If you go to Red-Line's website, they will have dyno testing on a C5 that proves that using their motor oil over Mobil 1 will actually give you extra horsepower. I believe they listed 8 hp gain. They said that when they switched back to Mobil 1, they lost horsepower.
I am sure Red-Line is a better lubricant over Mobil 1, but almost 95% of C5 owners would rather go with Mobil 1 because they don't want to run into any warranty issues if something happens to the engines. Red-Line says that their fluids and lubricants will NOT void new car warranties.
This week, we will be switching out the tranny fluid to Red-Line D4 ATF and the rear differential to Red-Line 75w90 on the 2001 coupe. We are sure these lubricants will offer better performance, cooling and not to mention longer service intervals.
We will probably be switching to Red-Line 5w30 synthetic motor oil on the C5's next oil change to see how much better and smoother the car will run. It is said to run much better with Red-Line 5w30.
I wouldn't worry about it. Go for it! You can only benefit from it.
I'm sure redlines motor oil is from a better base stock than M1. But its also about $9 a quart. I personally don't see the benefit of using redline for the kind of driving I do. If I spent lots of time at the track, then redline would be the oil of choice.
Redline oil will start breaking down at a much higher oil temp than Mobil 1. Will you ever reach the 450 degree oil temp Mobil 1 starts breaking down?
My car has been using Redline 5W30, Redline in transmission and rear end for last 19,000 miles with out one mechanical problem to my car
If your car is still under warrenty or wonder why a vendor who charges 200 plus percent more then the stock motor oil still has not been certified for motor oil when K-mart selling 2 buck or less oil has, then re-read the mandates again that is the service manual
Quote from page 0-39
"NOTE Oil that does not have the GM4718M specification designation can cause engine damage not covered by the warranty.
When adding to, or changing to the engine oil, use ONLY oils of the proper quality. The Corvette engine specification 4718M.
The oils meeting this GM spec may be identified as synthetic, and should also be identified with the API certified for gasoline engines STARBURST symbol.
However, NOT ALL synthetic oils with the STARBURST symbol will meet this GM spec.
Look for and use ONLY that meet GM specification 4718M" End Quote.
So to assure meeting G.M warranty rules, the oil has to have been tested by APi. have a STARBURST symbol but even then it is not G.M approved unless they tested it and gave the vendor a G-license.
To make sure you know that they repeat this at least twice in the service manual, and user manual and has a warning on top of oil filler cap.
Redline meets none of these, and quoting a vendors own test results is like clinton saying he never inhaled.
The fact is G.M states what the maximum mileage is when oil has to be changed and thus paying 2 to 3 times more for an oil going the same distance as stock out is a pure waste of money.
This vendor has had years to take their hands out of the profit stuffed pockets and get non biased tested as other approved / certified oil vendors have but clearly are afraid of something in the end test results by a neturl API testlab.
IMHO, Anyone just saying "Go do it" is not being fair to those with a warranty that could be ripped up with just so simple of a sales pitch.
As for more HP on a dyno, that's sales marketing crap, I can take the same vendors product and get the same results, using a 15W50 and a 5W30 from the same vendor and the thicker weight would cost you 7 HP.
Besides when you makeup a slick package, it may be less in friction but over time that package breaks down and causes more wear then what the stock oil would over long timeframe.
I doubt you will EVER see a Corvette owner going over 4,000 miles between oil changes and thus the costs for the snakeoil has zero merit.
John ( lost his G.M warranty for using that vendors junk)