GM’s Live Green, Go Yellow PR campaign to greenwash its ethanol efforts is off to a roaring start — namely, “overwhelming demand” quickly exhausted its supply of free T-shirts. But never fear: “Please try again later — they’ll be back soon!”

The campaign tries to spin some good news out of GM’s monumental financial woes. GM has already sold 1.5 million “flexible-fuel vehicles” — principally those that burn an 85% ethanol mix — largely thanks to a loophole in CAFE fuel-economy regulations that grants FFVs “extra credit.” GM’s truck-heavy vehicle mix has needed all the extra CAFE credit it could get in recent years, so it’s on track to sell 400,000 FFVs in 2006, and all but two of the 11 FFV models are trucks. GM and Ford spent recent years riding high on booming truck sales, using loopholes to barely stay inside CAFE regulations without having to actually improve fuel economy.

Today, GM’s entire worldwide car-making operation is bleeding cash; all of its earnings come from GMAC financial services, an operation that GM is looking to sell to raise cash. Meanwhile, the autobuying public looks set to crown hybrid leader Toyota as the world’s largest automaker, possibly within the next two years. And GM’s “Go Yellow” trumpeting aside, E85 has yet to make even a small dent: Only 550 filling stations nationwide sell it, one for every 400,000 cars on America’s roads. (Even here at the edge of the Corn Belt, I’ve yet to see a single station that sells it.)

To add insult to injury for GM “flexfuel” truck owners, a switch to ethanol will make their gas guzzlers guzzle more: Ethanol contains one-third less energy (in BTUs) per gallon than conventional gasoline, which means many more trips to one of those lucky 550 filling stations.