Ultimate Three-Quarter-Ton HD Challenge: Davis Dam

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In order to bring these three-quarter-ton pickups with us for the second week of our Challenge as we drove from Davis Dam in Arizona to the Eisenhower Pass in Colorado, the answer was simple: Make the smaller trucks the cargo. It worked out perfectly. We were able to use each of them as trailer weight for our Ultimate One-Ton Heavy-Duty Challenge, which gave us the chance to bring the trucks with us without driving them the full distance.

Unlike the one-tons that were pulling 20,000-plus pounds and doing a full top-to-bottom run up the Davis Dam hill climb, and eventually the Eisenhower Pass grade, we tested our three-quarter-ton gas pickups over a specific stretch of the Davis Dam grade — a half-mile section on one of the steepest sections of the full climb. It was about four miles up from the base of the hill, where the average incline is just a touch less than 7 percent.

 

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The new Ram 2500 chassis and powertrain had a strong run up the desert mountain, clocking in at 46.35 seconds at a top speed of 79.4 mph. The 6.4-liter Hemi is impressive in this type of test, launching off the line with a slight hesitation then ramping up power smoothly and forcefully. The Ram was only a hair faster than the Ford F-250, which had 3.73:1 gears and the 6.2-liter V-8 engine. The Chevrolet Silverado 2500 (with its 4.10:1 gears) came in several seconds later with a half-mile time of 53.19 seconds and top speed of 77.7 mph.

How We Did the Testing

For weight, unlike our Week 1 tests (in Michigan, where we used bags of rock salt for acceleration and braking tests), we used 275-gallon tanks that we filled with water (bringing each tank's weight to 2,400 pounds) and strapped into each pickup bed. This put each truck close to its maximum gross vehicle weight rating; we wanted to see how capable the trucks were when with dealing with this kind of load.

Our test runs were done at night to minimize (actually eliminate) any traffic worries, and the cooler temperatures were definitely appreciated; outside temperatures during the test runs were well above 80 degrees.

Cars.com photos by Evan Sears

 

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Overview | Milan Dragway | Fuel Economy | Milford Hill Climb | Braking | Davis Dam | Eisenhower Pass | Results

Comments

Takes the Chevy a while to get going. 5 seconds slower (a lifetime) up the pass, but moving a full one mph faster at the top.

Can we get radiator temps?

How bad were Ford's headlights?
The only dual beams in the test.

We like the 6.2-liter V-8 engine; it's a strong performer and it did very well in just about all of our contests. However, we found the most problems surrounding the truck were underneath in the form of the suspension's challenged ride quality, both when loaded or empty. None of the other trucks sagged as much as the F-250, which showed a pronounced droop in the rear end when loaded. Likewise, when loaded, the ride was floaty and wobbly — especially when taking corners. Additionally, the look of the factory trailer hitch is bulky and ugly, and not nearly as integrated and well-designed as its competitors.

This one wasn't surprising. The Ram's HP advantage showed through.

But with the HP advantage, the Ram was only a hair faster than the Ford which had 3.73. The age of the Chevy showed through as it was several seconds behind.

@DJ,

But but but but but but but but.

Is that the best you have but but but but but.

Let's bust the myth that the Davis Dam grade is a steep, high altitude, or strenuous grade. It is not. The reason it is useful for testing is because it is HOT (or can be during a summer day)!

I have family in Bullhead City, and it is consistently well over 100F there, sometimes 110+. I have driven it a number of times. I even went out of my way to drive it a couple of weeks ago to refresh my memory. It is not a particularly hard pull - heck, most of it is *much* less than 6%. And it is only about 3500 ft elevation at the top.

But here this, PUTC & Cars.com, waiting for the middle of the night, or the winter, to test at Davis Dam is WORTHLESS!

If you are going to do it right then do it in the heat of Summer.

The society of Automotive Engineers (SAE) has sought for the past half-decade to bring clarity to the situation, and now automakers are getting on board, too. The SAE standard, “Performance Requirements for Determining Tow-Vehicle Gross Combination Weight Rating and Trailer Weight Rating,” is known as J2807, and a big piece of it is how a laden truck climbs a grade such as the Colorado River’s Davis Dam.

The Davis Dam grade test site is on U.S. Highway 68, just outside Bullhead City, Ariz. We started our run at the intersection of Highway 68 and McCormick Boulevard, the same place that J2807 specifies. The top of the grade is about 12 miles from the starting point. We measured 11.17 miles (59,000 feet) from start to finish, just past the Union Pass marker at the summit. The incline is a steady 5 percent for nearly its entire length.

Eisenhower Pass is 7% grade @ over 11,000 ft. Why didn't PUTC test the Ram with 90% rated load? They had the chance. Here is what they said about the Davis Dam test.

"The new Ram 2500 chassis and powertrain had a strong run up the desert mountain, clocking in at 46.35 seconds at a top speed of 79.4 mph. The 6.4-liter Hemi is impressive in this type of test, launching off the line with a slight hesitation then ramping up power smoothly and forcefully. The Ram was only a hair faster than the Ford F-250, which had 3.73:1 gears and the 6.2-liter V-8 engine. The Chevrolet Silverado 2500 (with its 4.10:1 gears) came in several seconds later with a half-mile time of 53.19 seconds and top speed of 77.7 mph."

@Hemi Vin Laden -

Ram HD - new engine and suspension.

Ford HD - 4 year old engine and really old chassis (15 years???)

Result - "Ram was only a hair faster than the Ford F-250"

Wow - that is something to brag about.

The tests were done at night when it was cooler because they did not want to take a chance that the Ford F250 would go up in flames in the heat of the day.

@Hemi Vin Laden -

Ram HD - new engine and suspension.

Ford HD - 4 year old engine and really old chassis (15 years???)

Result - "Ram was only a hair faster than the Ford F-250"

Wow - that is something to brag about.


Posted by: Lou_BC | Aug 13, 2014 1:38:21 AM


I thought "the best never rest." lol

The power of the Hemi is impressive.

Re the comment about the Chevy being at a slightly higher mph when it reached the top in a loaded condition.... When loaded our concern is how long it takes to get to the top, not how fast we are going when we get there. These are not race cars. They are loaded and most of us are safety conscious and will not be running much over the speed limit when loaded.

All ran good, should've been in heat of the day and all the way up from the bottom. Who's going to only tow 1/2 mile? And only at night? I think the ram would've just opened the gap on second place but I guess we'll never know

This is necessary to have a imvu credits if you want to play games and do chat with the 3D chat with the stranger .



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