I am going to order a new Dodge 3500. I tow heavy loads about 30-40% of the time and run empty the rest of the time. I have always had 3.73 gears in the past which did a pretty good job towing; however, I believe 4.10 gears would be better. My question are:
1. is the 4.10 really that much better for towing 10,000 to 14,000 pound loads, and
2. what is the difference in fuel mileage between the two gear ratios when a) towing and b) when empty.
Your comments would be very much appreciated.

 

1. Yes, for towing the 4.10 does provide a noticeable difference in towing performance

2. If your towing at 60mph or less, the 4.10 is the way to go. But if 60-70% of your time is unloaded at hwy speeds (70 or more) you will feel the pain. IMO, the most important factor in FE is engine speed vs. road speed. You have to get the engine speed below 2000 to get good fuel economy.

 

Presently, I am planning to go with the auto trans. However, deciding on auto vs 6-speed manual has been another tough decision. Given that the majority of my driving is done with no load, I thought it might be best to get the auto. However, I believe the manual would be preferable with a load.

 

I don't know what would be better for you but I really like the 4.10's.

I didn't order the truck like that but the previous owner did because of future lift plans. He passed away shortly after buying the truck and I picked it up with 4,000 on it. I tow my race car but it isn't alot of weight and I only tow 3or4 times a month. I may still lift the truck or atleast put 315's on it so the gear will still come in handy.

As far as mileage, I just made my first long road trip, about 550 miles each way and I drove between 60-75 the whole way and a good portion was through the mountains of VA,MD and PA.

I averaged 19.2 mpg hand calculated.

 

To me, the way this truck pulls it would be a waste to have 4.10s unless you're constantly pulling at low speeds as mentioned above. I have the 3.73s and drag 10-12000 around all the time up and down hills at 65-75 mph and thats with the 295s on! With fuel prices the way they are, get the higher gears because the Cummins will still pull that amount of weight no sweat. I don't want to be running 2200 rpms at 70 mph all the time when I would have the power to do it at 1900... It's funny but sometimes I think guys are almost as protective of their differential ratios as they get about certain kinds of oils...Their seems to be almost a fierce defense of the 4.10 ratio on these sites, but I think some of this goes back to the days when we didnt have near as much power and torque at our disposal as we do now. My old 7.3 NA wouldnt have been able to accelerate ITSELF without 4.10s! This 600 with 3.73s will way outpull the old school CTDs stock with their 4.10s by a country mile, and boy didn't everyone think they were great when they were the powerhouse on the block! This is just my honest opinion from my experience. Nothing wrong with either one of them, just need to find which is best for your application. For mine, 25% towing 10-12K, rest highway and running around town, the 3.73s are my choice.

 

My last diesel was a Powerstroke and it had the 4.10ls - my 2005 Ram CTD I got with the 3.73. The reason is when I tow - I run 70-75mph and the rpm's are too high with the 4.10. And when I was empty I hated running the truck at 2500RPM, besides the diesel makes most of its power at 1600-1900RPM. If I towed at lower speeds, say 55-65mph max I would go for the 4.10.

 

I have found the truck pulls best over 2000 RPMs, the 4.10s work pretty well if you want to run 70MPH, 2150RPMs, when I run below 2000 RPMs I have to downshift to 3rd to pull hills. I am towing about 9K lbs with a large frontal area. I usually don't drive over 75 mph empty but the other night I was in rush, the trucks runs super smooth at 2500 RPMs, fuel mileage did not seem to suffer much either.

 

In reality, either set of gears will be ok - the Cummins can handle it.

But as I see it, for the 40% of time you'll be towing, the 4.10's will come in very handy - and you'll really appreciate them. For the rest of the time, those same 4.10's won't suffer anything in terms of fuel savings.

FWIW, the auto has a slightly higher OD over the 6 shooter.

 

I agree that this really is something that is up to the person. Both would be fine. I often wonder how much better my mileage would be with the 3.73's but getting over 19mpg with 7,000 on the clock makes me happy regardless. If I was ordering the truck, I am not sure which route I would go but I really don't think the 4.10's hurt me at all.

I just know that leaving stoplights with the race car behind me is a blast now. I used to have the Hemi's pedal darn near to the floor to get her going.

 

I chose the 3.73 because I tow only about 4x per year. I have towed twice now (about 10k) and don't regret my decision. Any place it gets "iffy", I just push the tow/haul button. No big deal.

If I hauled bigger loads way more often, I might have chosen otherwise.

Just my $.02

 

I have the 3.73 in mine w/6spd...longest haul was from Vegas to Ft. Rucker, AL....hauled a 20' enclosed carhauler loaded with all my mothers earthly posessions...weighed in at 13,000 approx.. got 9.5 mpg at 80mph the whole way when I was driving and when on a flat and level, could start in 2nd....let my mother drive it part of the way while I tried to rest and going east up into Albequerque, NM never had to downshift outa 6th...I know mpg sucked but thats due to the 80mph...cant complain about the gears..

 

Towing at 80!

 

Ya, 80 is a bit high....I was doin training in AL and was called and told that I was being deployed....I had to make it home to Vegas in 2 days, pack and get to CA in another day....So, 80 was the only way to make 2000+ miles in 2 days...made it from the S/E corner of AL to Amarillo TX the 1st day then the rest of the way into Vegas the next...I know I shouldnt tow that much weight over 70mph...