fagnaml Report post Posted September 13, 2017 This is an "after the fact" question for the forum. In the rush the Saturday afternoon before Hurricane Harvey hit Houston, I changed the oil, oil filter and air filter on my Onan 7500 watt generator (the motorhome was to become the respite/power provider in case my home lost power which by the grace of God did not happen!). The generator was within 12 hours of needing a 150 hour service (the generator has 438 hours of total use). I purchased Cummins brand filters for the generator at PPL Motorhomes in Houston. PPL did not have Cummins-Onan brand 15w-40 oil so I purchased Shell Rotella 15w-40 at Walmart. Is it safe to presume that the Shell Rotella will perform OK when I use the generator continuously for 48 hours next weekend (September 22-24, 2017) for my LSU football tailgating outing? Thanks for your thoughts! Share this post Link to post Share on other sites
mervd Report post Posted September 13, 2017 Nothing wrong with Shell Rotella. I use it in Onan and Cat C7. Works great. Share this post Link to post Share on other sites
elkhartjim Report post Posted September 13, 2017 I also use Shell Rotella in my genset and Cummins engine. Share this post Link to post Share on other sites
wolfe10 Report post Posted September 13, 2017 Yup, you are just fine. Share this post Link to post Share on other sites
wildebill308 Report post Posted September 14, 2017 Nothing wrong with the Shell Rotella 15w-40. I think it is better than some of the other 15-40 oils out there. I have been using Shell Rotella T6 5w-40 in both the coach and generator. Bill Share this post Link to post Share on other sites
five Report post Posted September 14, 2017 Save your self some money. In the future use the Rotella in both the eng and gen....and avoid Onan brand oil. I don't mean to infer Onan makes bad oil, but $11 quart plus shipping is pretty steep. Share this post Link to post Share on other sites
