Correct tire pressure

[Mach1]

I'm running BFG All Terrain KOs on my '04 F150 Super Crew 4x4. Tire size is 265/70R17. Max pressure stated on tire is 50 psi. Most of my driving is on paved roads (interstates/highways/country roads) with some done on gravel roads. I've generally had the pressure around 35 psi and with temperatures really starting to get cold around here I checked them today and they were at 25 psi. Needless to say I put some air in them. I'm just wondering if maintaining them around 35 psi is where I should be running them at. I know running them too low or high for extended time isn't good on the tire, handling, or gas mileage.

I checked the pressure on my wife's Accord and her's were at 22 psi with a max load of 40 psi. I put some in those too. I don't have BFG tires on the car, but can't remember what brand they are.

Edited December 10, 2010 by Mach1

[ALAN]

i got them same tires and size on my 01 f 150 i run 50 lbs in mine all the time,..i thought running to low u could ruin the tire..i think the sticker should say where to run them at

[92xj]

The higher the pressure in the tire the less friction on the road which can equal higher fuel milesage. If you have been running them all year at 35 and see even wear across the entire tire then I would keep them at 35. If thet center is more worn than the sides, I would drop the pressure a little and if the sides are more worn than the center I would increase them. Pesonally I run my tires on the high side, it makes me faster, but then I also air down when I get off road and am playing around in the dirts and rocks.

[LETMGROW]

I'm running BFG All Terrain KOs on my '04 F150 Super Crew 4x4. Tire size is 265/70R17. Max pressure stated on tire is 50 psi. Most of my driving is on paved roads (interstates/highways/country roads) with some done on gravel roads. I've generally had the pressure around 35 psi and with temperatures really starting to get cold around here I checked them today and they were at 25 psi. Needless to say I put some air in them. I'm just wondering if maintaining them around 35 psi is where I should be running them at. I know running them too low or high for extended time isn't good on the tire, handling, or gas mileage.

I checked the pressure on my wife's Accord and her's were at 22 psi with a max load of 40 psi. I put some in those too. I don't have BFG tires on the car, but can't remember what brand they are.

The BFG's are probably good around 35#. Checking the tread wear will tell you for sure. Someone else metioned this. The Accord should run 32-35# but checking the door jamb sticker will verify this.

Tires do tend to lose a little pressure in colder weather. Something bothers me though. If all were previously set at 35# and have read at 22 - 25# I would check your pressure guage with a known accurate one to be sure you are inflating the tires properly. I have seen a lot of variance in some of these guages. These can be damaged easily by dropping or from moisture in tires you check. The do wear out. I keep 2 guages in my tool box which have always read the same. Every now and then I check a tire with both guages to be sure they agree.

Just a thought.

Lynn

[Ravin R10 man]

I run the pressure the tire asks for, my silverado is at 50# or 55#.... cars are 35#,..if you are hauling something you need to inflate them more.. tire pressure is critical to good gas milage, outside temps have dropped alot up here..that alone will cause low tire pressure

[Mach1]

The BFG's are probably good around 35#. Checking the tread wear will tell you for sure. Someone else metioned this. The Accord should run 32-35# but checking the door jamb sticker will verify this.

Tires do tend to lose a little pressure in colder weather. Something bothers me though. If all were previously set at 35# and have read at 22 - 25# I would check your pressure guage with a known accurate one to be sure you are inflating the tires properly. I have seen a lot of variance in some of these guages. These can be damaged easily by dropping or from moisture in tires you check. The do wear out. I keep 2 guages in my tool box which have always read the same. Every now and then I check a tire with both guages to be sure they agree.

Just a thought.

Lynn

My brother-in-law and I were checking pressures in all the vehicles here last night (my F150, his Silverado, my wife's Accord, and my mother-in-law's Envoy). The Envoy and Silverado both have the monitoring system that gives the pressure on the dash. My mother-in-law said she was being alerted that the pressure was low. In his Silverado, the gauge showed 5 psi less than what the dash said. So we weren't exactly sure what to believe. The type of gauge we were using was one of the stick-type gauges. Do you think a dial-type would be better?

I don't think I'd checked the pressure in them since the temps dropped down like they have, so it's probably been a few weeks since I knew they were at 35. My wife had mentioned that her Accord had started to handle a little differently since it got cold and thought they needed some air. She came home from work this morning (she's a graveyard shift nurse) and said she thought the car's handling felt a little "loose." I asked her when she became a NASCAR driver.

[Shaun_300]

You should always put your tire pressure to the vehicle specs, not the tire specs. There's a sticker on the inside of the drivers door that will say what to run the tire pressures at. Most cars are between 30 and 35psi. The tire may say max pressure 44psi but that doesn't mean to run them at that pressure all the time. If you run them at that pressure all the time the center of the tread will wear out twice as quick as the rest of the tire and cut the life of your tires in half. Same with the trucks. Most trucks are 35psi. Tires may say max pressure 50psi, but again, run them at that pressure all the time and the centers will wear out faster than the rest of the tire. When you get to the 3/4 tons (GM anyway) the fronts should be set at 55psi and rears at 80psi. On the bigger trucks with the LT tires 80psi is usually the max for the tire. If you run LT tires (Like the BFG All Terrains) on your 1/2 ton truck don't run them at 80psi, run them at the vehicle specs. The pressure spec on the side of the tire is the maximum pressure the tire can be safely inflated and driven on. In the fall pump your tires up an extra 4-5psi as it will lose this once the cold air hits.

[stcif]

The way I have done it is I take chalk and draw a thick line across the tire tread. Drive it around the block. Check to see if the chalk is gone. Inflate until you get it so that the chalk wore off. If it is over inflated the chalk will stay along the edge.

I do not think you should go by what is on the vehicle as when the vehicle was made, how do they know what kind of tire you are going to put on?

This was how I used to run my old pick up with 35's on them. It allowed the tires to wear even and last the longest possible.

[LETMGROW]

While the chalk theory sounds good, it really isn't accurate. Even at slow speeds you will get " tire squirm " when turning This will wipe chalk off giving a fasle indication.

The door jamb stickers are reliable only for the specified tire size and load range specified on the sticker. Going from the standard load tires on a pick up to the LT load range D or E will void the stickers information if the sticker specified P tires.

Like Shaun said, the max. inflation numbers stamped on a tire are just that. Don't use these numbers as an inflation guide. Generally the tire will be a lot happier with somewhat lower pressure. The ride will certainly be better. Quite often the owners manual will have a chart for optional load range tire pressures.

Pressure for different size and load range tire other than what the vehicle came with is not cut and dried. The wheel width someone uses also comes into play. The wider the wheel, the more weight is distributed to the outside of the tire. Often you will have to add some pressure to keep the center of the tire from curling in.

As a rule of thumb we add about 5# if we upgrade from a P to load range C tire 10# from P to D, and 15 from P to E. We only use this as a guide on some of our fleet vehicles where we see the vehicle often for scheduled maintenance and can monitor the wear pattern. We also have to consider the loads carried. Some are run empty much of the time , others are overloaded all the time .It is certainly a guessing game. We keep records on the work invoices so we can reference the pressures and any changes we make.

We also have an account where the trucks were bought under a state bid format. These were 3/4 T. Ford 4 WD Super duty pickups. The door jamb sticker called for 60# pressure in the front tires and 80# in the rear. These trucks go off road only on occasion and seldom carry any load. We set the pressures at 45# all the way around and the tires have run over 40K and are still going and wearing evenly. They also get rotated every other oil change. You can actually ride in these trucks without seeing double from a harsh ride. If they still have this fleet we will downgrade to a lighter load range tire as they don't need the E's they came with. Trying to tailor the tire to the vehicle use is the key here. Also the drivers are told the pressures are lower than normal and they have been very good about increasing the pressure if they do have to load the truck heavily.

[Ravin R10 man]

I run the pressure the tire asks for, my silverado is at 50# or 55#.... cars are 35#,..if you are hauling something you need to inflate them more.. tire pressure is critical to good gas milage, outside temps have dropped alot up here..that alone will cause low tire pressure

I haul a fuel transfer tank on board for logging equipment..thus the higher tire pressure

Edited December 12, 2010 by Mathews XT Man

[LETMGROW]

I haul fuel on board for logging equipment..thus the higher tire pressure

Exactly the point I was trying to make. Different conditions call for different pressures.

Lynn

[Ravin R10 man]

Exactly the point I was trying to make. Different conditions call for different pressures.

Lynn

Yup...just wanted to make it clear i was not running light..thus my higher tire pressure

[jcot2773]

I have found that with a truck similar in size and weight (05 dodge ram) my tire says 44psi but i run typically about 39psi keeps the ride soft but also gets me a mile or two per gallon better.