Options for towing

[Tulecreeper]

I have a 35ft trailer that's 7000 lbs empty. My truck with 3.92 gears tows incredibly well. I have done some steep inclines (Adirondack Mountains) and it will be up on RPM and your fuel economy will suffer greatly. I'd look into trading it for another truck with a 3.92 diff. Be sure your WDH is dialed in well too.

In a nutshell, the different gear ratios only matter when getting off the line. Once you're up to speed they all work the same. I have 3:73, which isn't as good as the guy with the 4:10 to get going from a dead stop, but once we're both out on the highway we're both in 7th gear spinning the same RPM's.

++ on the WDH.

 

[azaustin]

Last summer I traded in my 2021 Diesel Gladiator Rubicon, that I ordered new, for a used (1200 mile) 2022 RAM 1500 Lariat 4x4 with the 5.7 E-torque and 3.92 gears. In August we drove it to Ouray, CO via Dolores, pulling our travel trailer that weighs around 6000lbs fully loaded and my dirt bike hanging off the back. Actual calculated fuel mileage was a little over 11mpg going and a little under that on the was back home (I think I posted this earlier.) I try to run 65mph on interstates and 50-55mph on secondary roads. At no time did I have a lack of power, including going over Lizard Head Pass (10,000 feet+). I could accelerate on any hill I wanted to. Oil temps were higher than I liked, but lower than the diesel Gladiator I traded in on it. I do like the 3.92 gears, but agree that, with the 8-speed transmission you’re probably just running a gear higher than you would with say, 3.21’s. Bear in mind too, that my truck has the 33 gallon tank, so I’m also carrying more fuel weight than the standard tank. So far I am really impressed with the truck, although I am surprised that it “porpoises“ more than the Gladiator when towing.That could be due to the adjustment on my equalizer hitch, but I am running very little pre-load. I was pretty skeptical of the E-torque when it came out, but now I’m wondering if it is the reason the truck pulls so well on hills.

 

[Tulecreeper]

Last summer I traded in my 2021 Diesel Gladiator Rubicon, that I ordered new, for a used (1200 mile) 2022 RAM 1500 Lariat 4x4 with the 5.7 E-torque and 3.92 gears. In August we drove it to Ouray, CO via Dolores, pulling our travel trailer that weighs around 6000lbs fully loaded and my dirt bike hanging off the back. Actual calculated fuel mileage was a little over 11mpg going and a little under that on the was back home (I think I posted this earlier.) I try to run 65mph on interstates and 50-55mph on secondary roads. At no time did I have a lack of power, including going over Lizard Head Pass (10,000 feet+). I could accelerate on any hill I wanted to. Oil temps were higher than I liked, but lower than the diesel Gladiator I traded in on it. I do like the 3.92 gears, but agree that, with the 8-speed transmission you’re probably just running a gear higher than you would with say, 3.21’s. Bear in mind too, that my truck has the 33 gallon tank, so I’m also carrying more fuel weight than the standard tank. So far I am really impressed with the truck, although I am surprised that it “porpoises“ more than the Gladiator when towing.That could be due to the adjustment on my equalizer hitch, but I am running very little pre-load. I was pretty skeptical of the E-torque when it came out, but now I’m wondering if it is the reason the truck pulls so well on hills.

Probably that. Porpoising is usually an affect of too much weight on the rear of the vehicle. However, it is also caused by those expansion joints in concrete roadways that set up a harmonic bounce that you can only get rid of by speeding up or slowing down.

 

[CaptOchs]

In a nutshell, the different gear ratios only matter when getting off the line. Once you're up to speed they all work the same. I have 3:73, which isn't as good as the guy with the 4:10 to get going from a dead stop, but once we're both out on the highway we're both in 7th gear spinning the same RPM's.

++ on the WDH.

What comes into play is the towing gears. There's two for the 3:21 and three for the 3:92. The 3:21's 3rd towing gear essentially became an extra overdrive gear (which doesn't really help in terms of towing.) Having the 3rd towing gear allows easier shifts without drastic changes in ratio while towing.

Given your example, we're both cruising at 65mph around the similar RPM, fuel consumption, & final ratio. We hit a hill. The 3.21 will bog down easier and start to slow down. The 3.92 has more options to select the right amount of torque to climb the hill without drastically affecting speed. Now without a trailer, if we were just driving around the 3.92 is slower/less fuel efficient at highway speeds.

Let's also put it this way. You spec out the same truck with the same options. Change just the axle from a 3:21 to a 3:92 and it significantly improves the tow capacity. The 3.92 is better for towing.

 

[azaustin]

That makes sense. However, my truck got 21mpg driving to the coast few weeks ago, and a little over 20 coming back, both times going through Barstow. That was running 70 most of the time. I was really happy. The Gladiator would have done 24-25 at best, and towing only got 2-3 mpg more than the E-torque.

 

[crash68]

I have 3:73, which isn't as good as the guy with the 4:10 to get going from a dead stop, but once we're both out on the highway we're both in 7th gear spinning the same RPM's.

Unless the tire sizes on the two trucks are different, the trucks will not be traveling the same speed in 7th gear.
At 2300 rpms in 7th gear the 3.73 truck is traveling at 72 mph, the 4.10 truck is 65 mph.
An axle ratio effects the range of each of the transmission gears, at the given rpm there is the same power out of the engine but the load presented by the speed the gearing dictates is larger with the taller axle ratio.
If both trucks were towing the exact same trailer load and did a 30 roll, you would be looking at the tail of the 4.10 truck pull away.

 

[Ramfanski]

Get used to revving high. Gassers do that when they are working hard. It’s made to do that. 2500/3500 will tow much better. It’ll just get terrible mileage comparably when you are unloaded….