While intervals are often longer than we are used to with the oil life indicator, the Onstar amount of 13k is like a starting point. You will see it rapidly count down as you drive. On average 4-6000 is the max you would end up with. The first time I saw this with my Sky I too wondered and discovered this info
Well I personally would not go 10,000 with this engine. The OLM should have been tested on the engine and it would have been done with conventional oil, and the EPA estimates done with conventional oil. If anything, people's MPG have done down and issues have gone up since putting synthetic in. If GM saw this much fuel in the oil I would imagine they would have done something about it. over 1% is absurd. I put convnetional oil in and will see if things improve. I plan to do a sample with 1500 miles on it and another at 5000 miles when I change the conventional. If that analysis comes back good I will keep conventional in for longer intervals.
If someone was insistant on using synthetic and staying with 5W-30 (since the manual says it has to be 5W-30) I would get the European spec 5W-30 Penzoil. Its pricey, but higher viscosity, hopefully keep fuel from getting past the rings, which is a completely common thing with high compression diesel engines. I combat blowby all the time with my diesel truck, and the more viscosity the oil maintains the better, it will seal the ring to the cylinder wall, for less blowby and less oil consumption.
I definately would not use a 0W oil, or lower than 30W when warm.
A quality full synthetic would probably be fine for 10,000 miles, but I would never trust the usual off the shelf oil filter to last that long before either degrading or getting clogged. I do my changes in 5k intervals..
Do yourself a favor and change it every 5k, cheap insurance. No way would I go 10k. Oh, and take a few seconds to open the hood and check the oil level periodically between changes. You'll extend the life of an engine to almost forever by doing that.
Being a DI-- for now- stick to about 5000 intervals at the most.
I have a 2010 3.6 DI- and am sticking to 5000- on dino oil.
But I will say- I do run up to 11,500 mile intervals on my 2003 Trailblazer (inline 6)- using the OLM.
No issues with that car- Its nearing 161,000 and runs rappily. Using the same dino oil used in the DI- Valvoline Conventional.
A forum community dedicated to GMC Terrain, Chevy Equinox, and Cadillac SRX owners and enthusiasts. Come join the discussion about modifications, classifieds, troubleshooting, maintenance, reviews, and more!