Michelin PS2: What pressure?

[jonas21]

Hello,

i just ordered a set of new Michelin PS2's*. As i havent driven these yet (but heard pretty good things about them) i wonder what pressure these need on the RS6.
Almost all tyre manufactures recommend increasing pressure when driving at speeds around 300km/h thus i wonder what Michelin recommends.

Conti says +0.5 bar (7.5 psi) for the SC2....makes 3,3 front and 3,1 rear.

* Michelin Pilot SPORT PS2 255/35 ZR19 96Y EL

[JAXRS6]

Tire companies don't recommend tire pressures, at least in the US. They specify a maximum (50 psi is stamped as the max on my 18" PS2 sidewalls), but recommendations for actual tire pressures to be used are made by the auto mfr. In the case of the RS6, Audi recommends 36 psi all around with a light to medium load and 42 all around for heavy loads, as displayed on a permanent label affixed in the door frame of the right rear door.

Extreme pressures, high or low, can result in uneven tire wear. That happened with my first two sets of tires, both Pirellis, but not with my PS2s (now on second set). One reason may be that after the uneven wear occurred, I began to pay more attention to wheel alignment, which also affects (un)even tire wear. And, of course, low pressure can worsen fuel economy.

Most of my driving is solo but personally I prefer 40 psi; seems to lighten up handling a bit with no sacrifice in traction or ride quality. Others have different preferences. This was discussed a couple of years ago, if you care to do a search.

[jonas21]

Hmm 40psi sounds OK for normal driving without high speeds. However i am mostly going for max thus i need higher pressure.
Wetterauer (who did the tuning on my RS6) contacted Continental regarding the SC2 and they faxed them a paper which stated the above values. As the RS6 (stock) is limited to 250km/h i dont think Audi will give any good info on this...

[Hy Octane]

36 psi is the minimum safe pressure for the car. If you drive it that low, you are not getting the maximum performance ..
I have mine at 42 cold all round and this provides sufficient sidewall support to prevent roll-under.

[Lateknight]

In the case of the RS6, Audi recommends 36 psi all around with a light to medium load and 42 all around for heavy loads, as displayed on a permanent label affixed in the door frame of the right rear door.



..or found on the inside of the fuel filler flap.

I would advise you stick to these figures on the sticker as long as your using Audi approved size and brand tyres (a list of these is found in the handbook / owners manual.)

[Hy Octane]

Once again all.. the numbers on the sticker on the gas cap are the minimum allowable for the weight of this car..

[Lateknight]

The heavy load rating on the sticker is also for meant for high speed driving (as stated in the handbook). Which, as you correctly state, is why you obviously run 42psi. If you are talking about preventing roll-under you obviously ain't hanging around.
If your going to use your RS 'properly' use the heavy load rate.
If your going to 'pootle about' use the standard light rating, to prevent any adverse tyre wear.

[SoCal]

I have PS2s on my RS6 and generally keep them at 40 psi cold (2.76 bar). I vary it a bit depending on season (though in California there isn't that much seasonal temperature variation to worry about) and am kind of fanatic about monitoring tire pressure and condition and wheel alignment on all my cars. My RS6 usually has just me in it and an empty trunk, so extra weight not an issue, and I'm not doing extreme high speeds.

If you are going to be doing extended high speed runs in a warm climate, then your cold temp tire pressure should be lower to allow for the tires to heat up more during use. We don't hit those speeds in US so, absent track use, not really an issue.

You mention that you are using 96Y tires. Be sure those meet the heavy load requirement for the RS6. I run on Michelin PS2s that are 255/40YR18 99Y. The "99" in that number is heavy load. Tires, even at right size, that are 95 (and maybe 96) are technically insufficient per Audi specs. Heavy load matters especially if you will be at high speeds alot due to effect of repeated braking from higher speeds. This is not a light car.

[jonas21]

(a list of these is found in the handbook / owners manual.)

I wont trust the manual on these things as its likely over 6 years old. Tyre's have changed since then.

I just found the tyres i ordered on michelin.de and they have a great tool for displaying suggested pressure.

[jonas21]

You mention that you are using 96Y tires. Be sure those meet the heavy load requirement for the RS6. I run on Michelin PS2s that are 255/40YR18 99Y. The "99" in that number is heavy load. Tires, even at right size, that are 95 (and maybe 96) are technically insufficient per Audi specs. Heavy load matters especially if you will be at high speeds alot due to effect of repeated braking from higher speeds. This is not a light car.

Thats absolutly no problem. My vehicle registration certificate says min. 96Y. No word on 99Y. I also checked the michelin website and they suggest 96Y on 19" and 99Y on 18".
See picture above. Suggested pressure for my tyres is 3.1 bar which eqals to 45 PSI.

[gjg]

RTFM - 99Y is for 18", 96Y is for 19" tires