Warning to GM Owners

Apparently the cause of the failure of the fuel gauge sending unit is because sulfur in gasoline is attacking the sending units. The service writer showed me the sending unit, and where the contacts had turned black from sulfuration of the metal. GM has apparently sent out a technical advisory to dealers about the importance of using GM's fuel treatment every 3000 miles to protect the sending units. Corvettes seem to be especially prone to this problem--and wow, is it expensive on a Corvette to have done!

UPDATE: A reader tells me that GM's fuel treatment is really just Techron's fuel treatment, with a GM label and twice the price. I look here, and even the weird shape of the bottle is identical.