Gras 5 #1 Posted March 27 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 31,341 #2 Posted March 27 (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 March 27 by Achto 6 3 1 Share this post Link to post Share on other sites
953 nut 64,684 #3 Posted March 27 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 1 Share this post Link to post Share on other sites
kpinnc 17,519 #4 Posted March 27 9 hours ago, Gras said: I haven't changed the oil in my C121 for 17 years 1 2 Share this post Link to post Share on other sites
Racinbob 12,860 #5 Posted March 28 (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 March 28 by Racinbob 1 1 Share this post Link to post Share on other sites
Sparky-(Admin) 24,787 #6 Posted March 28 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
Gras 5 #7 Posted 3 hours ago On 3/28/2026 at 12:22 PM, Sparky said: I have to assume someone else has been changing it the last 17 years?? No I don't think so , but I am in France so I have a small garden (2000 m2), not comparable to what you can have in the US. I use the engine 1h a week, during 5/6 months a year. Thanks to all for your answers, highly appreciated Share this post Link to post Share on other sites
