Mobil 1 oil...GM4718M
#1
Le Mans Master
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Mobil 1 oil...GM4718M
I find this interesting... The GM spec GM4718M is on the mobil 1 5W30 qt. containers. It is not on the mobil1 10W30 containers. However... On the Mobil web site, they state that 10W30 Mobil 1 oil does meet the GM 4718M spec. So if you use Mobil 1 10W30 instead of 5W30, the fact that the spec is not on the container AND the owners manual only recommends 5W30 could give GM a reason to deny warranty work.. Why would the spec not be on the 10W30 container when the product does meet the spec.?
#3
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Wal Mart Super Tech Syntethic
5w-30 says it meets Corvette & Viper standards but like Mobile! it's not on the 10w-30 bottle. I guess because the manual says use 5w-30 . But man it's hot here in the soulth and I have never used 5w in my 58 years.
#6
The GM spec also includes fuel mileage as part of the requirements - 5W30 is a bit better (like 1-2 mpg) for efficiency. Of course, your motor is toasting nicely...
I'm now thinking the hot ticket will be the new extended life 5W30 (still with 5000 mile changes), and a new "stat and radiator to manage temps.
I'm now thinking the hot ticket will be the new extended life 5W30 (still with 5000 mile changes), and a new "stat and radiator to manage temps.
#7
Le Mans Master
Originally Posted by Moval49er
The GM spec also includes fuel mileage as part of the requirements - 5W30 is a bit better (like 1-2 mpg) for efficiency. Of course, your motor is toasting nicely...
At cold start the 5W-30 has minimaly lower viscocity (56 cSt versus 62 cSt) and after a few seconds the viscocities will not be usefully different. At -10dF the thinner 5W-30 might enable starting a fraction of a second faster than 10W-30.
Running hot these two oils are also equivalent with HTHS numbers of 3.08 (5W-30) and 3.17 (10W-30), and both are a "little thin" for track use. RedLine and AMSoil and a couple others have xW-30 oil formulations with HTHS numbers in the 3.6+ range and are better for this application.
The 1-2 MPG differences are when compared to an oil with an operating viscocity of 14 cSt and a cold startup viscocity of 90-100 cSt--like any general 10W-40 or 5W-40.
#8
RedLine and AMSoil and a couple others have xW-30 oil formulations with HTHS numbers in the 3.6+ range and are better for this application
#9
Team Owner
I looked at all the Mobil One synthetic oils and the only one that is certified is
5w/30 . The extended versions do not meet the specs for the Corvette. Check each bottle and that oil is the only one that mentions this 4718 code.
#10
Le Mans Master
Originally Posted by NEO1
Amsoil has recently lowered the HTHS numbers down to where Mobil 1 is now, which is 3.2. They gave in to CAFE and fuel efficiency.