Isn't everything "aftermarket" now Dave? You can buy an alternator that says Honda on it but it's made by Hitachi which since around '97 is manufactured in China. It seems stuff made in China that is meant for export is made from inferior materials and assembled by little kids who didn't have the talent to be acrobats or gymnasts. What year was your Suburban John? I'm looking to see if there are any Chinese made alternators out there that get the kind of mileage your Suburban got. The problem doesn't seem to exist across the board with later model vehicles though. It seems to be as Dave indicated that it is the aftermarket high output units people are putting in their 1500s. Could it be that car and bike manufacturers require their parts to meet certain specs while the low priced off brands have no such standards? I guess what I'm getting at is, is it possible that the budget units from LActrical and DB Electrical are nothing more that cheap knockoffs the Chinese are famous for?