Anyone have firsthand experience going from 22.5's to tall rubber tires?

Correction. 15 and 16.

 

That’s all us locals run 11R24.5 16 ply......

 

“But if you ran 255/22.5 you could save fuel money!!”
Specially bc you couldn’t load to your permitted weight lol

 

Those of us with a few more years experience could tell you when you would NEVER run an engine at 1500 that would be abuse ... normal range used to be 1600-21oo rpm and when guys would "shim" their fuel pumps they'd be running 2400 rpm. Times have changed.

 

Electronic fuel delivery, is what keeps them together at low rpms, on the old manuals you could lug them down and still be pouring the fuel to them, for a short distance. Lots of different technology on air too.

I read one time that the b model cat engines were actually tested at 4,000 rpm, I wouldn't want to do it, and don't know how true it is.
I will say my e model cat will still turn 2100, and it is not at all unusual for me to go up to 2000 to gain some momentum on some steep grades.

 

Certain breathed on engines with timing advanced and fuel tables adjusted need rpms to keep the engine alive...

Putt around town all day long at low rpm fine . But put a load on it and on a hill with lots of boost you need rpm .

 

Times have changed.

Remember when tach was color coded and redline.

 

47.5 inch 5th wheel height to be 13'6 on most vans. And even with todays new engines 1600-1650 is optimum for pulling any type of hill