Here is the Edmunds.com review of the Pontiac G8GT and their note regarding oil:
Not only did our 2008 Pontiac G8 GT provide just under 36,000 trouble-free miles, but it did so under sometimes stressful conditions — which resulted in a $684.67 bill for new rear tires.
But for all that, our G8 required only three oil changes. That's three, not the 12 oil changes that might have been required back in the days when you had to change your low-grade mineral oil every 3,000 miles. We just let the Pontiac's electronic sensors determine when the oil had to be changed. And since the cost of each oil change averaged $35, we saved a lot of cash, not to mention a lot of time, by listening to the sensors. Also we saved a lot of oil, using 27 quarts instead of 108.
"Inside Line," you're saying, "my daddy taught me to change the oil every 3,000 miles. He'd die and then roll over in his grave if I told him about a 13,000-mile interval between oil changes. Got any proof this works?"
Yes, we do! Just before the G8's final oil change, Senior Consumer Advice Editor Phillip Reed sent a sample of the G8's oil to Blackstone Labs for analysis. The sample came back good on all fronts, but just barely so. Turns out that the G8's sensor was correct, and so 13,000 miles proved to be the perfect mileage to ensure that the oil's goodness had been used to its fullest, since there wasn't much life left in it. But another lesson here is, when the service light turns on, get it done fast, because the oil is done.
