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My 08 rx350 recently returned from the local dealership with all tires at 36 psi. cold. I checked the door panel and and they are supposed to be at 30 psi when cold. Bad dealership or am I missing something?

Thanks

Door placard typically shows pressure for maximum comfort/smooth ride. If you want better fuel economy and can handle a more firm and bumpy ride you can inflate to the max pressure shown on the tire sidewall.

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My 08 rx350 recently returned from the local dealership with all tires at 36 psi. cold. I checked the door panel and and they are supposed to be at 30 psi when cold. Bad dealership or am I missing something?

Thanks

Door placard typically shows pressure for maximum comfort/smooth ride. If you want better fuel economy and can handle a more firm and bumpy ride you can inflate to the max pressure shown on the tire sidewall.

don't read your door sticker, read what is on the tire only. again read the tire only. there are lots of tires that can be on these cars just read my mich 18 in tire MAX 44 psi

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I would say ONLY read your door sticker, that is if you are using the OEM size tire. Your car was tested and validated with tires that were aired to the pressure stated on the door. The handling, ABS computer and many other things I wouldn't even begin to understand were all validated with the specs that are listed for that size and tire rating at the air pressure stated. The same tire can be used on many different size cars and applications for instance my Accord V6 gets 32psi front and 29psi rear good to vehicle rated weight capacity. So when the tires are rotated the air has to be adjusted. This is due to the engine and front wheel drive weight. This same tire on a heavier car would most likely require higher pressure. You won't be wrong if you use the pressure that the car Mfg gives you. You will not hurt the tire with a higher pressure up to rated Max but you may hurt the handling of your car and that may hurt you. Remember the tire Mfg gives you the max pressure with the max weight rating for that tire, they don't know what kind of car that tire is going on.

Jeff

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FWIW, I've been running the tires on our RX350 at 33 psi all around. The door placard is the mfg recommended pressure. The sidewall of the tire is the max cold pressure for which the tires have been rated. You can run whatever you like, but I'd never run less than what the manufacturer recommended or more than the sidewall stamped max. Running higher pressures will tend to wear the center of your tire out faster, depending on tire, but will also increase fuel economy slightly and cause the sidewall to flex less during cornering.

I played around with tire pressures a great deal on my WRX, and I can tell you from experience that it can make a huge difference in how the vehicle responds. Anybody who has done autocross or track time will attest to that. Of course, a RX350 is not an autocross or track toy, but the principles of vehicle dynamics are transferable.

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Agree with above statements - run 35psi in my RX. Also keeping up the air pressure helps protect the rim(s) in the event a nasty pothole suddenly appears.

And in this discussion we should not forget the annoying low tire pressure sensors/warning lights on the dash that activate if any of the tire pressures (including spare) fall below the programmed threshold. :(

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  • 2 weeks later...

I too run the tires (now Bridgestone Alenzas) at 35 psi cold (replaced Michelin MXV4's this past week). I like to have a little more road feel than what 30 psi gave.. Although our Lexus is unlikely to repeat the Ford Explorer/Firestone disaster, I have taken those lessons to heart and always keep tire pressure slightly above the car placard but always below tire max. These Bridgestones have some ridiculous 51 psi max rating. My 2 pesos

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...you can inflate to the max pressure shown on the tire sidewall...

OMG - NO!!! This is like saying a car will go 120 because the spedo goes that high.

As stated above, that is the maximum pressure for the tire. The door will list what is recommended for the car. I wouldn't go up at all, but I'd guess 5# isn't terrible. Not sure what it would do to the wear pattern, tho.

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...you can inflate to the max pressure shown on the tire sidewall...

OMG - NO!!! This is like saying a car will go 120 because the spedo goes that high.

It is nothing like saying the car will go 120 because the speedo goes that high. The tire is stamped with a max cold pressure after being tested by the manufacturer. In most cases it would be silly to run pressures anywhere near max. Having said that, I ran my the stock tires in my WRX at max during autoX because the sidewalls were so soft. They still didn't grip well, but at least when they lost grip it was more predictable and they provided better feedback.

Different tire mgfrs have different max PSI for the same size tire. I experimented with the door jam numbers, but I prefer a smoother ride, so I run the tires a little lower than what's on the door. I don't mind trading off a mile per gallon on the MPG for a smoother quieter ride. The cornering, traction, "on track" performance is a non-issue for my wife's car. If I ran the tire pressure at max according to the sidewall, it would be like riding on skate board with metal wheels!

Careful, particularly in AZ where the blacktop can get extremely hot. Lower pressures means higher temperatures - this can result in a blowout and is the reason we have these automated nanny tire meters mandated in all of our cars now.

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  • 3 weeks later...
My 08 rx350 recently returned from the local dealership with all tires at 36 psi. cold. I checked the door panel and and they are supposed to be at 30 psi when cold. Bad dealership or am I missing something?

Thanks

Tires are good for 44 psi... and saves fuel... try that. Why not make your 350RX get excellent mileage?

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