IMPRESSIVE!!! Thanks for telling me that! I had already thought to
go for the 3.73 gears (and 33" tires), but now that you have confirmed it,
I feel even more confident about it. I also think that even from a fuel
economy standpoint, the 3.73 ratio coupled with the 33" tires still makes
sense... Given I won't be towing, I think it will save me fuel compared to the
4.10, except perhaps when driving up the toughest mountain roads...

Regarding the 6speed... one of the things I hate about automatics is
when you drive down very steep roads and the automatic tranny doesn't
provide enough slow-down resistance and you end up using your brakes
constantly... I used to drive a 1-ton Econoline cargo van (auto tranny),
and even when using the special slow-down gear provided for such
situations, my foot was constantly on the brake pedal when driving
down mountain roads... Totally different story with a manual tranny...
And it gives you much better overall control over the driving experience.

 

Well, you can always sell it on ebay or keep it if you think you will use it later. For example a full set of stock wheels and tires go for anywhere between 800-1100 on ebay. If I sold mine on ebay for 800 thenit wouldbe like I hadonly spent 600 to get my new ones. Some things are good to keep though. Like I had my muffler and cat replaced with a straight piece of 4" tubing, I kept the muffler and the cat just incase the new emmissions stuff starts to affect my model year truck.

 

Great! Thanks for sharing...

 

Peak efficiency is 1490 and peak torque is 1550 at least for my year. So by having the trucks geared to turn higher RPM at highway speeds they are after a thing called torque rise. It's a trucker term, basically if you slow down the engine makes more power rather than falling out of the usable power range of the engine and having to grab a gear right away. So that is one of the reasons driving a little slower you get better fuel mileage, the other major reason being all the frictional losses.

 

I don't mean to get too technical and become a nuisance here, but...
I think it likely that there will be some forum members with peak
efficiency and peak torque data for both the 2007 5.9L and 6.7L
and a mathematical knack for playing around with technical data...

So, is it possible, with a few computations, while assuming these
engines in 2007 2500 SLT trucks with 4x4, 6-speed manuals
and 35" pro comp X AT tires on stock alluminum wheels, to
discern which vehicle becomes more fuel efficient - and more or
less how much so when compared to the other - when we consider
two non-towing vehicles traveling at 60 mph on a flat surface
(presumably in 6th gear) for a distance of 100 miles, one equipped
with the 3.73 gear ratio and the other with the 4.10, and this for
both instances of the CDT 5.9L and 6.7L?

I know, I know... I am probably becoming a pain asking this sort of
question, so, if it is totally off the wall, forget about it... [sm=guilty.gif]


How about a few guesses, based upon practical personal experience
and aside from sweating out the math problem? [sm=grinangel.gif]

 

all you need is one of these and your done



http://www.genosgarage.com/prodinfo....BP-55077758-AA

 

Thanks, but no thanks... With a couple of dollars more than that costs,
I think I can get a Carli 3" lift (some say it lifts it up as much as the
BDS 5"...), so as to be able to comfortably run 35's... [sm=happybounce.gif]

 

a stock 4x4 can run 35's with maybe a little rub. a leveling kit can run 37's

 

It will be a 4x4, all right... but who needs the rub, right?
I find the Carli 3" interesting, just a bit taller than a 2", even
though these kits you find around don't all lift exactly as much
as they say they do (the Carli seems to lift a bit more than
that...)

The vehicle, with 35's on, looks much better when it is a little
bit taller...