It’s finally time to put the newly refreshed 2025 Ram HD pickup truck lineup to the real world test. We take this new Ram 3500 Laramie Sport crew cab dually 4×4 up and down the very important Davis Dam highway with a 19,000 lbs in tow. How does the new high-output Cummins turbo-diesel behave? Is the new 8-speed ZF Powerline automatic transmission worth the wait? Let’s dig in!
The big story is two fold. First is the 6.7L Cummins turbo-diesel straight-six engine that has been revised to produce more power and offer better serviceability. Next is the introduction of a brand-new automatic transmission. Starting with these 2025 model, all Ram HD 2500 and Ram HD 3500 pickup trucks will offer the same high-output engine and the same Powerline transmission in all models.
This version of the engine is rated at 430 hp @ 2,800 rpm and 1,075 lb-ft of torque @ 1,800 rpm. The new automatic transmission has a low 4.71-to-1 first gear ratio. The sixth gear is 1-to-1. Under many light-load circumstances (when the truck is not in Tow/Haul mode), the transmission will start out in 2nd gear. If more torque is needed (tow/haul mode or a heavy loaded condition), then the transmission will pull away using the 1st gear.
Here is this truck’s window sticker, so you can see all of the optional equipment and the MSRP.
Ram invited us to this first-drive opportunity out of Laughlin, Nevada. They prepared the trailers and hooked them up to the trucks. We have an opportunity to drive the famous Davis Dam grade. This route is used to set the maximum tow ratings for all pickup trucks (and large SUVs) as a part of the SAE J2807 standard.
We are pulling a gooseneck equipment trailer that has a GVWR of 23,900 lbs. Ram tells us that the total weight of this trailer is 19,000 lbs.
It’s smart to not load a trailer close to its capacity. Take a look at this trailer’s payload sticker. It uses two 10,000 lbs axles, so it assumes that you will put at least 3,900 lbs of tongue load onto the gooseneck hitch ball. The Ram Truck team loaded this trailer to a total weight of around 19,000 lbs, so it’s safely within all limits.
This 2025 Ram HD 3500 Laramie Sport crew cab 4×4 dually has a very high level of capability. This particular configuration of the truck (with all of its optional features) has a maximum payload rating of around 5,400 lbs and a maximum gooseneck towing limit of 33,500 lbs. This 19,000 pound trailer should be child’s play for it.
Although, the Davis Dam grade is not easy. It’s an 11.5 mile climb from the Davis Dam and the Colorado river up to the crest of Union Pass. The incline varies between 5% and 6% grade. The highway gains around 3,000 feet of elevation over its distance. The top of Union Pass is close to 3,500 feet above sea level.
We still claim that the Ike GauntletTM is still the world’s toughest towing test because the top of this Eisenhower Tunnel grade is at 11,158 feet above sea level. It is an 8-mile stretch of the I-70 Interstate with a 7% grade.
The toughness of the Davis Dam test comes into play during the summer months. The SAE J2807 standard requires manufacturers to run up this 11.5 mile route with the ambient temperature of at least 100 F, with the truck’s AC system set on maximum cooling and maximum fan speed.
I am happy to report that the new Cummins/ZF transmission pairing is great. The transmission shifts quickly and smoothly. It keeps the engine in its optimal power curve, and I had no trouble keeping a steady 65 MPH all the way up the Davis Dam grade. I set the adaptive cruise control system, and the let the truck manage the rest.
The Ram’s suspension was nowhere near maxed out. The ride was comfortable and stable. This is precisely what you want from a great towing truck.
The way down the mountain was also uneventful. The new Ram HD diesels still have a 2-mode exhaust brake. There is the full-on and the automatic mode. I used the automatic mode on the way down to maintain the 50 MPH speed limit that is set for heavy trucks (passenger vehicles still have a 65 MPH speed limit).
We monitor the full compliment of gauges on the way up and down. Ram has some of the best digital gauge displays in the business. They added a feature where you can monitor a graph of the previous two minutes for turbo boost pressure, coolant temp, and several other parameters.
This truck get a high passing grade for this test. We hope to get a Ram dually Cummins to our home in Colorado. We plan to load closer to the 33,500 lbs trailer tow limit and run the world’s toughest towing test.
In the meantime, please join the latest real-world test video at the TFLtruck Youtube video channel.
