AS SEEN IN OUR DIESEL WORLD SEPTEMBER 2026 ISSUE – Buy Now!

MIKE RYAN’S FREIGHTLINER

If you are unfamiliar with the Pikes Peak International Hill Climb, let me give you a quick introduction. Situated on Pikes Peak Mountain in Colorado Springs, Colorado, the appropriately nicknamed “Race to the Clouds” began in 1916, taking racers on a 12.42-mile rip up the original dirt roads that included 156 corners and a peak altitude of 14,115 feet, finishing at the summit of the mountain itself. It is considered one of the most brutal ascents in motorsports, with some of the steepest drop-offs and no guardrails, while featuring some of the most unique and out-of-the-box builds that almost always make their mark on this historical route.

Paving throughout the entire route started in 2002 and was finished in 2011, making a far safer, yet far faster, route up the mountain. Having taken my lowered F-150 5.0 single cab (sorry it’s not a diesel) up the mountain, it was an absolute blast. It is a must if you enjoy hugging corners and hairpins. If you have a fear of heights like I do, I promise you it was worth it. My jolly run up the mountain took me 36 minutes, which included me getting yelled at by a park ranger to slow down and getting caught behind some slow traffic just before the summit. The typical desired time for top competitors hovers between 8 and 15 minutes, depending on your class/fuel choice and how much of the track is open. If you enter your vehicle in the Exhibition Division, you are free to build whatever you want so long as it “demonstrates advancements in the practical application of motorsports technology,” and that is where almost every diesel entrant found themselves over the years.

First on our list of notable diesel competitors is one of the wildest entrants ever on the mountain: a Detroit Diesel Series 60-powered 2005 Freightliner Century Class S/T Super Truck piloted by Mike Ryan. The Series 60 had both a supercharger and a turbocharger, three intakes, water-methanol injection, and a redline of 2700 rpm, producing 2,400+ hp and 4,000+ ft-lbs of torque at sea level. What made this Freightliner so impressive at the Pikes Peak International Hill Climb was not just the fact that it was indeed rather quick for a big rig, but also how much engineering had to go into keeping a heavy, cumbersome, high-power diesel not just alive, but at the forefront in an environment that punishes vehicle size, poor heat management, and efficiency. As you increase altitude, your motor gets less and less oxygen. So, at 14,000 feet, you should expect a minimum power loss of at least 10-15% for a turbodiesel, creating more strain on the turbo to make up for that loss of oxygen, spiking EGTs, and generating way more heat overall, which reduces power and efficiency.

The turbo found on the Freightliner’s setup is an S510 BorgWarner unit, which is quite large and found itself struggling to build boost at altitude. To help with boost on the low end, Mike threw on a gigantic 8.3 L Whipple supercharger, which allowed for 25 pounds of boost even at low rpm. A ZF600 5-speed transmission, a Meritor RS-17145 rear differential, and a 3:07 rear gear ratio ensured power delivery and traction were never an issue. Fuel delivery also had to be carefully balanced. It seems simple: just give the thing more fuel to get more power. But with these altitudes already choking your motor, paired with the potential extreme EGTs, pushing your motor as hard as possible for 15 minutes straight doesn’t leave you much room to just blindly throw more fuel at it. So, they added a Banks Power Straight-Shot water-methanol injection system to use for a myriad of things: intercooler, supercharger cooling, brake cooling, and turbo cooling. Mike has said that the motor setup in this truck is more or less perfect, and he doesn’t want to change anything until after they get the perfect circumstances up the mountain.

The chassis side of the project was just as involved. Your typical big rig is designed for predictability under load, not rapid elevation changes or tight corners, meaning all stock components were thrown out to make the Freightliner predictable when throwing it into each corner. Unlike a drag truck, which is built around a few seconds of catching the weight in a straight line, the Freightliner had to survive a sustained, curvy uphill run, meaning the Howe Performance rack and pinion steering, King coilover shock absorbers, Meritor 4-piston air-over-hydraulic disc brakes, a constantly shifting ZF600, and even the Michelin XZUS/XDA-HT tires were under unbelievable stress from start to finish. Mike emphasized that the truck doesn’t have body roll at all, really; it turns easily and feels predictable even when the rear brakes give out on you during the run!

All the hard work paid off, as in 2006, Mike took the truck up the mountain in an eye-watering 12:43.66—almost exactly three times faster than I went up in something that weighs three times as much. And I can promise you I was not just cruising and enjoying the views. All we want is to see this thing make a crazy run up the mountain one more time. Be on the lookout for future entries on the diesel history of the Pikes Peak Hill Climb, as we are diving into more amazing machines that have set records and stood out among a sea of gasoline competitors.