I am sure this is a really old question...but:
I haven't yet had my 2002 X50 at the track, but plan to attend a DE this fall. Use my new 19"s with new PS2s or OEM 18"s with Pirelli PZero with about half tread left? Better to wear out the 18s or use the grip of the new 19s?
Thanks.

 

use the 18s and pick up a set of r compounds. this is the best, and safest thing you can do. you need good grip and good traction with a powerful, heavyish(no offence) car. that looks like a beautiful car from the avatar and I am sure you want to keep it that way. also since the pzeros are half done the timing is perfect. btw, the consensus, regardless of tires is 18s over 19s for track . Next the question is which rcompounds? I like toyo and yokahama personally, and you can drive them to the track no problem.

 

+1 on Turbodan's comments. Stick with the 18"s, there's way more rubber selection, and cheaper too.
The Pirellis are prime at 1/2 thread, especially this being your first DE and all. If you later get serious about it, get another set of wheels (I have three so far, thinking about getting a fourth set), and get some cheap tires (Sumitomos, Yokos, look around) for "regular" DE's (and to use as "wet" tires) and some Hoosiers R6's or some other R compounds for timing.

 

Is this your first DE or first in this car?

First DE I'd say go on the 18s with the tyres you have, just be religeous about checking pressures after each session, don't let the get over about 40psi front/rear hot. (You will have to take out quite a bit of air from the rears cold to achieve this, guessing starting at about 35psi cold).

You'll want to switch to R compounds eventually, but not right away. When they lose grip it is with a lot less warning than street tyres. The OEM 18" turbo twists make great track rims. Pretty good assortment of tyres for them.

 

Have to agree with Boss. Use up your Pirellis to learn on, then move to R compounds when you start to overdrive your street tires. Save your 19's for street and winter driving. 18's are better for the track. Tire pressure is crucial.

 

+ 1

 

+1 on above, I have two sets. Very strong, although quite heavy!!

 

couldnt have said it better. really no reason for 19's at the track. heavier usually and tires cost way more. unless you need to fit HUGE brakes in them stick with the 18's you have a long way to go!!

 

Thanks for all of the advice. First DE in this car, but it's been a while. I liked Land Jet's comment about saving my 19's for winter driving, I live in Minnesota, winter driving in this car is only in my imagination! Will plan to wear out the Pirelli's first time.

 

I used to live in Chicago and driving the turbo in the snow with winter tires is a blast!!! You have to try it at least once.

Lane