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Buying... 3.73 Or 4.10? which gear for mPG and towing

ColoradoJason

Full Member
Joined
Apr 19, 2002
Messages
42
Location
Colorado Springs, CO
I need a bit of help determining which gear ratio is the best for me. I do not need to tow a 40ft yacht.

Here's what I know, correct me if I'm wrong:
4.10... good for towing that 40ft yacht.
3.73... better fuel economy (anyone have an idea how much difference?)

And just to define some terminology, which is the "higher" gear ratio. Isn't the 3.73 actually the higher one?

Finally, on normal roads with no load/towing, which will offer better acceleration? I don't want some soccer mom with a 7.3L diesel Excursion beating me off the line when the light turns green. ;D

Thanks, Jason
 
Unlikely that some soccer mom with a 7.3L diesel Excursion will beat you off the line when the light turns green. If she does, watch out, she may be real mad and have a gun rack.

The 3.73 setup will require 3.73 rpm for each 1 rpm of the wheels, 4.10 therefore requires mor engine rpm / wheel rpm.

In the 4.10 case, higher rpm, more torque, better towing and lower mpg. The 4.10 gets the engine into the higher torque range quicker. ;D

try search for "3.73 gear", 120 days for more info.
 
I have a 4.10. I wasn't looking at gas mileage, figured the AV already sucked gas. I do have a lead foot, and like my vehicles to move quickly off the line. I also plan on doing some towing, but it was really more to satisfy my lead foot. ;D
 
Like others indicate, the 4.10 is quicker off the line and is more responsive in the lower range. If possible, find a dealer with both on the lot and take each for a test drive one right after the other. You'll see the difference. I drove a Camaro and was used to having HP to spare. My first test drive was a little dissappointing but the 4.10s brought it closer to what I wanted. As for the MPG, I think there's proably about -0.5 actual difference with reasonable driving. (Spork, are you racing the ricers red light to red light?) ;D

 
well, I wouldn't exactly say racing.... I never go more than 5 mph over the speed limit. more like always working on my reaction time. ;D
 
I flirted w/ getting the 3.73. I wound up getting the 4.10 and am glad I did. More pep for in town driving and still works very good for high-speed highway blasts. My first road trip included spurts at 90 mph just to keep up w/ the traffic... You should see the traffic jam from OK south to Dallas as the "kids" return back to the big city after a holiday weeked w/ Mom and Dad. My 8.1L still felt un-strained even at that speed.
 
I bought a 3.73...but now wish I had gone with the 4.10..not because I have to tow anything or because I'm hauling around heavy loads....simply because I would like to have the torque "off the line" so to speak...

The 3.73 is no slouch.....I'm happy with it nonetheless...
 
I had to search for weeks to find a Victory Red 2500, fully loaded WITH the 4.10 rear end.

In test driving the 3.73 versus the 4.10, you can really feel the difference. You could be blindfolded and easily discern between the two.

Not that I particurlarly care, but I had expected the mileage to be horrible. Hey, the huge 8.1 Big Block linked to the 4.10 rear end is a real prescription for abysmal fuel consumption, right?

To my complete surprise, I get very slightly over 15mpg on the freeway and 11-12 mpg around town. Not bad for a totally unbelieveable power machine.

Glad I had the patience to search for a 4.10 and not grab the dealer's 3.73.

Steve
 
Yeah it would cost you some bucks to drop a new rear in now.....I especially feel like an idiot because the 4.10 rear was free upon ordering my Av..... :(
 
WOW!

I've never won anything in my life. I picked my AV because it was the only Z/71 with a sunroof that I could find. Not until I got home did I notice that the sticker had, "REAR AXLE - 4.10 RATIO" right at the bottom right.

I guess I finally "WON" something. ;D At first, I thought, "Oh NO!" My gas mileage will be horrific! My last vehicle was a '98 Grand Prix GTP and it was pretty good off the line. The 4:10 AVY was no slouch for a BIG truck... And, my mileage is an honest 15 hiway/city combined. That's not great but the GTP got 25.5 and used Premium. Thus the total gas cost isn't going to be TOO much more. I recommend the 4:10 because it's a no charge option. :rolleyes:

Best regards, Gary
 
If you are thinking about putting on BIGGER tires (like 33's) then you'll need to lift your Av and get the 4.10, because BIG tires and 3.73 is a bad combo. :D :D :D
 
the 4.10 may be free upon delivery, but they are certainly hard to find. When I was looking, all that was available on the lots around here were the 3.73 Most dealers i talked to were like "what is the 4.10"

I love my 4.10 and can really tell the difference... and yes I have spun the back wheels on several occasions (not much, but they have chirped), enough to cause anyone sitting next to my 7,000 lb truck to wet themselves! ;D
 
They sure favor the 3.73 rear over the 4.10......most of the dealerships here in the area also have a ton of 3.73...but try to find or inqire about a 4.10 rear and they will act like your asking them to calculate quantum physics.. ;D Maybe there is a reason why Gm rather push the 3.73's over the 4.10's?....who knows..
 
I am just thinking out loud here, so don't quote me. It seems that GM likes to offer a lot of stuff at the same price on the first model year of a vehicle, to intice people into buying.... however, because they do take a cut on these options, they don't make them easy to find... then the next model year, they offer them at premium prices..
 
The dealer closest to me has about 5 2500's with 4.10's...

NONE OF THEM have exactly what I'm looking for as far as options go. :-[
 
For towing big loads it is a no brainer to go with the 4.10. But for everyone else not having to deal with big loads you are better off with the 3.73. The taller 3.73 gears make for less engine stress at cruising speeds because the engine works less hard to maintain that speed.

For all of you "launching" off line at the stop lights you probably should have bought a sports car of some type. The AV was not designed to be a quartermile drag machine.

Now granted this is only my oppinion, and I already have a Trans AM for my "stop light fun". ;D


 
But that's where the "Gandolph" mod package comes in hand. I am guessing he eats a lot of other makes off the line... >:D

Jamie
 
Yea adding an SC will certainly make a difference, but I still think the SC would benefit more on the real heavy towing.

I can just imagine gandolph running up a hill towing a 4 horse trailer loaded to the gills at 80mph and not missing a beat.


:B:
 
I ordered my last p/u, a GMC K2500 with a 5.7L, with 4.10 gearing because I towed a trailer through mountain passes. I found that due to the steep grades, the tranny would still downshift, but with the 4.10's, the engine was turning real high revs. This time, I figured with the 5.3L, I would buy the 3.73 rear. If the tranny is going to downshift anyway, at least I wouldn't be winding out higher than needed to pull the long grades.
 
I have a Z66 with the 3.73 and it works just fine for me. Now granted I haven't towed anything and haven't had anything over 100lbs in the bed (besides myself).

Now if I was going to get a Z71 and lift it, then the 4.10's would be a must.

I do tend to have a lead foot from stop lights & stop signs... I love to hear the V8 roar and I think if I had 4.10 it would just move that much faster and entice me to do it all that much more. So I think for the sake of my gas money, I'm way better off with the 3.73. :)

David
 
It seems to me it comes down to what you want vs what you need. I tend to analyze things quite a bit before I spend my hard earned money, though sometimes I think I analyze to justify what I want to do. If for instance you won't be towing anything near the maximum, all you would need is the 3.73. But if you are planning to do some MODs to decrease those 0 - 60mph times, the 4.10 provides the most bang for the buck and is the obvious choice. Good luck with your decision process.
 
:B: I have the opertunity to factory order my AV 1500. I can choose 3.73 or 4.10 rear end. I will be towing a boat at ~3,500 lbs aprox 20% of the time.

I have read all the posts on gas milage and this is not my concern. I guess don't have a full understanding of the difference between the two, and how it affects the ride for the 80% time I am not trailering.

Any advise?
 
I am in the same boat as you. I have not yet purchased/ordered my Av, but I have driven both a 3.73 and 4.10 1500 Z71.

The pickup and acceleration was much better with the 4.10... it seemed alot more fun to drive because of that. Overall, the 4.10 delivers more low end torque and is much quicker off the line. It also had a real nice power curve. I noticed the RPMs were generally higher at the highway speeds (as it should be) which was my only negative with it, but otherwise I liked it much better.

Here is a recent post by 11H that I thought was good (you have to scroll down a bit):
http://www.chevyavalanchefanclub.com/cafcna/index.php?board=17;action=display;threadid=7651;start=16

I had originally intended to buy a 3.73, but after driving the 4.10 and reading some posts, I am leaning towards the higher ratio instead.
 
Not to upset anyone. But if it were me, I would order the 4.10 in the 1500.
 
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