This afternoon I noticed 10w-30 RT6 at my local Wally*World. They also had 5w-40 but were out of 15w-40. Would a 10w-30 synthetic HDEO be a one and done for all of my OPE in SE Pennsylvania, including the snowblower? At this point I have both 10w-30 HM and 15w-40 RT6 on hand to cover the next two years, but I am still searching for that one size fits all OPE oil.