looking to change my axle ratio

Give up everyone, we dont have the "direct experience" needed to make sense apparently.
In those three years though, he must have spent at least two of them doing nothing but "testing" direct drive transmissions.
Gut feeling? Nope, just watching other trucks pull away from me due to deeper gearing in the rear ends.
You will never understand what is not written and posted about on the internerd, and probably on KR's radio scam, oops I meant show.
I am not sure if it's an East coast Philly thing, a fleet truck thing, or what, but banging heads against walls wherever he posts seems to be a common occurrence from what I see.
What do I know though, after 23yrs in 21 different countries, his Google abilities beat my real world experience and truck ownership everytime apparently.....

Martin

 

you have driven in 21 different countries? Well if you lived in Europe, that like crossing a state boarder. you can rack up tons pretty quick.

Have you ever even driven a truck with 2.64 rears? You might pass most of them and there are 2 reasons. A guy with 2.64 rears is probably specking that way for mpg. He's prob the same guy that doesn't floor it going up a hill so he can save a little fuel. the other reason is it a fleet truck. Since most fleet truck have governors and the ball cut off, they should not be taken as a failing endorsement for 2.64/2.79. Are all drivers either slow or fleets? probably not, but most are. I didn't Google any of this. I've driven and seen 2.64's in action. You keep just saying 23 years, but i have yet to hear about any actual experience with 2.64 on a truck under 80k.

 

Back tot the OP, what speeds do you want to go. Do you do a lot of stop and go? Whats your heaviest and average load weights?

 

Neither truck is governed. I've driven both trucks, the classic being the first on I drove for this company. I cruise at 70 mph on the highway. I averaged 5.8 with that truck. I now drive the star and average 5.4. I have changed my driving habits to work with the new one. But I recently went on a trip with the driver of the other truck (the classic), both loaded to 80k. He passed me on every hill, ran the same miles as I did and did it on 5 gallons less fuel.

But I digress. The Star is still nicer and way more fun to drive!

 

What tire size? Do you know the rpm on both trucks at 70? I'll admit I dont have a solid answer to this one. The star should be around 1400 rpms at cruise which would be ideal. I'd guess there is something else in play like motor age or aero because the star seems to have a better ratio. Lol, can you dyno both of um haha. this is the trouble of specing a truck, there are so many little factors that affect this. does once have really worn tires? More of my knowledge is going from 3.55ish to 2.64ish, not the small differences near each other. what size tires?

 

idealy everyone would dyno the motor to find the perfect rpm and spec the truck to hit that when cruiseing. Your way to high on rpm, so a differnt rear should help, but in rbrtwbstr's case, it didn't help him. This is why i think there is more to it then ratios. Your 2 stories contradict and the math agrees with yours.

 

Impossible, without a direct drive and 2.64's it can't!

 

11r22.5 on both. The Star is turning 1425,@70mph. The classic is around 1600 ifbi recall.