GM is going aluminum

maxwell11 wrote:
gm will be making their trucks with AL bodies following ford to get the weight down for fuel mpg goals I guess.
Will cut the weight, but wonder how it will hold up in the real world, salt, road grime, etc: over the years.

Wonder if the engineering dept has any old school logs left from back in the day:
Do you remember GM trucks back in 1973-1975, they changed something in body protection and some bed fender wells and cab corners were rusting out in 6 months.

I stated that frames usually are not made of aluminum, but I owned a 2000 Chevy Impala that used a thick aluminum K-member. We really liked the car, great mileage.

The K-member merited an unofficial recall; it went back for a simple mod to prevent a clunk when turning. I assume something worked loose or cracked, but we didn't clunk yet. The "new" chassis replaced the aging Lumina sedan that year and was a derivation of an earlier Buick chassis. The Buick had some front suspension rust problems and perhaps went aluminum partly for that reason in conjunction with the continuous GM program of weight savings.

I think the most exotic thing on the 2000 Impala was an intricate cast magnesium dash bulkhead behind the firewall. The thick, bulky piece added a great deal of stiffness to the now squeak-free cowl, which is partly why the unibody could handle high powered pursuit V-6's and even the torque and bulk of a V-8 in future years. Of course the magnesium added a lot of adequate stiffness for no weight increase over adding copius room-robbing steel sheetmetal webbing.

Styled like a Mercedes sedan, one could buy two Impalas for the price of one Mercedes, thereby outlasting them for the money. As always, prestige was another story... "Oh Lord".

Wes
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