I'm about to get a set of spare tires for the RT12. Right now I've got the Continental VMAX on it, 235's in front and 325/30/19's in back, on the OZ's.

At this point, my choices are down to:

PS2's 345/30 in back or MPSC's 325/30 in back (easy to get the front tires in the original sizes with either tire).

Some questions for y'all:

1) What kind of mileage can I get out of the MPSC's?

I've got MPSC's on my GT3 and the insides grooves are totally gone after around 3,700miles/6000kms. But the car is driven on the track, whereas the Ruf won't be doing much track duty at all, if any. So assuming purely street miles, how long can I expect these to last?

2) Is it ok to use the PS2's even if they're not "N" rated for Porsche?

The PS2's in 345/30 are "C" rated for Viper. Will that make a real difference for street driving? The Ruf does a lot of high speed running, but not a whole lot of heavy cornering...

(BTW, i know the 345/30's are marginally larger in rolling diameter than the tires i've got now... but its about a 1.7% difference, which I believe is acceptable)

Thanks in advance!
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I will use the MPSC's the GT2 uses for my track tyres (same sizes as current contis) at the moment I use them with the narrower rear wheels of 11.5" and I can honestly say they change the cars handling dynamics considerably for the better. Also the N rated 997 Gt2 MSPC tyre has been redeveloped by porsche by adding extra grooving amongst other things.

The Ps2 will be too tall and affect the ABS settings (warning lights etc.) the 30 aspect is a ratio of the cross section of 345 so in reality they are much too tall..I made that mistake before buying narrower wheels to accommodate 305/30 MPSC which i have been using for about a year.

I keep the contis for cross european high speed driving.

Hope this helps,
all the best

 

Hey man, thanks for the inputs.

However, remember that the car also comes with the 355/25 Pirelli's, which were an option from Ruf.

The difference in size between the Pirelli's and the Conti's is more significant than the difference between the PS2's and the Conti's. Take a look at this computation:



So the PS2's are slightly larger than the Conti's, and the Pirelli's are slightly smaller. But the Pirelli's are smaller than the PS2's are larger (1.74% vs 2.59%). Wouldn't this result in problems with the ABS as well? I don't think Ruf would actually recalibrate the ABS to suit the Pirelli's vs the Conti's...

 

If you are going to boost up the rears .. I believe the fronts need to be adjusted to maintain balance. IMO, I would just run GT2-spec sizes: 235/35 and 325/30.

 

Dude all I know is that I actually fitted the PS2 in that size on my wheels and I had christmas tree lights from the abs etc so it obviously can't cope with more diameter than the conti's.

go with the 997 gt2 mpsc

 

Got it. Will do just that then! Thanks for the advice man! Cheers