers would push tire psi recomendations up as well, in a chart in the owners manual.
Originally Posted by rooflessVW
Originally Posted by WyrTwister
I run the tires on our cars ar the max pressure listed on the sidewall . Greater tire life and greater MPG .
Wow. Please don't suggest others do the same.
Not a good idea, especially if ice or snow around. At least 4 psi under sidewall max is OK, not all the way to sidewall pressure. Need some margin I think.
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Not to complicate this even further, but remember Deflate-Gate? Patriots. .... Typically you can put air in your tires to have the right placard pressure accounting for the lowest temperature you expect in the next month. As in, we know we get about a 1 psi drop in pressure per 10 degrees F. This isn't hard to calculate.
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