Tire pressures ....

[KFC911]

I have three vehicles that I need to monitor, that I never drive ... so I can't fine tune them to my preference.

Got my mom a Toyota Highlander (to replace her Lexus someone totaled ), and the tires were inflated to 40 PSI (too much), with the max PSI rating on the tire being 44. I dropped them back to 35 (that's what I keep my F150 at), but upon looking, the sticker on the door says 30 PSI for that tire size.

Another vehicle is also 5 PSI too much imo... inflated by a garage who installed them.

Anyways ... seems as if the recommended PSI on the vehicles' stickers is what I want to go with.... what say ye?

Thanks!

[masraum]

Originally Posted by KC911

I have three vehicles that I need to monitor, that I never drive ... so I can't fine tune them to my preference.

Got my mom a Toyota Highlander (to replace her Lexus someone totaled ), and the tires were inflated to 40 PSI (too much), with the max PSI rating on the tire being 44. I dropped them back to 35 (that's what I keep my F150 at), but upon looking, the sticker on the door says 30 PSI for that tire size.

Another vehicle is also 5 PSI too much imo... inflated by a garage who installed them.

Anyways ... seems as if the recommended PSI on the vehicles' stickers is what I want to go with.... what say ye?

Thanks!

I usually go with the recommendations on the sticker. Actually, I usually add 2-4psi to the numbers on the sticker, that gives me a little extra time as they slowly lose air.

For your mom's highlander, it's probably not a big deal assuming she's not a speed demon. It's probably fine to start at 33-35 and then top them up when they get down to 27-28 (since the reco is 30). I find that for most cars in most situations, there's a range of 5-10 psi where performance is similar, so I start at the top of the range and top up when I get near the bottom of the range.

I usually use the door sticker as my starting point and adjust based on how things feel when I drive the car. Most cars aren't that picky. Cars like miata, boxster, 911 are usually the pickiest of the bunch (or maybe I notice more because of the way that I drive them)

[VINMAN]

I normally go by the door sticker but, a few of my vehicles have oversized aftermarket wheels and tires. With those I go by the tire manufacturers recommendation based on the vehicle.

.

[KFC911]

Thanks guys! Stickers will be my reference point and I'll go from there...

[Scott Douglas]

I don't go by the door sticker. Used to, but not any more. That is the reco from the factory which will give you the 'nicest' ride but won't be the best thing for tire life. I run 35-37 psi in my wife's CR-V. It may be a little harsher than the sticker reco of 30 but it sure helps with the gas mileage and how the car handles. I run closer to 40 in my Accord with the 35 series 19" tires. It's not a 'soft' ride for sure but it does wonders for the handling and gas mileage both.
If you don't believe me on the gas mileage, just try pushing your car with the sticker reco psi in the tires, then pump them up to 35-40. It makes a world of difference that the engine feels too.
I was told that the reco of the highest pressure on the tire is what the mfg'r of the tire says is the pressure at which the tire is its strongest.
YMMV of course.

[wdfifteen]

I add 2 or 3 PSI to the recommended pressure.
With nothing more to go on but articles in automotive magazines, I believe the manufacturer's recommended tire pressure is a compromise between ride quality, tire wear, and mileage. Ride quality would call for a lower pressure. Since I'm not that interested in a softer ride, I add 2 or 3 PSI to the recommended pressure to offset that criterion.

[GH85Carrera]

With the El Camino, after over 31 years I know to run 36 PSI front and 26 rear. If I run any more in the rear it will wear out the cent of the tire way faster than the outer edges. At 26, it is flat even wear and the tires last longer.

For the 911, it depends on usage. For a cross country trip fully loaded with a passenger and and enough luggage for a two week vacation, I raise them up. For a track day they are adjusted as needed.

[stomachmonkey]

I go by the door card.

+ or - a couple of pounds is no big deal

we all love the feel of an overinflated tire, car seems to turn easier, more responsively but that comes at the cost of traction which given the trade off I'll stick within the car manufacturers recommended range.

lowering rolling resistance lowers traction.

[David Inc.]

Originally Posted by wdfifteen

I add 2 or 3 PSI to the recommended pressure.
With nothing more to go on but articles in automotive magazines, I believe the manufacturer's recommended tire pressure is a compromise between ride quality, tire wear, and mileage. Ride quality would call for a lower pressure. Since I'm not that interested in a softer ride, I add 2 or 3 PSI to the recommended pressure to offset that criterion.

The rated pressures are also for the max vehicle load. For example my wife's small SUV is 36/42 psi front/rear, which is way too high in the rear when it's just her and I in the car.

[KFC911]

Thanks again all!

[911 Rod]

The alignment guy I used for years was adamant that you use the max pressure as on the tire wall.
He would lecture this too me every time I went in as he didn't remember me and told me the same story about a wandering BMW 8 series that a gazillion lbs. fixed.
My point is be careful who you get advice from.
I go by the door sticker.

[hughc]

I'm glad this thread was started as I am about to replace the rear tires on my SC. They are 245's and badly worn in the centers, as if over inflated, yet I've kept them at 34 lbs as per sticker recommendation. So now I'm thinking I should inflate the new tires at 32 lbs but I'm not convinced that would make an appreciable difference.
Do you guys have any suggestions??
Thx
hughc

[masraum]

Originally Posted by hughc

I'm glad this thread was started as I am about to replace the rear tires on my SC. They are 245's and badly worn in the centers, as if over inflated, yet I've kept them at 34 lbs as per sticker recommendation. So now I'm thinking I should inflate the new tires at 32 lbs but I'm not convinced that would make an appreciable difference.
Do you guys have any suggestions??
Thx
hughc

What size wheels are they on?

If you've got an SC with the standard 16x6 and 16x7 wheels, yes, 245 45 16s "fit" on the back, but they don't fit right and you're not likely to ever get good wear. If you've got 16x7" wheels on the back, go back to the stock 225 50 16 tires and you'll get better performance and wear. The problem is that the 245 45 16 are too wide for the wheel (you'd want a 16x8 or 16x9 for those) so the lips of the tire are pinched inward which causes the carcase to bow across the tread. It also means that the tires won't corner as well because there will be more movement/roll of the oversized tire.

If your rear wheels are 16x9 or maybe 16x8, then disregard ^that^.

My old '88 targa came with 245 45 16 on the stock sized wheels when I bought it. I had the same issues. I switched back to the stock tire size.

[hughc]

The wheels are 17" and I believe 8" wide or maybe even 9". They are at the shop now so I won't be able to verify for a few days.
Hugh

[Bill Douglas]

I tend to go with what it says in the manual, then raise it by 2 or 3 psi.

My tires tend to wear on the sides more, so a bit of over inflation won't hurt.

If the car is getting rattly or a bit too bumpy I drop it one psi until the rattles stop.

[Otter74]

I'm usually between sticker and +5. Thirty years ago, I got a new Sentra SE-R. When it was a few months old, my mom commandeered it to take my sister on a college-visiting trip. Got it back and it rode like the tires were filled with concrete. Checked the pressures and they were all at like 65psi. I think my mom or my sister read the max pressure on the sidewall and thought that's what you were supposed to set them at. Yeesh!!

[hughc]

Originally Posted by Bill Douglas

I tend to go with what it says in the manual, then raise it by 2 or 3 psi.

My tires tend to wear on the sides more, so a bit of over inflation won't hurt.

If the car is getting rattly or a bit too bumpy I drop it one psi until the rattles stop.

My tires are wearing in the center so I think increasing the pressure would aggravate the problem , but I could be wrong. It just doesn't feel right to be running pressures lower than the recommended 34 lbs.

[wdfifteen]

Wednesday when it was 60 degrees out my tire pressure was just fine. Now that the temp has dropped 35 degrees I've had to add air to bring it up to "stop bothering me with that annoying warning light" pressure. So next week when it's 60 degrees again the pressure should theoretically be too high. But I won't get a warning light. Does that mean the manufacturers don't car about excessive pressure?

[A930Rocket]

I run my truck tires at 40 psi front and back. My last set of tires lasted 55,000 miles with even wear.

[KFC911]

Originally Posted by A930Rocket

I run my truck tires at 40 psi front and back. My last set of tires lasted 55,000 miles with even wear.

Is that on an F150 or similar? Like a lot of things, there are trade offs, but ya can't beat that for longevity .... which brand?

My uncle had a Mustang with tires over 90K ... he wanted to hit 100K ... maypops