Safe RPM's Traveling up a 7-10% Grade

[silver billet]

Hi All,
New to the forum, but been reading for 6 months. Hoping this is in the correct area and not towing??

Question/Problem: A sales manager at a Travel Trailer place said I "should be towing" over 5000 RPM's, so I can go faster up a mountain AND buy this new trailer that weighs an additional 1500 pounds. This is not a "Can I or should I tow" because all the numbers say I technically can with a 23% cushion in the numbers. My question is about the RPM's and how high you can actually travel for 10-20 minutes at a time while climbing. Is 4200 the max or should it be 5000 RPMS?

Truck- I have a 2021 1500 Limited. 3.92 and the towing package.

Background- I have been towing my fully loaded 4900# travel trailer for 9 years total and 3 of those years with my 1500. Very easy to tow, however going up 7% grades at elevation of 4000-7200ft, I keep my RPMS are at 4000-4200 and I am at 52-54 miles per hour and I don't rev higher because of the sound.

Prior to 3 years ago, I had never owned a truck. I am open to all comments because I know the manager does not care about me or my truck. thank you in advance.

You should not be at 5000 rpms for 10 to 20 minutes. Not in the 5.7. The 6.4 in the 2500 is able to deliver its rating for up to 12 minutes WOT IIRC, but the 5.7 is not. The guys over at TFL will wind up these engines for up to 8 minutes in their torture tests but that's exactly what it is, a torture test. I'd never put my truck through that even if it could do it, just slow down a bit.

I'd back off, let the truck do its thing at a slower speed and RPMs, its not a race. In my area the most I see on flat ground getting up to speed from a stop is 3500, going up grades I'll hit that again or sometimes just over 4000-ish but that's where I sit, max, for under a minute just due to the size of the grades as I don't have any larger ones. Cruising on the flat freeway at 63 mph it will do 2200 rpms all day long with no issue.

And most importantly, oil choice is critical for loads like yours. Get a good 5w-30 or even a Xw-40 for the summer months when towing. You need that HTHS to mitigate wear under that kind of work load. Redline 5w-30 is a very popular and great choice. Also change it at 5000 miles and not when the indicator tells you to which is way too long.