View Full Version : 3.73 or 4.10 Rear Axle Ratio

05-30-2006, 11:43 AM
Noticed that the '07 Tahoe has an option for a 4.10 Rear Axle Ratio with a Heavy Duty Auxiliary Transmission Oil Cooler. Just wondering how many people would recommend this over the standard 3.73 ratio for pulling my X10? Any idea on the MPG difference?


Upper Michigan Prostar190
05-30-2006, 11:47 AM
Uh.....Russ......didn't you forget something in your poll???? :confused:

05-30-2006, 12:23 PM
I would go with the 4.10 for pulling the X-10.Mileage really should be pretty close with the 4.10 getting a little worse on the highway. You will like the extra grunt around town and with the boat though.

That being said I am going with the 3.73 in my '07 Avalanche (hopefully it comes in this week) I drive lots of highway miles (25-30k a year) and my boat doesn't weigh as much).

Evan Jones
05-30-2006, 12:55 PM
Looks like about 10% difference. At 15-18 mpg that makes it 1.5 to 1.8 mpg loss. I usually switch to the next larger diameter tire on my rigs just to improve the looks. That usually negates the effects of the lower axle ratio.

05-30-2006, 01:56 PM

05-30-2006, 01:57 PM
On a gas engine truck, IMO, it won't make any noticable difference in mileage.
I've had Dodge 1500s w/ 3.55s, 3.90s, and 4.10's. They all got bad mileage 12-13mpg empty. 7-10mpg depending what I was towing and how fast.
The latest w/ 4.10s appears to pull a little better.
W/ diesels, unless you're pulling heavy, go w/ the highest gear available, 3.73's or higher. 4.10s add too much to highway speed rpms, IMO, w/ a diesel.

05-30-2006, 02:08 PM
If I'm not mistaken, it's the higher the ratio #, the lower the gear?

05-30-2006, 03:45 PM
is it the 5.7 or 6.0 motor? As far as the read diff it wont really matter unless your pulling something close to 7500-10000lbs. Plus remember you dont pull your boat everyday so go with what works and what is good on gas mileage. I had a 2004 GMC Sierra 2500HD w/ 4:10 rear end and got about 12 miles to the gallon not pulling anything. Just my input!

05-30-2006, 03:50 PM
You are going to want to pull your X10 in third gear anyway and not in overdrive. Go with the 3.73 and your cruise rpms will be 3K at 70mph and well within the torque range of the 5.3. With 4.10s you would be running too high RPMs in 3rd and too low in OD.

3.73s with 265s, 4L60E Auto in 3rd, and the 5.3 Vortec is the perfect combination for towing.

I would only consider the 4.10s if you are planning on swaping to a larger/heavier tire.

Or you could wait for the 08 Yukon/Tahoe get the 4.10s and the 6 speed auto like the Denali/Escalade.............well worth the wait IMHO.