I have a two year old honda snowblower. Its the big one. I only have 15 hrs after 2 seasons. Changed is last year after season 1. I only put 5 hours on it last year. Should have changed the oil a few months ago, but is it really necessary? Used a full synthetic 5w-30 (valvoline). I just checked the oil and is clear as day. I see suggestions about using a HD oil that have additives which would help with the "acidic" issues, but not sure if that is even a problem with this type of limited use.