ken987

Hi,
We got rid of our run flats and bought new tires recommended here. We have a 2003 SC430 and the tires say max pressure 51lbs... It's been a while for us so we are not sure what level to fill them at. Do we do the recommended max? Or is there a better option? We used to live in New England and we now reside in Atlanta so we didn't know if the climate difference would be a factor. Any advice on tire pressure is greatly appreciated.
Thanks in advance.

mandyfig

33 psi on RFT's when running speeds up to 120 MPH.

Refer to you tag on the Driver's side doorframe.

ken987

My apologies for not being clear.
We dont have run flats. We have regular tires. But on the sides of the tires it says 51lbs of psi MAX> This seems high to us?
Ken

sixonemale

We have the Michelin A/S Plus non RFT tires and keep them inflated to the recommended PSI of 33 or inflate them slightly over that to 34 PSI so that on cold days the TPMS lights don't get triggered. The PSI on the side of the tire is the maximum they can hold, not the recommended PSI specific to a particular vehicle. Perhaps there are some vehicles that have a much higher recommended PSI where this maximum PSI might be utilized, not sure.

OBP

Yes 51 is waaay high. Set it at 33 or 34 and you will be fine. I have regular non rfts too and i like to set mine a couple above the door jamb recommendation.

mandyfig

Same as everybody said: 33 PSI.

I run mine 34 psi. And check pressures every 2~3 weeks as I have my TPMS sensor de-activated.

kjcole

the door tag refers to the stock tires. Once you get away from stock, you should consult the manufacturer's recommended pressure for the load on that tire. All tires are not made the same (side wall stiffness, etc) so the recommended tire pressures will vary according to the construction and the load on the tire. This was really important for the rear tire when I was riding heavy touring motorcycles, and probably not so critical for our SC's. Nevertheless, don't be wedded to that door tag once you go to a different tire.

With that said, use the max sidewall pressure as an upper limit, and then play around for the best combination of ride comfort, handling, and wear. Lower pressures will yield more comfort but faster wear. Higher pressures will stiffen things up and reduce comfort, but reduce wear (barring overinflation). The manufacturers usually recommend a pressure to maximize comfort rather than wear, btw. Most tire shops send you out the door around 40 psi. I like somewhere in the middle.

I've got Conti DWS and settled on about 37 psi summer, and 34 when temps are around freezing. Totally a personal choice - but at the price of these tires I'll lean more towards maximizing longevity. At about 25K the tires are wearing beautifully (even and not as much reduction in tread depth as I expected).

Sorry for the long post.

kelly

mandyfig

Good information. I never ventured more than 34 psi on the SC. Now I will try 36 or 38. Once I read somebody here using 40 psi and I said that's too hard.

Best to experiment, yes.

grabber2

35psi on stock size, now I'm running 40psi due to lower profile 19" tire