MPG between 3.73 and 4.10 rear ends

[bamaboy473]

My 2000 Ex 7.3 (for SALE) seems to have the 4.10 rear end and the 2002 we just got has the 3.73. Here's some numbers from both trucks; each with 7.3
and 2WD.

2000 RPM:
64MPH vs. 71MPH
18.2MPG vs. 20.4MPG

70MPH
16.8 MPG vs. 19.9MPG

The 4.10 pulls a 9500# boat out of the launch at a high idle with ease, and the 3.73 takes a bit of pedal to do it although its still an easy job.

Nothing scientific about these numbers; just what I see by getting to drive both trucks. Is this about the same with your truck?

[sirnunya]

Well, mine is a bit different than yours. 8in lift, 38in tires, 4.30 gears.

70mph = 2000RPMs
mileage at 70mph = ~14 MPG

Gotten as low as 10.xx and as high as 16.xx mpg depending on fuel/driving style/conditions

[Raul@Stealth Automotive]

Originally Posted by sirnunya

Well, mine is a bit different than yours. 8in lift, 38in tires, 4.30 gears.

70mph = 2000RPMs
mileage at 70mph = ~14 MPG

Gotten as low as 10.xx and as high as 16.xx mpg depending on fuel/driving style/conditions

thats around what i see too.... its the size of our trucks... not very aerodynamic lol

[sirnunya]

definitely no Prius

[RedDye01]

Obvious results on which gear ratio offers better mpg. The thing I'm confused about is how did you go 71 mph at 2000rpm on the 02 and get 20.4mpg.........and then go 70mph (one mph less) and lose half a mpg?

[sirnunya]

For some reason I think he is going off of the overhead display...

[bamaboy473]

Originally Posted by sirnunya

For some reason I think he is going off of the overhead display...

You're right. The overhead was saying 20.4 but when I filled up, the actual was 19.9MPG.

[DCSpecial]

Out of curiousity on the 2000, what's the code on the sticker that's on the driver's side door jamb either underneath or next to "AXLE"??

Should be a two character code.

Might as well check the 02 as well and post that up.

[dbkerley]

Originally Posted by bamaboy473

2000 RPM:
64MPH vs. 71MPH
18.2MPG vs. 20.4MPG

I hadn't been paying much attention to mine until I saw his numbers. The manual may have a lower final drive than the auto. But geez, a 10mph difference.
2000 rpm = 55mph
2250 rpm = 60mph (+/ -)

on 265 - 16 tires

I had always assumed I had a 4.10 rear because that is what the build code says. Now I may have to crawl under there and mark it to be sure. (not today though - it's raining)

[bamaboy473]

I can't get the code off the 2000 (4.10?) because it's at the lot trying to get sold, but the 2002 Axle code is C1.

Does that confirm a 3.73?