Here is some comparitive weight data for the stock parts in my MC and a 92 S4 vs JE pistons and Carrilo rods. (Thanks to Michael Pederson for the additional data):
ITEM Custom weight(grams) STOCK(grams)
rings Total Seal: ???? 29
5kt MC Piston
81 stock 82 custom 		380 384
S4 AAN pistons
81 stock 82 custom 		279.5 355
5kt MC Wrist Pin 120 129
S4 AAN Wrist Pin 87.5 106.5
S4 AAN Con. Rods
custom steel?/titanium 		533.5/415!! 657


Carillo(?) Titanium rod for a vw gti vs the stock rods for an S4 AAN

custom JE Pistons compared with the stock Mahle pistons.


Note the large cut in the top of the piston... almost wish I would have made it not quite so deep so as to raise the CR just a little bit.



JE piston tops.. note the dish JE piston side.. less material than stock
a few small differences here pistons and rings finally showed up