[///M1]

Originally Posted by cpippolo

3704 lbs is official M3 couple weight from website. Presume the 3300 lbs for 1M is on the same basis. 135i with sunroof and manual trans is 3373. Had heard that the 19in competition wheels are actually lighter than the 18inchers for the M3. Non-runflats I believe are signfiicantly lighter than runflats. No sunroof should save about 45lbs. Some of the reviews suggested that some of the body panels were plastic (composite I think?), which should save weight. The only weight addition is the LSD, right? Don't know what that weighs, but 3300 lbs overall seems in the ballpark.

Well, I love to be able to see and believe it. I just wonder where the net weight savings come from. Here is a quick back of the envelope calc:

1. Rims: let's call it even, although me thinks even with the relatively light for 19" wheels, the M3 Comp 9/19 fronts with the 10/19 rears will outweigh by a few lbs the stock 7.5/18 - 8.5/18 setup.
2. LSD - whatever it weighs, it adds lbs
3. Exhaust - ditto. A dual setup (granted a one sided with an extension) should weigh more than the 135i's one-sided
4. Brakes - even though the 4 rotors are cross drilled, they are much bigger than the stock 135i. Unless there are some savings on the caliper front, I would say they will be a net weight gainer
5. Tires: yeah, while RFTs are heavier, keep in mind you are going from a 215/40/18 front and 245/35/18 to 245s/265s in a 19" configuration. Looking on Tire Tack's website, the RFTs are 24lbs up front and 26lbs in the rear. The PS2s in the 19" configuration are 23 and 25 lbs, respectively. So that equates to a mere 4lbs savings. However, it will likely have the ///M mobility kit in the trunk, so at best this is a wash.
6. Sunroof delete - call it 45lbs. Although I have to say, I am not sure BMW will have this standard in the US, many folks consider this a vital option here (although on a car like this I agree it has no place).

If you add these up, I see a net increase if anything, or optimistically at best flat/no gain. If indeed it is marketed to be 3300 then they must have found a way to shed some 73lbs or more. Maybe fenders are light weight material, maybe less sound deadening material inside (unlikely). We shall see, I like the 3300 figure but for now can't figure out how they arrived to it.