Gras 5 #1 Posted yesterday at 09:08 AM Hello sorry for the stupid question in such an expert forum, but I haven't changed the oil in my C121 for 17 years, what kind of oil should I use (0W30?)? Thanks a lot 1 Share this post Link to post Share on other sites
Achto 31,244 #2 Posted yesterday at 10:23 AM (edited) 2 hours ago, Gras said: what kind of oil should I use SAE 30wt. This is what I use in all my old Kohler engines. I know it says for diesel engines. It is a close formula to what your old Kohler requires. This may be a better option in your area. https://www.q8oils.com/fr/product/q8-garden-oil-sae-30/ Edited yesterday at 11:52 AM by Achto 6 3 Share this post Link to post Share on other sites
953 nut 64,582 #3 Posted yesterday at 12:24 PM 3 hours ago, Gras said: I haven't changed the oil in my C121 for 17 years You are one lucky guy, you should go buy a lottery ticket. 5 Share this post Link to post Share on other sites
kpinnc 17,468 #4 Posted 22 hours ago 9 hours ago, Gras said: I haven't changed the oil in my C121 for 17 years 1 1 Share this post Link to post Share on other sites
Racinbob 12,843 #5 Posted 6 hours ago (edited) All my adult life I've only used Valvoline products exclusively but the reality is that any quality product will do the job. Straight 30w in the splash Kohlers, 10w30 in the pressure lubed. Edited 6 hours ago by Racinbob 1 Share this post Link to post Share on other sites
Sparky-(Admin) 24,733 #6 Posted 5 hours ago On 3/27/2026 at 5:08 AM, Gras said: I haven't changed the oil in my C121 for 17 years Thanks a lot I have to assume someone else has been changing it the last 17 years?? 1 Share this post Link to post Share on other sites
