5W40 Redline V.S. 10W30 Castrol Synthetic BLend

Not open for further replies.
May 1, 2003
I am running Redline 5W30 in my Camry and Castrol Syntec Blend 10W30 in the wifes Buick. When I leave for work in the morning it is between -2 and 4 degrees. My Camry fires up on the first revolution. THe starter turns it so fast and easy you would think it is summer. THis is with Redline Synthetic with just under 5000 miles on it. The wifes Buick on the other hand turns over very very slow and fires up with an awful racket! The oil in her car is Castrol Synthetic Blend 10W30 with about 200 miles on it! I decided to check the extra oil I have in the Castrol jug. It is in an uninsulated garage. It was still fluid but also thicker then I thought it should be. I had to shake it very very had to get it to slosh. It was almost as thick as real maple syrup in the refridgerator(sp). This is not meant as a test or as Castrol bashing either. It is meant as a demonstration of how well a well engineered comprimise oil like a synthetic 5W40 can be even when used in the winter! Depending on how the secound oci UOA comes out well be the key factor in how much I like Redline 5W40. SO far I am amazed that a 5W40 can do so well!
Not really a fair comparison though. Two different cars, and you're comparing a 10w blend to a 5w synthetic. Why wouldn't you be running the 5w30 Castrol Blend instead of the 10w30? I would not recommend a 10w oil in a Michigan winter, not even if it were fully synthetic.
JB the Redline is a way better oil than the Castrol and the Toyota is way higher overall Quality wise than a Buick imo. Group II plus III will not perform as well as a true synthetic.
Too much american car bashing here and I own a subaru! That buick could have a 3800 which could arguably be better than the camrys engine.
that reminds me of an article I read that bashed the Geo/Chevy Prism for it's fit and finish and praised the Toyota Corolla for it's fit and finish. the problem was, they were the same car built on the same line at the same time by the same people but with different badges. I've owned 2 toyotas (88 MR2, 00 Corolla) in my lifetime and a few chevies.... (various 1/2 and 3/4 ton trucks) I never found the toyotas to be any better and they were profoundly more expensive to repair. -Bret [ January 24, 2004, 10:31 PM: Message edited by: Bret Chase ]
Originally posted by Santo Fontana: Too much american car bashing here and I own a subaru! That buick could have a 3800 which could arguably be better than the camrys engine.
Those 3.8 engines are one of the most bulletproof engines ever built, there are plenty of them out there with insanely high mileage on them and still going strong. Strangely enough I believe it's the only engine left in production which calls for 10w30 as it's preferred viscosity. I'd still run a 5w or 0w in winter though (and when I had my 97 GTP with the supercharged 3.8, I did just that-running M1 5w30 in winter)
Thanks for the info John Browning! I was thinking of trying Syntec Blend. Now I will not. I run 10W-30 year around. I have used both Syntec and M1 and my Buick roars right up. Cranking at -5 F with Syntec was no problem at all. I haven't gotten to try the M1 below about 15F yet. I just swithched. Syntec impressed me with starts in the 0 to -5 range. The blend should still do better than what you describe. It wasn't "that" cold for a 10-30.
I believe that the Dodge Viper has M1 10W-30 as the factory fill. In fact my M1 bottles say this on the label. My 2000 Regal manual does endorse 5-30 or 0-30 synthetics "if the weather is very cold." They recommend 10-30 down to zero F. I'd like to try GC in fact, but not easily obtained here. I'll just stick with M1.
Not open for further replies.