But all of the posts about the AFM/lifter issues have me a little worried, and I was thinking about changing to at least a synthetic blend motor oil in my 5.3L LC9 engine. Up until this afternoon, I would be a little leery about running a full synthetic for fear of oil leaks, something my last GM vehicle (96 Impala SS LT1 running Mobil1) had a bad problem with.
To that end, I was doing a little internet research this afternoon during the NASCAR red flag, and was surprised to see a reference to a new 2011 GM oil requirement called "DEXOS1". Here is what it says, and it sounds pretty strict:
New Oil Spec For 2011 GM Vehicles
HOUSTON, July 2010General Motors is introducing Dexos1, a new global engine oil specification for gasoline and E85-fueled vehicles, in all 2011 model year Chevrolet, Buick, GMC and Cadillac vehicles. Basically, the company requires that every owner of these vehicles use an oil that is Dexos1 approved at every oil change. It also encourages owners of pre-2011 GM vehicles (except diesels) to use a Dexos1-approved oil as well, as the new specification offers several advantages over previously available motor oils, including improved levels of:
GM says these will result in improved engine life and performance.
Therefore, every owner of the GM vehicles mentioned new and old should be pleased to learn that new, next-generation Pennzoil Platinumฎ full synthetic motor oil is fully Dexos1-approved in the popular SAE 5W-30 viscosity grade.
This would seem to suggest that GM is switching to a full synthetic oil requirement in 2011, and will require proof of such for warranty work. WOW It makes one wonder if GM is tired of fighting valvetrain problems and are just mandating synthetic oil now to try to help them with warranty work. If that's what GM is doing, now I'm thinking about full synthetic as opposed to a synthetic blend, I guess.
Do any of the GM Techs on this forum have any info on this new DEXOS1 requirement from GM?
I don't tow very much (horse trailer) but temps here have been known to vary from 15 (F) degrees below zero in winter to 115 (F) in summer, and I do a lot of stop and go driving in town. My oil change monitor is calling for changes between 5000 and 6000 miles, but I change it every 4000 with Pennzoil conventional and ACDelco (PF48?)filter. Frankly, I wouldn't mind running a full synthetic oil, for peace of mind that I'm doing the best I can to keep it sludge-free and avoid AFM/lifter issues. But I sure don't need any oil leak hassles like I had with that Impala SS! My Dad is a Ford fan and says that it's a well-known fact that GM engines make their oil dirtier a lot faster than Fords do. That's news to me, but he usually is right-on with anything mechanical. Is there anything to that?
Do any of you GMT900 (2007+) owners have oil leak problems while running full synthetic oil?
Thanks in advance for any replies!
Edited by Maverick Z71, 01 August 2010 - 08:25 PM.