Which one is better?
So far, so good on the Red Line. Good reviews from what I have read too. We get cold weather too but our winter was so extremely mild I didn't get a chance to test it in anything really cold. We also get really hot weather, and I've already driven in 100F weather. No issues there. I thought the formulation (ester and PAO I'm assuming) will help with the heat and decrease oxidation. I'm also maybe at about 70% new fluid given my two drain and fills (first with the filters, second without). Going to do another drain and fill in about 5000 miles and then do it every 10k I think after that. Not sure I'm doing the cartridge filter ever again. Getting that top rear bolt on and off was a nightmare in that cramped space. The filter inside the transmission looked pretty good after ~70,000 miles so maybe if we still have in 70,000 miles I'll do it again haha.