jleamont Report post Posted January 2, 2018 Five, we run the Rotella T5 10w30 at work, better fuel economy. Share this post Link to post Share on other sites
five Report post Posted January 3, 2018 I'd have to run a lot more miles at slightly better MPG than I do to make up the difference in cost between synthetic vs 15w40 Rotella. Share this post Link to post Share on other sites
manholt Report post Posted January 3, 2018 FIVE. 35,000 miles between oil change ? Share this post Link to post Share on other sites
wolfe10 Report post Posted January 3, 2018 Wow! Remember oil changes per engine manufacturers specs are based on BOTH miles and TIME (annual). Also, when was the last time you heard (twitter doesn't count) of a HD diesel failure due to oil-related issue??? I absolutely use synthetic oil in my gasoline powered vehicles. But, not in my HD diesels (either Caterpillar or Cummins). Share this post Link to post Share on other sites
manholt Report post Posted January 3, 2018 Right, we are not "OTR" trucks! LOL Share this post Link to post Share on other sites
jleamont Report post Posted January 4, 2018 Yeah, the Detroit DD13 has a 35,000 mile service interval. Five, not a synthetic oil change but a lighter weight would also help. Discuss with your local Freightliner dealer, just might benefit you. Share this post Link to post Share on other sites
STORMIN36 Report post Posted February 11, 2018 Apparently you have a gas generator. However, if it's a diesel, AMSOIL has a 15W-40 that I use in my generator and it meets the requirements of Onan. It provides 4 times the protection required by Onan and is designed for extended oil changes. Share this post Link to post Share on other sites
hermanmullins Report post Posted February 12, 2018 Welcome to the Forum, Good information. Herman Share this post Link to post Share on other sites
