I noted a long time ago that I get better mileage in the TL going from a 0w or 5w-20 (can't remember) to Amsoil's straight 30. I fully expected it to feel a little sluggish but I would swear it picked up a couple hp. I didn't make a big deal about the fuel economy because it was in the 1-2mpg range which could be the margin of error. However, there's no chance whatsoever that mileage went down with the thicker oil.
You may be trading ever so slightly more friction and drag for a better ring seal. It wouldn't take much in the way of better ring seal increasing engine efficiency to trumph the minor difference in oil drag.
I know there are tons of variables other than viscosity when changing oils like FM, but I would love to see a study on HTHS and ring seal.
You may be trading ever so slightly more friction and drag for a better ring seal. It wouldn't take much in the way of better ring seal increasing engine efficiency to trumph the minor difference in oil drag.
I know there are tons of variables other than viscosity when changing oils like FM, but I would love to see a study on HTHS and ring seal.