Does anybody run 40psi instead of the 35psi?

[rangerfan]

Does anyone run 40 psi in their tires instead of the recommended 35 psi? I'm just curious to see if there will be any consequences by running 5 psi over the recommended.

[stu37d]

When I was spending 3.5 hours a day going to and from work, trying to squeeze a few extra miles out of a tank of gas, I would run a pound or 2 over the recommended. I also changed my oil about once a month and rotated the tires at every oil change. I didn't notice any extra wear on the tires- BTW, it was mostly highway miles to work, not too many curves and pretty good roads. I don't know if I would go 5 over, except maybe when you have a heavy load in the bed (only for a short time, though). Those limits were set for a reason.

[g_k50]

Obama runs 40 in his truck, he suggest you do too.

[rangerfan]

Don't know what Obama has to do with this?

Will running 40 psi give me better MPG's?

[g_k50]

Obama suggested that in order to reduce our energy consumption we shoul make sure our tires are properly inflated.

Then I laughed.

It's funny because it's true.

[Traxxis]

Originally Posted by g_k50

Obama runs 40 in his truck, he suggest you do too.

lol, nice.

[sfcwoodret]

Don't run over the recommended pressure because tires must have the ability to expand and contract based on weather temperature. Don't mess with Mother Nature!

[Bear River]

The tires do have a margin of safety, and would be ok being slightly overfilled, but it may wear out he center of the tread more quickly. You are better off using a tire with lower rolling resistance than messing with tire pressures.

[racsan]

i run 44 in my uniroyal liberators (rated for 50 psi max) yes, it will wear the center faster, but its not extremely bad. thnk about riding a bike, if the tires are low or rock-hard, whats easier to pedal? i did lower them to 30 this week when my wife needed to have a cake trasported to the local fair, needed the smoothest ride i could get for the trip. havent aired back up yet, but i will. i'll sacrifice a little tire life and ride quality for fuel savings. my tires last quite awhile anyhow due to having 2 sets, one for summer and another set for winter. ive only ran at the max 50 psi once when i had the trailer on and heavily loaded with oak firewood. id ay the worst thing about running over 30-35 psi is braking ability, less contact with the road can equal less grip when coming to a stop. but i usually only have stopping issues when heavily loaded or on wet pavement. these tires just dont grip wet roads well, i was pulled over late one night after going around a corner and losing traction. i just let the tires spin until i shifted to the next gear. luckily i got off with a warning.

[smlford]

I usually run a few pounds higher in all my vehicles. It does help with improved mileage (~1 to 2 MPG)
The important thing is not to exceed the max pressure that is listed on the tire.
As stated above it could wear the center of your tires out faster if you have too much pressure. It will also increase the ride stiffness in the ranger. I didn't notive any ride difference in my F-350

On my Porsche, which already has a firm ride, it reduces understeer and tire roll in corners and actually improves the handling of the car. This is with a 2 PSI increase.

[G2IC_Wraith]

Originally Posted by racsan

i run 44 in my Uniroyal liberators (rated for 50 psi max) yes, it will wear the center faster, but its not extremely bad. think about riding a bike, if the tires are low or rock-hard, whats easier to pedal? i did lower them to 30 this week when my wife needed to have a cake transported to the local fair, needed the smoothest ride i could get for the trip. haven't aired back up yet, but i will. I'll sacrifice a little tire life and ride quality for fuel savings. my tires last quite awhile anyhow due to having 2 sets, one for summer and another set for winter. I've only ran at the max 50 psi once when i had the trailer on and heavily loaded with oak firewood. id say the worst thing about running over 30-35 psi is braking ability, less contact with the road can equal less grip when coming to a stop. but i usually only have stopping issues when heavily loaded or on wet pavement. these tires just don't grip wet roads well, i was pulled over late one night after going around a corner and losing traction. i just let the tires spin until i shifted to the next gear. luckily i got off with a warning.

Not to sound like a wet blanket, but the first problem here is relying on the tire's sidewall marking instead of the using the pressure listed inside the door and in the owner's manual that was recommended by the engineering team at the factory. This is a common mistake, since many do not realize that the pressures listed on the side are a reference for "Max PSI @ Max load". IE - The tire is safe to use with an individual load of X lbs and inflated to Y PSI to handle that load. So if a tire said it could handle 1800 lbs then using the bed as an example: (1800 x 2) = 3600 - ~1500 (estimated weight over the rear axle) = 2100 lbs You would have to be hauling 1Ton+ in the bed to justify inflating tires to the Max PSI. Also 1800 lbs is just a rounded figure, most tires that fit our trucks will handle more 1600 to 2100 lbs depending on the tire you choose.

EDIT - Here is an example of this: http://www.tirerack.com/tires/tirete....jsp?techid=21

This may sound like a lot of technical garbage, but it is important to understand. The point of all this to the OP, and anyone else is there is a specific volume of air that is required to carry the load of the truck alone, and most daily light loads. That volume was calculated by the factory given a range of sizes and types of tires that come on the different model trucks. While it is true that this number has a lot of assumptions built into it, there are safety concerns, ride comfort, wear life, fuel economy, etc.. Sure tires differ in design, and deviating +/- 1-3 lbs from the factory recommended setting can be done to "tune" your truck for best wear, MPG, and braking. It may not sound like much, but 1 lbs of air can make a lot of difference in how a tire will perform. Not to pick on Racsan, but every problem he listed is a direct result of having that much air in a tire carrying a relatively light load.

Happy 4th everyone, be safe. That includes on the road, and in the back yard.

[pawpaw]

Yup many things to consider when airing up above the specified figure on the door sticker.

As mentioned, ride, handeling, braking, traction & tire wear are affected, some more thigs to add to that list, internal & external tire impact damage, wheel bearings, brake, suspenaion, steering, running gear including wheel rims & body parts also take an additional beating from over aired up tires!!!!

[Bear River]

I agree, I have seen lots of premature wheel bearing failures that were the result of overly firm tires. And it does make the ride a lot rougher, especially if the roads aren't in good condition.