So I wasn't sure whether to post this in the towing section or the hemi section but here goes. This past weekend I was towing my boat (approx 7k lbs) in 100 F heat. On some of the hilly stretches my oil hit 255 F and then when the road flattened it was back to 215 range. I currently am running 5w20 PUP. If i go up to 5w30 will my oil temps lower? Should I be changing my oil now after seeing those temps? I had planned to run 5k miles between oil changes. Also I only tow about 10% of all my miles, maybe even less. Suggestions?
The manual recommends 5w20 synthetic, all day every day, for all conditions. Unless your truck gave you any warning light indications that it was operating outside of it's deigned intention, like an oil temp overheat warning, I'd say you're fine. Not sure how often you're towing, but unless it's a ridiculous amount, I'd say just keep an eye on the oil life monitor, as well as check the oil itself to see when it starts to look too dark, and go from there. If you are towing a lot, and often, you can go with the Sever Duty schedule, which is to change it at every 4,000 miles, per the manual.