Originally Posted by SamS
Well you'll can't have Increased Top Speed Limiter (840) without summer tires. And it is well known fact that Sport Line and M-sport cars have an extra cooler on the driver's side lower intake (where fog light would be) when they have summer tires. So the logical conclusion to be drawn is that option code 840 for Increased Top Speed Limiter adds the extra cooler.
Remember, sport lines do get fog lights.
The Msport doesn't, because BMW claims the US market needs the added cooling air flow supplied by removing the fog lighs.
Maybe that is what has you confused.
Yes, I already stated that to get the increased limit you have to have the higher speed rated tires.
And that's all the limiter is based on.
That "extra" cooler, I haven't read anything mentioning it.
There was an additional cooler added back on the E90 after the initial release of the N54, as they found it was needed.
But, that has nothing to do with the speed rating. It's the tires.
It makes no logical sense that you HAVE to have an extra cooler to go an additional 25mph.
The tires speed rating has a distinct impact on the speed limiter as your cars speed limit shouldn't exceed the tires capability.
This is not new to BMW. Even with NA engines BMW has offered the increased speed rating and it was based on getting the sport package, which came with higher speed rated tires, no additional cooling needed.
Again, do you have any actual reference information showing that this "extra" cooler exists only on cars with the raised limit, please post a source.