You crack me up!
Castrol 0w40
Le Mans Master
Joined: Feb 2021
Posts: 6,503
Likes: 4,351
From: Florida
2025 Corvette of the Year Finalist - Unmodified
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Replacing Oil With Gasoline - A Breakthrough!
Last edited by vette4fl; Jul 11, 2022 at 07:17 PM.
Race Director
Joined: Apr 2007
Posts: 11,152
Likes: 890
From: South Western Ontario
OEM oil no longer exists. Hasn't for years. Got to pick something else. And besides 5w30 isn't the best oil choice for track use because of the higher oil temperatures.
It's sad how many people actually think todays Mobil 5w30 is what GM specified for the C5 and claim it's the only oil that should ever be used because GM said so right on the oil cap.
It's sad how many people actually think todays Mobil 5w30 is what GM specified for the C5 and claim it's the only oil that should ever be used because GM said so right on the oil cap.
Le Mans Master
Joined: Feb 2021
Posts: 6,503
Likes: 4,351
From: Florida
2025 Corvette of the Year Finalist - Unmodified
2024 C5 of the Year Winner- Unmodified
2022 C5 of the Year Finalist - Unmodified
Early on I used shelf brands in my endurance engines, but later went with the boutique brands once I had more money and a lot more investment. Oh, and I wanted to finish!
15-50, 20-50 “ish” top of the line full synthetic is really worth it IMHO. Amsoil, RedLine, etc. Call those guys and I bet one will stand out for your needs.
I wouldn’t worry so much about the lower number (0-20). It’s not like a street car where you’re going to drive it cold, and you really should have a heating element inside your oil pan if you are running in a cooler environment. That’s not going to give you 200°, but hook it up to your generator for an hour or so and it will be over 100° before you fire up for your first heat.
Pro tip: Run the starter to build oil pressure before you light the engine. Get that warm oil into the bearings and you’re good to go.
Last edited by vette4fl; Jul 6, 2022 at 01:50 AM.
Drifting
Joined: Nov 2014
Posts: 1,979
Likes: 110
From: Switzerland
"I wouldn’t worry so much about the lower number":
exactly, and keep in mind that an 0w-40 oil is considerably thiner than e.g. an 15w-40 oil. actually, with the latest tech (ester/pao) a 15w-x can be a straight x oil without viscosity improovers to shear down (→e.g. redline).
exactly, and keep in mind that an 0w-40 oil is considerably thiner than e.g. an 15w-40 oil. actually, with the latest tech (ester/pao) a 15w-x can be a straight x oil without viscosity improovers to shear down (→e.g. redline).
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Advanced
Joined: Jul 2022
Posts: 51
Likes: 7
OEM oil no longer exists. Hasn't for years. Got to pick something else. And besides 5w30 isn't the best oil choice for track use because of the higher oil temperatures.
It's sad how many people actually think todays Mobil 5w30 is what GM specified for the C5 and claim it's the only oil that should ever be used because GM said so right on the oil cap.
It's sad how many people actually think todays Mobil 5w30 is what GM specified for the C5 and claim it's the only oil that should ever be used because GM said so right on the oil cap.
Race Director
Joined: Apr 2007
Posts: 11,152
Likes: 890
From: South Western Ontario
its sad how many people over think cars. Has mobile 5/30 changed since 1997? Sure. Does it matter? No. Does GM still recommend the current mobile one 5/30? Absolutely. If you don’t believe me, ask your local service manager for the bulletin from GM. Always amazes me when customers think they know more than manufacturers. People will read your post and think they are damaging their engine using the current mobile one. That is misleading.
Also. post this bulletin if you're such a believer. I bet it says the old spec can be substituted by a new spec of oil, not that 1997 Mobil 1 5W30 can be replaced by 2022 Mobil 1 5W30. GM has never specified Mobil 1 specifically, it was just an oil that meet the actual spec which Mobil made a deal with GM for the factory fill because it was good marketing.
Overall, I don't care what GM now specifies as an acceptable substitute for the OEM oil requirements to use in my 25 year old car with about 175k miles on it. Not one bit. I'll keep running 0W40 because it's fine to use on the street. If I was the OP running on the track I'd go heavier, and likely Amsoil just because, talking to some racers they seem to believe in it.
Last edited by lionelhutz; Jul 7, 2022 at 12:06 AM.
Instructor
Joined: May 2022
Posts: 244
Likes: 131
From: Beautiful Texas Hill Country
Race Director
Joined: Apr 2007
Posts: 11,152
Likes: 890
From: South Western Ontario
LOL, define improved. When the engine was designed assuming a certain amount of an additive is in the oil specified for it and the new oil has less of that additive then it's not an improvement for that engine.
Last time I read info from someone who actually studied the oils, the Mobil high mileage was a closer match to the original spec.
Last time I read info from someone who actually studied the oils, the Mobil high mileage was a closer match to the original spec.
Safety Car
Joined: Oct 2004
Posts: 4,816
Likes: 132
From: Plano TX
I've had 2 C5's and a C6 ZR1... I've used Mobil 1 5w-30 and never had an issue,, you guys are making it way way to complicated, to the point its almost funny reading this thread, my old C5 Z06 is used as track car and has been beat on hard over the years with no issues, whatsoever, with over 80k miles.
Race Director
Joined: Apr 2007
Posts: 11,152
Likes: 890
From: South Western Ontario
I've had 2 C5's and a C6 ZR1... I've used Mobil 1 5w-30 and never had an issue,, you guys are making it way way to complicated, to the point its almost funny reading this thread, my old C5 Z06 is used as track car and has been beat on hard over the years with no issues, whatsoever, with over 80k miles.
Race Director
Joined: Oct 2004
Posts: 12,864
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Yup, agree 100%! Sure like to have even 5% of what Exxon-Mobil paid GM for that ad.... ..
Instructor
Joined: Jun 2022
Posts: 139
Likes: 24
From: Texas
I've had 2 C5's and a C6 ZR1... I've used Mobil 1 5w-30 and never had an issue, you guys are making it way way to complicated, to the point its almost funny reading this thread, my old C5 Z06 is used as track car and has been beat on hard over the years with no issues, whatsoever, with over 80k miles.
Means just barley good enough to make it past warranty period oil is all that is, Way better oil out there BTW.
PROOF is dealers does not have the proper oil to service these cars, IF IT was so good ALL dealers would have BARRELS of it!!!!
The Oil Wisper
Master oiler 1983-present
Race Director
Joined: Oct 2004
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