When I bought my Durango 4 years ago, it was a no brainer. I got the higher ratio 3.92 rear end. I really didn't care about 1-2 mpg difference, but I REALLY cared about towing capability.

I'm doing my initial research on a 2500 QC 4x4 w/CTD, and I see that the Dodge site doesn't show a difference in tow capacity between the 2 rear end ratio options. There was a significant difference in the Durango's towing ability between the two available ratios--no problem.

So, I have to ask myself, what are the criteria for making a decision in this case. I still really don't care that much about 1-2 mpg difference in fuel economy, so what do I look at? Is there better acceleration with the 4.10? Is it easier on the tranny? Is the 3.73 a better choice for XX reason? What should I consider?

Thanks,
David

 

Discussion on this before have come to the conclusions (sort of) that if you are going to put big tires (315) on it then do the 4:10 thing. Other than that it is a matter of choice. I'd rather have a 3.55 or even lower or another gear for the top end. With the 6 spd you have good rpm because of the gears to choose. Dunno about the auto tho.

 

I've got the 3:73s in mine and pull a heavy (10,000#) trailer. I pull through some pretty mountanous terain as well. With the 6 speed I have zero problems with those gears. The 6 speed also allows me to have an exhaust brake which I consider mandatory on mountain roads.

If you are considering an automatic, perhaps someone else can weigh in.

100 Proof

 

If you're going with the 6 speed then definitely get 3.73s. I have 35s with 3.73s, and it's still geared too low (37s?). I can't imagine stock tires with 4.10s... you'd be in 5th gear at 30 mph! For the auto with big tires I'd go 4.10s though.

John

 

The last time I looked at the towing guide on the Dodge Web site there was a difference shown in the GCWR for the 3500.

3.73 = 21,000
4.10 = 23,000

jr

 

That's true for the 3500's but for the 2500's the Dodge site shows no difference.

 

Since you're debating, you must be panning on ordering. So, you'll be getting a 600. It should pull just fine with the 3.73s. My puny little HO does fine with them. I also debated between the two. Chose the 3.73s as I do a lot more driving NOT towing than I do towing.

 

In my book, if you're pulling 10000lbs or more go for the 4.10s. I had a 99 2500 SO CTD auto with 3.55 and the trailer was a tough pull with it. I moved to an 01 2500 HO 6sp with 4.10 and it was great. RPM at 60 was just over 2000 and the extra power and 4.10s were really nice. This truck got about 2mpg better than my 99! Now I have an 03 3500 HO with 48re and 4.10s. Mileage runs around 17 empty and about 14-15 with the trailer but it's not a fair comparison to my 2500s. I still like the extra pull with the 4.10s and would order again.

I don't pull a lot in the mountains but did an east coast trip in June. Was on a couple of 10% grades and didn't find the truck pushed much going down the hills. Grades were not more than about 1/2 to 1 mile though. As a result I haven't felt the need for the ebrake. That's good because DC hasn't approved it.

I think it really boils down to preference. I know guys with the 3.73s and they like them!

Good luck....

 

If you're an occasional tower - heavy or not, and mostly a daily driver kind of vehicle, I'd recommend the 3.73's.

I've got the 4.10's and love them when I'm pulling the boat, but otherwise I find myself looking for 7th on the highway.

Mileage differences won't amount to much.

 

Wow. Thanks for all the great responses. It really does seem to be a toss-up since the ratio doesn't affect the tow rating.

Thanks!
David

 

3.73s

You're in the same situation as me. Occassionally towing around 5K to 8K and that's about it. Daily driver while looking good.

 

My truck has 3.73 gears in the rear.
It is my daily driver. The most I can find to tow is about 8000lbs of fishing boat. NO PROBLEM.......
Some times I wish I had something like a 3.55 IMO
If you Tow heavy then Go low If not the save the rpms and the fuel.
Either way you will be driving the best diesel on the road.
Happy Holidays

Diesel Fool

 

I believe with stock tires 3.73 1900 rpm vs 4.10 2200 rpm around 70 mph probably 1-2 mpg better with 3.73's

 

There isn't much difference in 3.73 and 4.10, either will suit you. At 65 mph in overdrive, there is only 190 RPM difference between 3.73 and 4.10. I've grossed around 38,000# and I have 3.73s, pulls strong. If I was gonna be heavy loaded in hilly country alot, I'd go with 4.10.

 

Hey David,
IMO the tire size you want to be using plays a big roll in that decision. Also consider how heavy you want to tow and the speeds you like cruising at unloaded.

I have 3.73's with 33" tall tire and an auto trans. The auto trans overdrive with converter locked provides a taller gear than a manual trans. I pull 6000 in the mountains just fine and on freeways unloaded I keep it @70 or below cuz the fuel mileage drops way off from there.
If I wanted 35" tires then 4.10 would be a better selection for towing using an auto trans.

Now if you like to keep the stock size tire, drive at 80+ with a manual trans then 4.10's would not be a good selection unless you tow real heavy all the time. You will be winding the snot out of that motor