I love my 22.5's but their is no way you are going to see a mileage increase unless you run cross country highway 24-7. I will say my tires didnt hurt my mileage as bad as I thought, but an hour here or there on the highway isnt going to help you out. You gotta realize these rims and tires are heavy, not to mention the added rotational mass.
I bought mine for the looks, and thats what I got. I find it hard to believe any larger rim and tire combo is going to help mileage, unless you drive the open road all the time or are in a controlled environment driving 65mph.

 

so as I suspected the 22.5s have little to no effect on the final rpms so you have to go another rout

 

No they have a big effect on final run out, but you have to get those heavy things up to speed=more burnt fuel.

 

$2.91 in Indiana where I usually fill (plus I get 4% discount for cash), and $2.95 for bio and $3.05 for dino here in IL by the house.

 

how do you figure are your tires taller than mine?

 

Haulin-RV, where do you fill in IN that you get a 4% cash discount on top of the $2.91 price?

It seems this whole issue of dropping RPM's is big money no matter how you skin it. I am leaning away from th 22.5" just because of the additional weight and rolling mass. Still in a debate what to combine with the 35" tires I already have??

 

Maybe just do both the 3.42 and the tranny gear swap and go back to 285 tires??

 

before i spent the money for a trans gear swap,plus 3.42s i'dbuy an 07 or 08 setup that way,but thats cause i just left the dealership and have new truck fever now

 

The tires that most of us are running on the 22.5 rims is 37 tall At least I am anyways (at stock height) I think your 315 is a 35.
I usually need new tires every 21-22k miles. I have 21000 on the 22.5 and their is very little wear. A new set of stock tires for a dually is roughly $1200.

 

Please explain why you guys want to lower your rpms. Are you guys running empty, and trying to save fuel?



My friend put 22.5's on his truck, and he said his milage went to poo poo.

 

Top Ten reasons to convert to the Big Wheels

Most 4x4’s are only available with high ratio gearing, and most traffic on our nation's interstate highways moves at an average cruising speed between 70 and 80 mph.

When equipped with 16" tires, the operating efficiency is out of range at those highway speeds. For instance, in a diesel truck, the ideal operating rpm range for efficiency is usually between 1800 and 2200 rpm, and most factory truck engines will turn between 2400 and 3000 rpm at those speeds. This increases engine wear and decreases fuel economy. There is a similar situation with gasoline engines.

The overall height of a typical 16” tire on a 4x4 is about 30 inches. 245/70x19.5" tires are 33” tall and 255/70x22.5" tires are 36" tall. Using the larger tires will reduce rpm by 10 to 20 percent.

Most vehicle owners are only getting a practical 25,000 miles from their tires before seeing decreased tire performance. For premium tires, that’s a $1,000 every 25,000 miles.

Most operators will get about 80,000 to 100,000 miles of wear with 19.5” tires. 22.5” tires will usually give 200,000 miles of satisfactory performance.

If you check with tire manufacturers, you will find that their tires have a four-year casing warranty. Even if you were to put 500,000 miles on these tires in four years, having had them re-capped as necessary, the warranty would still be valid.

The ride comfort using the larger tires is better than the little 16” tires because of their larger diameter and footprint.

In the average life of your truck you may buy 6 to 10 sets of tires at about $1,00000 a set. In addition, the lower rpm will reduce wear on your truck. When considering the cost of replacing your truck, these savings average about $10,00000 or more.

You save fuel because you are now operating in the ideal performance range of the vehicle. This could save you between $1,000 and $3,000. This initial investment now could save you approximately $20,000 over the life of your vehicle, provided you made the change early.

The Big Wheels and tires really look GREAT on your trucjk

 

I did not realize they were that tall

I am having a hard time buying the fact that they would ride better being the sidewalls are much shorter and stifferand why wouldnt 19.5 tires last as long as 22.5 tires?

 

i had 19.5s on a medium duty wrecker that towed as heavy as tandem axle tractors and at 150,000 miles the tires looked like new,bad thing was they had NO off-road traction at all(they would spin on wet grass like it was ice)can't remember what brand they were,i'll have to call the old tow yard next week to ask

 

Thanks for posting some sanity, Rye.

Anyone installing 22.5s on these trucks for reasons OTHER than looks needs to recalculate the pros and cons. The increase in unsprung weight is hideous. Any engineer will tell you that unsprung weight is the first weight you want to lose off a vehicle because lowering the unsprung weight has no negatives, only positives.

22.5s will wear longer. But they'll have worse traction, bruise your kidneys, destroy your steering and make life on your bearings very difficult.

Look at the bearings on an 18wheeler and compare them to your Dodge's hubs. Guess which one is designed to handle the loading of a 22.5 tire and wheel?

22.5 are almost certainly a death trap on icy roads, too.....

JMO

 

Lower rpms mean longer engine life, and you are running closer to your peak touque rating. Which = lower fuel consumption. I think in the last 6000 miles The only time I unhooked my pickup from the trailer was to enter a truck pull which I won I am usually at bout 40,000 gross when my trailer is loaded.
The Cummins pulls so much better at low rpms unlike the powerstroke and Duramax
I know my milage has not gotten anyworse driving empty, pulling it is mabey a half to one better. I am willing to bet your friend does a lot of city driving


The 22.5 have way better traction. I hauled cattle for a guy lastyear and it was a total mud hole. Two of my friends were their with their duallys and trailers. I was the only one that had no trouble backing in to load, and when loaded they couldn't move a inch and had to be pulled out with a tractor. Me, I made it half way out of the driveway.
As far as snow the 22.5 are better for one thing I now have 3 more inches of ground clearance, and with the stock tires my pickup would always bouce so bad when spinning threw snow drifts. With the 22.5's the bouncing went away. Must be to heavy to bounce
As far as bearing life I can see your point with shorter life but I will se how long they will last.
Steering components well my ball joints have already lasted longer then some.