ahhhh, yes, GM.
According to GM and their AWESOME Oil Life system, most vehicles only need an oil change every 15K miles.
But, also according to GM, their vehicle can burn a quart of oil every 1~2k miles....
Which, if we use a 5.3 engine for example, means it's completly empty of oil at 12K miles...... running up to 3K miles on oil FUMES....
Yeah, I think I can advise my customers a LOT better than GM as to vehicle maintance.....