Time is the one thing that often upsets the apple cart.
GM, and about any other manufactuer, has the " xxxx miles, or one year ..." clause in their warranty. Even the vaunted Amsoil products have the "25,000 miles or one year" clause on many of their products.
The reality is that oil has no idea how long it has been in the crankcase. The things that degrade oil are corrosives and contamination. If you drive low mileage per year, but each trip is of decent length (to fully warm the engine and fluids), it is quite possible to go well past the "or one year" mark.
However, for most people, including me, it's not worth the warranty risk to extend past the one year mark, to save the money of an oil change; the risk outweighs the reward. So, we change oil at one year, as a max. I personally only drive about 5k miles a year in my Dmax. I use Rotella 10w-30 year round, and change once a year, to comply with warranty concerns.
There was a recent post over on BITOG where a guy ran 5 years, for 10k miles, on just ONE oil change in his gas powered Tundra. He then did a UOA, and everything came back fine! That really blows away a lot of myth! Still - is it worth the risk? Not to most of us.
If you drive short annual mileage, your most beneficial strategy is to run a decent quality HDEO dino oil (grade: 10w-30 or 15w-40) (brands: Delo, Delvac, Rotella, Tection Extra, Premium Blue, etc) and quality filter (brands: A/C, Wix, Napa Gold, Baldwin, Purolator, etc) and just change oil once a year. For anything around 10k miles or less, this has been proven, by many UOAs, to be an excellent route. In fact, UOAs show that for lower mileage (less than 10k miles) dino oils provide just as good wear numbers as any "synthetic" out there.
Past 10k miles, synthetics, and possibly bypass filtration, are good things to consider. UOAs are a must past 10k miles.