Anyone know why the 328i has a 66lb difference from man to auto, but the 335i only has an 11 pound difference? Is the 335i's manual beefier?

Don't the 335 & 328 use different autos?

the 335 and the 328's auto transmissions are completely different. The 335i uses the ZF tranny, while the 328i uses the GM's tranny. Different company, so that's why there's a different in the weight.

And your comparing stats of the entire car. The 335 comes with more options...so you can't assume what is lighter in that figure.