I have a 05 MCS with 205/45 ZR17. The recommended tire pressure on the sticker says 38psi. Other threads on NAM consistently say 35 or 36 psi.

Does the 38psi relate to the original run-flats?

 

I believe so, I inflate mine to 36 psi. It's better to be in the middle than too high/too low.

 

Are you talking about the sticker on the driver's door jamb? My 2006 'S' has two stickers there - a large white one that recommends 35 psig, and a smaller yellow one that specifies 38 psig for speeds over 100 MPH. I have the same stock tire size as you (205/45-17), although mine is a convertible, so it might have different pressure recommendations as a result (although if anything, I would think that the heavier convertible would need *higher* tire pressures, not lower.

 

I run 38 all the time.

 

Only one sticker that says 38 psi. No mention of speed.

 

Here are the stickers I was talking about on mine (35 psig on the white one, 38 psig on the yellow one):



So yours just has the large white sticker, and it recommends 38 psig? Or do you have a different sticker entirely? The differences between our cars may be a 2005 vs 2006 thing, or a coupe vs convertible thing.

 

Only have the large white sticker which says 38psi. Your stickers seem to make more sense.

Thanks, now I'll feel more comfortable when I drive over 100mph

 

My car came with run-flats and the only specified pressure was 38 psi.
I believe 38 is the normal psi for the run flats.
I now have non run flats and I use 38 in the front and 36 in the rear.

 

I had the run-flats on mine from the factory as well (in fact, I think *all* of the first-gen 'S' models came with run-flats), and my sticker still recommends 35 psig except for 100+ MPH operation.

I'm beginning to wonder if the lower pressure recommendation on mine is because it's a convertible.

 

The tire pressure varies some depending on exactly which model it is--hardtop vs convertible, and Justa vs. S vs. JCW. See the owners manual where there are lots of pressure tables depending on your "citrus" flavor. I notice some of the replies are gen 1 and others gen 2 as well.

The sticker pictured is the one now standardized by NTHSA rules--white background, black lettering w/ some yellow and red. Standardized both in terms of content and (driver's door jamb) location. The underlying rules were driven by the Ford Explorer rollover debacle and in general cause manufacturers to push pressures up to higher levels to support greater vehicle loads. The manual provides better info here in general for most cars.

 

I think I'll try your 38/36. I wanted to ask how you like it, but if you're running that setup you must like it.

 

It's nice for a change to be able to tweek the car without spending any money.

 

When I ditched the RFT's, my new tires felt too squishy at 35psi. I went up to 38 and found the sidewalls to be stiffer, and the handling sharper, better all around.

 

not to muddy the water, but my tires will show approximately a 2 pound pressure increase from normal to high speed, and a 3 pound jump from cold to fully warm (as in competition)

in my experience +/- 2 lbs is driver preference. the tire isn't that picky...

wanna pyrometer?

:-)

 

For daily driving, I've NEVER followed the recommended pressures on the sticker (for conventional All-Season or Summer tires). At 38 PSI for the 2600-2850 lbs Mini, it's just too bumpy. I'm running 33-34 F / 27 R (cold) on the current Dunlop Direzza DZ101. The rear has a lighter load than the front and being a FWD car, I don't understand why manufacturers recommend such high PSI for the rear. I've done the same on my VW/Audi FWD vehicles with no negative effects on wear.

My guess is the Gub'ment requires high PSI as a safety measure since how many drivers actually check their tire inflation on a regular basis.