4718M Spec.

[heavyhitter]

So what exactly qualifies an oil to meet GM 4718M?

My thoughts is that GM wants it to be a synthetic oil to even meet the spec. What if a dino meet the criteria but wasnt "synthetic" so is it automatically disqualified?

Also of the brands that "meet" the spec they are all 5w30 or 10w30 does that mean oils of different viscocity did not "pass" in other weights ie: 0w30?

I notice that Mobil 1 is "approved" in 0w20,0w30,5w30,10w30. Does that mean they M1 was the only one good enough? I doubt it and it sounds dubious. I can see the M1 approval thing because M1/Corvette are in cahoots.

I would like to know more about what makes the 4718M so special and why would a dino not meet the spec, other than marketing hype.

 

[buster]

It's a high temp wear/deposit test.

At the time GM created the spec, Mobil 1 met it. GM needed a lubricant that could handle high temperatures.

 

[Johnny]

Found this info from a GM site:

Here’s the answer from GM Powertrain:

“GM4718M is General Motors' High Performance engine oil specification. Oils which meet GM4718M tend to be made from synthetic base stocks, so it is often referred to as a "synthetic" specification.

“However, not all oils, synthetic or otherwise, are capable of meeting the stringent requirements of GM4718M. Only the oils listed on the GM4718M Registered Products sheet have proven their performance to the specification.”

- Thanks to Matt Snider, GM Powertrain

Most synthetics mention GM 4718M in their list of claims; that's the unique spec created by General Motors for Corvette oil. It's a high-temperature requirement that tolerates less oxidation (thickening) and volatility (boil-off) on a standard engine test called Sequence IIIE, according to engineer Bob Olree of GM Powertrain.

 

[heavyhitter]

I can buy the hi temp spec, since synthetics tend to usually have a higher flash point.

I have no doubt that many conventional oils would pass the depost and wear test just as well.

I would love to find actual data showing which oils supposedly failed and why.

I have looked far and wide to find these answers but come up with nothing. Personaly I feel that they are selling you a high dollar car so its a ploy to make teh buyer feel good about themself to say say "hey this is a special car so you need special oil". If the OCI is like 10k on the car then I could see going syn. I use synthetics and Im not bashing them. I am just sceptical of all the "OEM specs" these days.

 

[bodeh6]

This is how Quaker State explains passing 4718M

 

[heavyhitter]

The Quaker state adds for the 4718m just sounds like the ILSAC GF4 Sequence III test. How ever I think GF4 runs the car for 100 hours at 300 degrees wich seems more stringent than the 60hr at 300.

 

[GMBoy]

Originally Posted By: heavyhitter
I am just sceptical of all the "OEM specs" these days.



No need to be skeptical. In today's automotive world with ever increasing performance and fuel economy goals the OEM's have to rely on everything that they can to reach these goals. Motor oil is a key player in helping OEM vehicles maintain emmissions standards, fuel economy standards, etc.

 

[casper]

no oil cooler = need an oil to handle high temps, hence 4718M

 

[Gene K]

Less Oxidation
Less Volatility
Less High Temp Deposits

If you want to know the exact test parameters you will have to purchase a copy.