I am looking at getting a Dodge 3500 HO 48RE.

My current travel trailer weighs about 8,000 to 9,000lbs depending on how it is loaded. I am thinking of getting a fiver in a few years that will weigh 11,000lbs or so.

Should I get 4.10 gears or 3.73 on a dually? I want the best combination of power and gas mileage.

Brian Elfert

 

I got the 4.10 and no complaints

 

I personally would not go to 4.10s unless I was running very tall tires. At 65 mph, with a 31.5" to 32" tire, your RPMs in drive would be between 2800 and 2900. So you have to run in overdrive, which puts you at 2000 to 2100.

Typically, anything over the 2K RPM range starts to hurt gas mileage. 11K isn't that hard to pull with an HO. And you can always increase power.

For me to run 4.10s, I would have to have at least a 34.5" tire.

 

i would put 3.08s in my rig if they made them. and i haul grossed at 25k plus all the time.

 

[quote author=thecatsfan link=board=11;threadid=20410;start=0#msg191513 date=1065045066]
I personally would not go to 4.10s unless I was running very tall tires. At 65 mph, with a 31.5" to 32" tire, your RPMs in drive would be between 2800 and 2900. So you have to run in overdrive, which puts you at 2000 to 2100.
[/quote]

I never change from the stock tire size on my trucks.

I tow in overdrive. My Ford F-350 has no problems towing in overdrive.

The whole reason I want to get the Dodge with the HO Cummins is so I don't need to add power. I'm sick of having to watch an EGT gauge every time I go up a mountain grade.

Brian Elfert

 

I have the 4:10's with stock tires and it tows great, however, when I'm running empty on the highway, I would like to have the taller gears. As 11,000 pounds is not much of a load, I'd go with the 3.73's, especially with the HO powerplant.

JMHO

DeWain

 

I would never buy a diesel without 4:10's in the differentals. You buy this type truck for it's ability to pull heavey loads. So, why not pull them with ease, I know alot of people don't like 4:10's cause they think they will get bad fuel milage. Well I get about the same as everyont else, and by the way 65 mph is only about 2000 rpm, not 2900. Hell my truck wouldn't even turn 2300 stock. If you are going to be pulling a large load like you described, then do yourself a favor (and the truck) and go for the 4:10's. That way when you hit all the large hills, and everyone with there 3:54's are crawling up the hill in the slow lane, you can wave by to them as you pass.

 

With the automatic, get 4.1 gears. With the manual get 3.73 gears. The automatic has a 0.69 Over Drive ratio and the step is too large for towing with 3.54 gears like I have (I hardley ever use OD for towing - too fast to keep the rpm in a tranny protecting range). I think the 3.73 gears would also not be as good as 4.1 for the auto tranny.

 

That's really pretty much BS. That's what the other gears in the trans are for.

That way when you hit all the large hills, and everyone with there 3:54's are crawling up the hill in the slow lane, you can wave by to them as you pass.

 

The 4:10 gears are definitely the way to go if you are towing heavy. But, for 9-12K trailer weight you will see better mielage with the taller gears. I have the 3:55 gears and 36" tall tires and I can pull 15K up any interstate pass @ 80 if necessary. I also get 12.5 doing it (calculated with Garmin GPS handheld unit) smiling as I shred past the D-Max's / Stroker's. Just my opinion though LE

 

I've got the HO auto with the 3.73 ratio. Haven't been through the rockies yet, where I'm sure I won't be able to maintain my cruising speed, but going through Kentucky, Pennsyvania, NY, and the Ozarks in Missouri was not a problem while pulling my 30' high profile 5er. I easily maintained my cruising speed (65-70) by locking out OD on the steeper inclines...

 

[quote author=DPG link=board=11;threadid=20410;start=0#msg191520 date=1065046233]
I have the 4:10's with stock tires and it tows great, however, when I'm running empty on the highway, I would like to have the taller gears. As 11,000 pounds is not much of a load, I'd go with the 3.73's, especially with the HO powerplant.
[/quote]

What kind of mileage numbers do you see empty on the highway? What numbers do you see when towing? How heavy a trailer?

 

Belfort,
I have the six speed so temper my statements with that knowledge. I would have nothing but the 4.10 pulling anything about 10 - 12,000 pounds. The 4.10 puts me between 1900 and 2200 towing from 55 to 70. That is perfect rpms. Even pulling a 16000# fiver, it does extremely well in the mountains. Just got back from the Smokies in 6 - 9% grades. It did great. Mileage for the trim - - 12.7.
I get about 19 - 20 running solo on the interstate and I am still not broken in - - long way from it in fact. A 3.73 would not work for me at all at 55 to 60, I would have to drop to fifth gear.
Bob

 

[quote author=FiverBob link=board=11;threadid=20410;start=0#msg191893 date=1065114619]
Belfort,
I have the six speed so temper my statements with that knowledge. I would have nothing but the 4.10 pulling anything about 10 - 12,000 pounds. The 4.10 puts me between 1900 and 2200 towing from 55 to 70. That is perfect rpms. Even pulling a 16000# fiver, it does extremely well in the mountains. Just got back from the Smokies in 6 - 9% grades. It did great. Mileage for the trim - - 12.7.
I get about 19 - 20 running solo on the interstate and I am still not broken in - - long way from it in fact. A 3.73 would not work for me at all at 55 to 60, I would have to drop to fifth gear.
Bob
[/quote]

Yes but you also would be a optimum rpms at 70 to 75. MIne runs effectively down to about 60 then downshift for 55. I have a second gen but the gearing works out the same for this discussion.

 

[quote author=y-knot link=board=11;threadid=20410;start=0#msg191529 date=1065047647] and by the way 65 mph is only about 2000 rpm, not 2900. Hell my truck wouldn't even turn 2300 stock. [/quote]

That's in OD, not D.

With a tire exactly 31.5" in diameter, 4.10 axle ratio, tranny ratio of 1:1 (Drive), you would turn right at 2850 RPM at 65mph. It's simple math.

An OD ratio of 0.69 would put RPMs around 1970 at 65mph. That's assuming absolutely TC lockup. Would be higher with even minimal slippage.