Other Category problem
2007 Other GMC Models 6 cyl Four Wheel Drive Automatic 5,000 miles
I have a 2007 Hummer H3. I bought a service contract with the dealer in Bellevue, WA to change oil/filter and other scheduled maintenance over the first three years. My question is this - the dealer started out using Penzoil 5W-30, then switched to Castrol GTX 5W-30, and last week switched again to Chevron 5W-30. I complained about it, and the Service Consultant said that it doesn't matter since all these oils have the same spec. Intuitively, it doesn't sound like a good idea to me, because each of these oils has a little bit different composition and additives, and they are being mixed during each oil change. Please provide some factual data.
Monday, February 18th, 2008 AT 8:10 PM