Carbon fiber roof or moonroof?

[boss2k]

Originally Posted by CanAutM3

It would defeat the purpose entirely. The whole point of a CF roof is to save weight.

How much weight 50 lbs , is that really significant weight saving?

[Arcades]

Originally Posted by boss2k

How much weight 50 lbs , is that really significant weight saving?

Yes?

Adding that much weight on top of your car is a difference when it comes to track. It's like adding 15+ pounds to each side of your car by getting heavy rims. You would feel it during turns.

The less weight you have the better your car will do at it's limits. Granted most everyday driving you probably wouldn't feel it, but that is not what getting a M3 is about.

When it comes to these types of performance cars, power to weight ratio matters. Why do you think FI-R and R101s are so popular? or why the AMG C63s does not generally out run a M3 stock to stock despite having a big hp advantage?

[CanAutM3]

Originally Posted by boss2k

How much weight 50 lbs , is that really significant weight saving?

50lb that high up will increase weight transfer during cornering and reduce grip.

Now, does the 50lb just by itself make a huge difference? The answer is no. However, it is the incremental weight savings that add up to make the difference.

What is the point of making a fancy and expensive CFRP roof and roof bow to save a ~10lb pounds and then add 40lb of sunroof and related mechanicals. My guess BMW figured that those that want the sunroof don't care about the weight so much so no need for a CFRP roof.