dexos1 Gen1 and Gen2 are both very good, yet I wonder if the high temperature requirements of 4718M would be met with many of the current synthetic blends (some GroupII in there to oxidized rapidly).....This sums it up:
Originally Posted By: Ducman
Originally Posted By: NHHEMI
Originally Posted By: bubbatime
I'm not sure why they specified High Performance engine oil for your application (4718M is called the high performance oil specification while 6094M is the standard oil specification)
As you have noticed, only synthetic oils meet 4718M. It'll probably be fine to run the Dexos syn blend, but if it were my car, I would probably stick with the specified synthetic oil.
Edit: That is good news above about Dexos 1 being officially approved by GM for use in 4718M applications.
I am with you. 4718M is a spec that only a full synthetic can( could )meet. It was originally come up with as I recall reading for the Corvette due to heat issues( i.e. poor air flow and cooling ).
f I had a vehicle that was pre-dexos and it called for 4718M I would ONLY run a full synthetic dexos oil. I would not run a blend in that application.
JMHO FWIW!
Quite right.
The crux of the matter is that the dexos spec is deemed to be backward compatible.
The dexos spec replaces the older 4718M spec.
GM has never stated that the dexos spec is "superior" to the 4718M spec.
And yes, it's generally understood that the 4718M spec was at least best served by using a full synthetic oil.
It originally was always referred to as the Corvette spec, due to the elevated temps in service.
With the recent advances in oil technology, it's possible that the old 4178M spec "may" be met with some of the newer blends of oil.
