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4.10 Rear End Mileage

I

imsnowman

GUEST
We're trying to find a new 2002 (prefer the interior console).

During the search I located a Z 71 with the 4.10 rear end. We thought we wanted a 3.73 for better gas mileage.

The dealer says that GM told him that the 4.10 will actually get better mileage because the engine at "normal" speeds will be operating at a better rpm (higher than the 1800 rpm on the 3.73)

Any comments from yall?

Thanks.
 
It is unlikely that you will get "better" mileage, but you sure will enjoy it more - better off the line, etc.

The difference in mileage is small, given the truck your looking at - IMHO, I would grab it. ;D
 
I put your suggested search topics in and really didn't get much back that was germane. I just copied and pasted them into the "Search for:" section.

Did I do it wrong?
 
I have heard the same argument that the dealer gave you. I have a 2002 2500 HD Silverado with the 8100 and the 4:10 gear and the below AV with the 3:73. The gas mileage is more a product of how you drive than anything else. I have got as high as 16 mpg on the hwy in the big truck. I have not made that yet in the AV.

I would get the 4:10 if it has everything else that you want. It will use less fuel to get the Av rolling and slightly more in top gear.
 
Due to C.A.F.E. (corporate average fuel economy) ratings, I think that GM would have made the 4.10 ratio the "default" gear ratio if that were the case. Sounds more like the salesperson trying to sell what he has on the lot at the moment. It's only around a 10% change. I doubt that you would be disappointed with the 4.10's though!
 
I have the 4:10's and agree that it has more to do with driving habits and type of driving. ?With a truck like this you can not really be serious about saving 10% on fuel over having the needed towing capacity and confidence that you can handle any future towing need. ?Just my $.02 ?Go for the 4:10's
 
In the process of selecting options for my Av-to-be, I drove both gearsets back to back yesterday. The 3.73s are fine, and the truck drives very nicely. The 4.10s absolutely transform the beast. The truck has far more low end grunt, and much snappier throttle response throughout the rpm range. In my mind there's no question- 4.10s all the way. Best yet, it's a no cost option!
I agree with the others about fuel economy. The small increase in rpm at highway speeds should be insignificant. Fuel economy has more to do with the load placed on the engine and throttle modulation than it does with rpm. I think a good trick would be to leave the DIC in instant econ. mode (if you have it)- this seems to tame my lead foot when I glance down and see 4 or 5 mpg indicated. As always, YMMV. Bill
 
I am a product of the mid to late 60's muscle cars.

Get the 4.10 rear, so you can tell everybody your AV has got 4.10's.

Screw the small mileage difference, 4.10's is just very cool. :B:
 
I have the 4:10, and I love it. If you think there is a performace difference between the 3:73, and the 4:10, just wait till you try out the tow-haul(butt) button. >:D
 
I have a 4.10 and mileage is about 14 mpg in town and 18+ on highway ( not x-way). At 65 mph 2000 rpms. I would have rather had 3.73 but this one had other options I wanted. So I took it.
 
I have the 4.10 in mine and here is really all I know about it.....

On the way back from a GTG, 3 of us were traveling together on the Interstate. The other 2 have 3.73's.
We all had our cruise control set at about 75mph and were runinng about 2100rpm. The only difference was going up a hill. The 3.73's would kick out of OD and their rpm increased while mine stayed in OD.
By the way..I average 17.5 highway.
 
I had a 2001 4x4 silverado with the 3.73. It got close to 17mpg. My 03 Avalanche has the 4.10 and gets about 15mpg. The lower gas mileage is definitely worth trading for the extra get up and go the 4.10 gives.
 
GMFC1 said:
I had a 2001 4x4 silverado with the 3.73. ?It got close to 17mpg. ?My 03 Avalanche has the 4.10 and gets about 15mpg. ?The lower gas mileage is definitely worth trading for the extra get up and go the 4.10 gives.
Click to expand...

Your not mentioning that the Silverado was probably about 1000 lbs. lighter than your Av. That in itself could account for a lot of the mileage difference between the two vehicles.
 
I had the 3.73s in my '00 Tahoe 5.3 4X4. Grabbed the 4.10s this time in my Z71 Av. BIG difference in off-the-line acceleration. Not too much difference in mileage, if you can keep you foot off the gas.

But be warned!
Those 4.10's + V8 + way too much fun! ;)

Mike
 
I don't see any real difference in the gas mileage. I agree with an earlier post, that your mileage has more to do with how you drive. I have the 4.10 and find that I am much more willing to jump off the line for the fun of it! (Bad for gas mileage.) On several long trips at ~60 mph the AV tops out on the MPG curve at a average of 18.5mpg. It has been as high as 20mpg. At 80 mph average speed, the mpg has dropped to 16.5 mpg. In town, the AV is gettting more like ~14 mpg.

Fun v. Economy If you are looking for economy, you have the wrong truck (5600 lbs). Fun wins! IMO
 
If you want the max mileage then get the 3.73's.

If your looking for stop light to stop light performance, putting taller tires on or towing a heavy trailer then go for the 4.10's.

I can't believe that the salesman would think anyone would fall for that GM says the lower gear will get better......If you put 20 gallons of gas in two AV's one with 3.73's and one with 4.10's, drove down the highway in overdrive, which one would be on empty first.
If this were true then all I would have to do to get better mileage is take it out of overdrive and my mpg's would go up......R


 
But does anyone here have a 5.3L 2wd (Z66 or no) Av with 4.10's? I'm still undecided... I'm a big accelleration fan, but I do drive ~30 miles each way to work, mostly highway... ???
 
A little perspect here, I think. If you are buying a big ass truck and worrying about minor mileage difference, maybe you are focusing on the wrong things. Yes, in theory, there would be a drop in mileage. But, I would imagine over the life of your truck, we are talking about insignifican dollars.

I kept a close eye on my mileage this summer while traveling in Atlantic Canada, towing a 4000# trailer, 4 bikes on the roof and a fully loaded AV. At times, we got down to a dismal 9mph. But then, we are talking about fully loaded here. No idea what the mileage might be unladen.

Buy the AV and have lots of fun with it.

Chris.
 
we have a 1500 ( no Z's) 5.3L & 3.73. just got back from a 2800 mile vacation. got 20.2 mpg and did not use any oil. we were not pulling a trailer but the AV was loaded.

 
FutureAv said:
In the process of selecting options for my Av-to-be, I drove both gearsets back to back yesterday. The 3.73s are fine, and the truck drives very nicely. The 4.10s absolutely transform the beast. The truck has far more low end grunt, and much snappier throttle response throughout the rpm range. In my mind there's no question- 4.10s all the way. Best yet, it's a no cost option! ?
Click to expand...

:eek:

I don't think I could live with a 3.73 Av! I've got 4.10's, and think of it as 'allright' as it is. :)

It IS pretty cool how you're in 3rd gear by the time you cross intersections though. (y)

I think the only area where the 4.10's MAY hurt the mileage would be on the highway.

Around town, it'll just bump up into 4th / OD at a lower speed than it would if you had 3.73's.

On the highway, I sit around 2100-2200 around 65/70. I'm sure you'll be lower than 2K on the tack with 3.73's.

The "MAY" part - the 4.10's will be able to lug up hills easier without downshifting. The 3.73's will have to kick down a gear for some hills, hurting mileage.

If you're somewhere flat, like FL or out in the desert, this may be a moot point. In my hilly New England travels, I LOVE the 4.10's though.

Best mileage to date was 18.6.
 
For what it is woth....I have the 4.10 in my '03 and just did a 3500 mile round trip and the DIC recorded an average of 15.3 mpg. Keep in mind thats with 3 passengers and about 500-600 lbs of luggage & gear. I averaged 50mph over the entire 3500 miles.
 
I ran ~500 miles of mixed highway (60 mph) and freeway (75 mph) around Jan 1. I averaged around 18.4 mpg with my 5.3/4.10's according to my trip computer. I love the acceleration of the 4.10s! :)

Mike
 
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