mwr Report post Posted October 15, 2020 2015 FFH. My displayed mpg for my usual suburban driving has been in the 47s. However, lately it seems to have increased to 49-50. I remember at my last 10K service (early August) the dealer used full synthetic oil (0w15) instead of the previous synthetic blend 5w15. Might that be the difference? Quote Share this post Link to post Share on other sites
eisbaer Report post Posted October 16, 2020 Personally I would think it to be negligible but it seems that it can be a possibility at the expense of engine durability. But there may be other factors at play. I remember my Honda CT110 wold be a beast* on a colder autumn morning because of the increased density of the cooler air over a warmer summer day. *beast is also negligible terminology Quote Share this post Link to post Share on other sites
Waldo Report post Posted October 16, 2020 0W15? Do you mean 0W20? I've always used 0W20 full synthetic in mine, but I don't think the difference would be more than a few tenths of a MPG. More likely just the cooler temps and less use of the A/C. 2 MeeLee and dogo88 reacted to this Quote Share this post Link to post Share on other sites
