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

I switched from low pro to 11r. My rears are 3.42 and my rpm dropped by 150. Now I constantly have to downshift. Fuel mileage got worse by about 0.3-0.5mpg even though engine runs in lower rpm. Dumbest mod I did to my truck

 

What gear you can start in doesn’t really matter. The torque curve of your engine will stay the same, but your speed will change. Going to tires that are 3-4” taller overall will make your truck am entirely different beast on the hills. You may find yourself not being able to pull them as well as you used to if your engine doesn’t have the torque to spin them.

Have you priced rebuilt rearends? May be cheaper to swap in some 3.36 tears instead of buying 10 wheels, 10 tires, possibly having to buy taller 5th wheel risers, and getting your ecm tuned.

 

At 70mph I was at 1550. I mainly put 11r for the comfort after I installed three leafs springs. However, I did also think that mpg might get better due to lower rpm.

 

If you want to try it, I can trade with you

 

What is the operating range of a DD15 for best torque? What makes you feel that 1600 would be too much? Running 70+ you’ll be losing fuel economy anyway.

And yes gears would have the same end result as everything else. But you wouldn’t end up with a taller truck than the rest of the fleet. And lo 22’s are in abundance everywhere in the country because that is what fleets run. Your tall 24 choices could be limited on the road. Tires will also cost more with a larger chunk of FET since that is based on weight. And you’ll also be adding a few hundred pounds to your truck of weight is ever an issue.

Get away from a mileage contract and that extra 5 mph you’re trying to gain won’t matter as much.

 

Trucks will run 16 to 17. They do it all day long.

Mine runs 1675.

Around 1725 at full throttle in the open country.

But, running local isn't as big a deal as long haul.

 

I had a situation where I blew out a trailer tire, had 24.5's. Nowhere within 200 miles could anyone get me a tire, new, used, even a may-pop. Could sit and order one and get it two days later. Ended up having to buy two used 22.5 rims and two used tires and run a lopsided trailer axle for two days until I could stop and get another 24.5. Availability of 22.5 tires is almost universal, in many places your choice of 24.5 can be slim to non as FLD stated. Plus the added cost, and 22.5 are more fuel efficient than 24.5. The only real difference is the load rating and unless you are running overweight, 22.5 tires can handle any legal load.

If you want to lower engine rpms the most cost effective way is to slow down. Running fast does not gain the extra money that most people think, the wear and tear on all drive train components increases exponentially with speed as does fuel usage. I also know that is an argument that most will never accept - run hard, run fast, run as many hours as physically possible ... to make what others do running slow and 8 or so hours a day and taking plenty of time off.