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      11-14-2012, 09:11 PM   #141
Major General

Drives: 340i M-sport AT
Join Date: Mar 2006
Location: Chicago

iTrader: (1)

Originally Posted by SamS View Post
I think when you get the summer/performance tires, it triggers option code 840 for Increased Top Speed Limiter, which should include an extra cooler of some sort. Which is required for the PPK?

The thread you pointed does speak about the added cooler, but it references that all Msports get the cooler not just the ones with summer tires.
Even with the added cooler, I don't see how that would affect top speed limit. Cooling is more important at lower track speeds than at high highway speeds where there is plenty of airflow.
It makes sense that the speed limiting factor is the lower speed rating of the AS tires.
H rating is good for up to 130mph.
V rating is up to 149mph.
W rating is 168mph, and then there is Y for 186 and 186+.
To have the 155mph limiter the tires have to be at least W rated.
The AS tire options are V rated, thus they have to have a lower speed limiter.

If anyone finds anything more on this cooler having relation to the speed limiter please post.
I'm very interested in knowing if there is a relationship and why.
Please post if you find something on that.

Last edited by RPM90; 11-14-2012 at 09:34 PM.