unless you run the diff without oil it is very strong and should last 500000 mls.it is almost 30% better ratio[for accel] so at say 100mph constant speed i would expect about 20% more fuel usage from a 12 cyl engine.

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David S Poole
European Performance
Dallas, TX
4696880422

"Fortune favors the prepared mind"
1987 Mercedes Benz 420SEL
1988 Mercedes Benz 300TE (With new evaporator)
2000 Mercedes Benz C280
http://www.w108.org/gallery/albums/A...1159.thumb.jpg