As my car has over 80k miles, I have been looking at thicker options. My first inclination is to just go with Redline 10W40 (97 CSt at 40C, 15.1 CSt at 100C and an HTHS of 4.4 CP) as Redline is typically a bit thicker than most and it is great oil. But I did more digging to see what else might be an option. I have always been skeptical of Amsoil but their 10W40 is actually a bit thicker (103.4 CSt at 40C, 15.7 CSt at 100C and an HTHS of 4.4 CP). I couldn't find any other options that were comparable. However, there are some 15W40 oils out there. The problem is that most of them are for Diesel engines. That doesn't mean they won't work well in a gas engine. Some do. The most commonly used is Shell Rotella but I am not a fan. Redline does have a 15W40 racing oil but it is actually thinner than the 10W40, which is odd. Of the Diesel oils, I ended up coming back to Amsoil again. Their Max Duty 15W40 looks like a good option. (112.4 CSt at 40C, 15.6 CSt at 100C and an HTHS of 4.5 CP) Their Heavy Duty 15W40 is also pretty thick. (112.7 CSt at 40C, 15.5 CSt at 100C and an HTHS of 4.7 CP) This last one should be particularly good at not shearing down to thinner viscosities over time.
Any experience with trying these 15W40 diesel oils? Anyone have a UOA on any of these oils?
Any experience with trying these 15W40 diesel oils? Anyone have a UOA on any of these oils?
