2003 Western Diesel PickupTruck.com Diesel Shootout, Part 2 of 3
By: Tom Keefe © PickupTruck.com, 2002
Posted: 11-25-02 00:00

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Part 1: Quarter Mile Drag
Part 3: 15% Grade Test

The flat ground of Milan Raceway allowed us to determine which diesel pickup was the fastest over a set 1/4-mile distance, loaded and unloaded. But while flat ground testing can establish best-in-class acceleration, the true measure of diesel performance is how well a pickup can climb a hill, with and without a load.

This test was a climb up a 7% grade. It was limited to one direction, uphill. Each driver made three runs empty and three runs loaded in each of the vehicles listed below:

2002 Chevrolet 3500 Heavy Duty
Extended Cab 4x4 dual rear wheel, Duramax diesel 6600 6.6-liter, 6-speed manual transmission, 3.73 rear axle ratio and a curb weight of 6970 pounds

2003 GMC 2500 Heavy Duty
Crew Cab 4x4 single rear wheel, Duramax diesel 6600 6.6-liter, Allison 5-speed automatic, 3.73 axle ratio, and a curb weight of 6950 pounds

2003 Dodge Ram 3500 Heavy Duty
Quad Cab 4x4 dual rear wheel, Cummins High Output 5.9-liter diesel, 6-speed manual transmission, 4.10 axle ratio, and a curb weight of 7927 pounds

2003 Ford F-250 Super Duty
Crew Cab 4x4, single rear wheel, Power Stroke Diesel 6.0-liter, 6-speed manual transmission, 3.73 rear axle ratio and a curb weight of 7188 pounds

2003 Ford F-350 Super Duty
Crew Cab 4x4, single rear wheel, Power Stroke Diesel 6.0-liter, TorqShift 5-speed automatic, 3.73 rear axle ratio and a curb weight of 7250 pounds

Over 10 runs up the hill for each truck in each configuration, the best and worst runs for each driver were thrown out and the remaining times then averaged.

The speed measurement was calculated from the recorded time divided by the distance. For example: (430-ft./5280-ft.)/(7.44 seconds /3600 seconds)=39.41 MPH, this would provide the miles per hour over a 430-foot long course where 5280-ft equals the distance in a mile and 3600 seconds equals the number of seconds in an hour.

Many of you will notice that we moved the Chevrolet to the trailer and ran the GMC, which was slightly different from the Milan Test. Both vehicles weighed the same and had the same engine, tire, and axle ratio so switching did not seem to be a big deal.

For this test we used a 1,720-foot long hill (just shy of 1/3 of a mile) with a seven percent steady grade. We set electronic eyes on tripods every 430 feet and readers connected to automatic stopwatches in the cab of each truck. The readers were triggered as the vehicle passed the electronic eyes. This equipment was different from the equipment used at Milan Raceway. Each vehicle was timed in seconds from start to finish every 430 feet, except when the vehicles were empty.

We did work around one snafu. Once the testing began, we found our testing equipment would not read if less than 5 seconds of time had elapsed between electronic eyes, so we adapted our test for empty loads to only three measure points because the time from 860 feet to 1290 feet was always less than 5 seconds when running empty. In fact, as you look at the data, we nearly didn't get a reading at the 860-foot marker because all of the trucks posted nearly identical times from 430 feet to 860 feet.

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