Change rear gears or go to 11R24.5?

i had an argument with skateboardman before on the mercer thread,this guy likes to argue just to for the hell of it,one of the old school guys who think he knows it all.

 

11R22.5 rubber is the same overall diameter as Lo Pro 24.5 there's no point in spending extra money on 24" rims unless you go with 11R24.5 rubber. Seems like a simple tire swap from Lo Pro 22.5 up to 11R22.5 would be the easiest solution.

 

Those trucks are set up for flatbed. That is not a problem except if you change to 24.5 tires your van height may be over 13'6". Need to consider the 5th wheel height as well.

My last truck was a 2007 Pete 386 with 3:36 rears, Cat C15, low pro 22.5 tires. If I ran it 70mph the fuel mileage was NOT good. At that speed you are looking at 5 to 5.5mpg at best.

The Cat assert engines do NOT do well at higher speeds. At least not the ones I have owned.

Since you are pulling a van one of their 387's would be better suited for that application. I looked at them last winter. They were lower mileage than the 379's. With the 379's you will need a roof faring or a nose cone on the trailer to help with the aerodynamics.

 

I do happen to know quite a bit more than someone with 25 years less experience. and I do think you lost the argument.

you zinita, should have a vested interest in this thread, didn't you post somewhere your truck did 65 at 1500 rpm, do you think a set of tires would cure that situation?

the needs to clarify his position as he has in the last couple of posts, to answer the question he says he really wants an answer to, here goes,

1. I don't think a change in tire size will accomplish what he wants to accomplish fully, it will lower the rpm somewhat but no get him where he really needs to be

2. a rear gear change is what is really needed to really accomplish the goal.

3. at the point of just purchasing a truck and becoming a first time operator and dealing with all that and not having disposable income (bulletproofs words not mine) it isn't the wisest thing to spend what funds are available for a tire swap or a gear change

4. becoming an owner op requires a learning curve no matter how much you've read and studied.

5. odds are buying fleet truck with 900,000 miles a new op is going to encounter some problems, and since I have looked at the rear end of the 06 acert I have for about 400,000 of its 906,000 miles, I think I am slightly qualified to speak on that subject

6. I know what the op whats to know about gearing , but I simply threw in my opinion that's since he is becoming a first time truck owner , taking some more time to find a truck with specs more to his needs would be a wise choice.

7. I am not arguing , by the way, I simply am not telling the young man what he wants to hear but what he needs to hear

8. fact is, he is no different than when I was younger, I got my head turned by things shiny and chrome, I am sure any of you with any business sense could see that as a first purchase there are many other trucks with specs that would help insure his success and profitability than a tmc fleet truck, speced for flatbed use with the aerodynamics of a brick.

9. and compared a 15 liter cat to a 15 liter cat acert engine is a foolish enterprise at best, a tiger and lion are both cats, but they are different animals.

 

bulletproof, glad you checked into it a bit more, I was going to post today and ask if you knew the engine hours on those trucks.

I think you have made a wise decision, and finding a truck that is already has specs like you wish will work out better for you in the end.

 

amen brother, I avg right 7 with mine, but that a result of careful driving , ecm work , and trying to haul light and low as much as I can.

I dearly wish a acert would get 7.2 running 74


and dang it seems the old dog has done it again,

 

My 379 has 336's with a 13spd e model cat with a Haney tune and 24lp I hit 70 at 1400 rpm
At 1500 I'm at 74 and I love it this way hope this helps good luck