5 lbs of air makes a difference

I had low air at my oil change @31 per tire so put 36 in and that still didn't improve the ride. I looked closer at my tires and they indicate 55 max cold. 265/55/17...

I only have them at 41 now but might go to 44.. steering bounce over random bumps is a ton better. I was actually starting to become disappointed in my 6-month-old KYB struts, but it was just winter cold draining my air.

Cool... run what feels and works best for you within the tires limits.

It helps to know what tire and load range you are actually working with it... perhaps others can chime in with their experiences.

I'm running 36lbs in my stock 2014 tires. The funny thing is my tire pressure light came on the other day. I drove home and parked in the garage. Next morning went out and checked pressure. 36lbs in all four. But, the idiot light is still on!

Frederick1 said:

I'm running 36lbs in my stock 2014 tires. The funny thing is my tire pressure light came on the other day. I drove home and parked in the garage. Next morning went out and checked pressure. 36lbs in all four. But, the idiot light is still on!

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Check the spare, there’s a TPMS on there too.

Frederick1 said:

I'm running 36lbs in my stock 2014 tires. The funny thing is my tire pressure light came on the other day. I drove home and parked in the garage. Next morning went out and checked pressure. 36lbs in all four. But, the idiot light is still on!

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Spare tire.

Thanks guys! I never thought of that.

If your doing most driving on pavement your tires will wear in the center much faster! You don't go by the tires inflation rating, you go by what the vehicle manufacturer recommends, that is if you want even tire wear.

Just an fyi, if a tire is overpressurized then the light will go on too. Alot of manufacturers are doing this now. Not on ours but newer vehicles.

Jim_A said:

If your doing most driving on pavement your tires will wear in the center much faster! You don't go by the tires inflation rating, you go by what the vehicle manufacturer recommends, that is if you want even tire wear.

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In my experience, what you mention here is only applicable when using tires of the same size and load rating the vehicle came with. Once you deviate from that, as most here do, you have to go by the recommendation of the tire manufacturer, or experiment to find the best balance of ride quality and wear. Obviously “how” the vehicle is being used makes a difference too. For example, you may want to increase pressure if doing mostly highway driving and towing, where for off road, you generally have to air them down, depending on terrain. For my situation with 265/70/17 Wildpeak AT3W tires, I’ve found 38psi to be the sweet spot for everyday driving.

Terminator03 said:

In my experience, what you mention here is only applicable when using tires of the same size and load rating the vehicle came with. Once you deviate from that, as most here do, you have to go by the recommendation of the tire manufacturer, or experiment to find the best balance of ride quality and wear. Obviously “how” the vehicle is being used makes a difference too. For example, you may want to increase pressure if doing mostly highway driving and towing, where for off road, you generally have to air them down, depending on terrain. For my situation with 265/70/17 Wildpeak AT3W tires, I’ve found 38psi to be the sweet spot for everyday driving.

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There are many variables, I'm talking generally speaking.

MT Runner said:

Check the spare, there’s a TPMS on there too.

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I learned that and putting air in with the valve on top was a blast.

I don't care what a vehicle mfr says to do with tires. They didn't manufacture or test that tire. The tire company did. Remember all those Ford Explorers flipping over? Ford was telling people to way under inflate the tires for a more comfortable ride. The tire is the only part of your vehicle that touches the road, so I do what they say.

Only if your running the OE sized tire

Jim_A said:

If your doing most driving on pavement your tires will wear in the center much faster! You don't go by the tires inflation rating, you go by what the vehicle manufacturer recommends, that is if you want even tire wear.

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otherwise you go by the tires inflation rating b/c it is based on that specific tire size ...

BlackCloud said:

I don't care what a vehicle mfr says to do with tires. They didn't manufacture or test that tire. The tire company did. Remember all those Ford Explorers flipping over? Ford was telling people to way under inflate the tires for a more comfortable ride. The tire is the only part of your vehicle that touches the road, so I do what they say.

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Correct me if I'm wrong, but I'm not aware of tire manufacturers providing a recommended inflation, there's too much variance between vehicles for a one-size-fits-all recommendation. They DO provide a max inflation rating, which is just that, the maximum. You don't want to be running that or you're in for a harsh ride and uneven wear.

When I switched to 265/70/17 Falkens, I started at 35, but after noticing the center wearing more than the sides, dropped down to 33 and that fixed it, plus it feels a little more stable at highway speeds.

Sent from my SM-G950U using Tapatalk

Tire manufacturers only specify maximum inflation pressure. This has no correlation to the "correct" inflation pressure. Their are two good ways to check for "proper" tire pressure. The chalk method (which you can google) and the temperature test (below). Both of these tests are meant to make sure that tire pressures used are creating the ideal contact patch between the tire and pavement. In my experience, even tires of wildly different characteristics and sizes, when mounted on the same vehicle, are usually happiest at or near the pressures indicated on the vehicle manufacturers door placard.

This isn't a one size fits all thing though... If your rock crawling the "best' pressure might be significantly lower, and if your towing the "best" pressure might be significantly higher. YMMV (literally). You may personally prefer higher or lower pressures for efficiency or comfort, but any pressure that compromises the contact patch may upset the handling dynamics of the vehicle or cause excessive tire wear. If you and your wallet are okay with wearing out tires a little faster for the sake of comfort... then gal' dern it, I won't judge ya'.

For those interested the temperature tire pressure method is:
1) Drive the vehicle normally for ten to fifteen minutes.
2) Stop the vehicle in a safe location and, using a non-contact thermometer, measure the temperature of the tire tread in three places. Once at the outside edge of the tread, once in the center of the tread, and once at the inside edge of the tread.
3) Compare these temperatures. A properly inflated tire will show that all three temperatures are approximately equal.

Significant temperature differences (>5 degrees F) indicate improperly inflated tires or suspension/alignment issues and can be interpreted as follows:

If temperatures are read from outside to inside and indicate
High, low, high = tires under-inflated
Low, high, low = tires over-inflated
Low, high, high = Excessive toe out or negative camber
High, high, low = Excessive toe in or positive camber

The temperature test does not require letting the tires cool between testing. If pressures are off add/release air and repeat.

Sorry if this is all a bit dry, but... science!:rockon:

I can’t imagine ever running at 40+ PSI. Is that wise?

Can't be horrible at 41.. Maybe once the snow melts, I can try a temp test..

Jim_A said:

If your doing most driving on pavement your tires will wear in the center much faster! You don't go by the tires inflation rating, you go by what the vehicle manufacturer recommends, that is if you want even tire wear.

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right. You don't run the tire's max... Look on your door jamb sticker. If you have non stock size tires and/or LT tires, etc. then I think you can research with the manufacturer for the recommended psi based on the GVWR. Running max psi will wear them out faster...

ElZilcho said:

Tire manufacturers only specify maximum inflation pressure.

[...]

Sorry if this is all a bit dry, but... science!:rockon:

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GREAT post! Spot on. I have been using an IR thermometer for years to monitor both vehicle and trailer tires. My fiberglass trailer is only 1000lb loaded so I go through tires too fast for wearing the center even at 30-35 psi as per the trailer's manufacturer recommendation. I fear overheating if I go lower, especially here in the Southwest's summers.

The fun is when the temp is HIGH LOW LOW on your vehicle's tires (not the 4R in my case)....

LarsBars said:

Correct me if I'm wrong, but I'm not aware of tire manufacturers providing a recommended inflation, there's too much variance between vehicles for a one-size-fits-all recommendation. [...]

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You are right, of course they don't. But you can email them and get yours.

BlackCloud said:

I don't care what a vehicle mfr says to do with tires. They didn't manufacture or test that tire. The tire company did. Remember all those Ford Explorers flipping over? Ford was telling people to way under inflate the tires for a more comfortable ride. The tire is the only part of your vehicle that touches the road, so I do what they say.

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I really hope you get what they say by talking to them or emailing them because that's about the only way...and it does work.

Bluesky 07 said:

I can’t imagine ever running at 40+ PSI. Is that wise?

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You cannot but you must if you are running LT tires and want to maintain the load rating. When moving from P to LT, email the tire company and they will let you know the appropriate pressure. I bet you won't like the ride if the midsize SUV is empty, but anything less cuts from the tires' load rating.

D and E tires put on midsize SUVs seem alright at much lower than recommended pressures because their starting load rating is way above the required one for the 4Runner or Wrangler, but a tire company will only recommend the direct equivalent PSI.

Even in the case of the LT-C Nitto Ridge Grapplers, Nitto told me 44 psi over email. This is not why I went with the Wildpeaks, but it was a factor. One less thing to think about.

Basically, if you are running LT on a loaded vehicle that is towing, you may want to definitely know what the recommended pressure by the tire company is, which is...not found on the sidewall....

I used to work for a driving school that was owned by Ford. We got some of the first Focuses to hit North America back in the early 2000s. Whoever did the post delivery inspection on them cranked the tire pressures up to the tire max of 44 psi, completely ignoring the B pillar sticker pressure of 32. The cars were unsafe. They bounced and steered like they were on beach balls. No traction running just on the centers of the tires. Deflated them to 32 psi and they handled excellently. Didn't go beyond about 12,000 miles without breaking something, but at least they rode well. I always recommend starting with the vehicle manufacturer's pressures and going from there.

Google "tire pressure chalk test". It's one way you can check for even wear.