Posted on 27 June 2015
Cummins, Duramax and Powerstroke engines are the backbone of towing applications. For work or play, these motors provide substantial torque and economy gains versus any gas motor in a pickup.
How do you make your diesel engine perform better? Can these upgrades pay for themselves? How much is too much when it comes to modifying a diesel built for towing?
Diesel engines operate on a simple principle. Air + fuel = power. The slightest increases or improvements in these two areas can mean huge gains for economy, torque and lower EGT's. At Street Diesel Power, we talk to a lot of customers who do hot shot work for a living. Some racking up 3000-4000 miles every 1-2 weeks. If that truck could get 1, 2 or 3 mpg better - that is money in the driver's pocket. Products like tuners, intakes, exhausts and injectors can help diesel engines get better fuel economy.
Time. Getting from Point A to Point B in a safe, but faster manner, saves operating costs. Pulling a grade in the Rocky Mountains, and having to back off the throttle due to high EGT's, kills efficiency and time. We have a customer named Rick who hot shots in the Rocky Mountain region. His 2005 Dodge would pull trailers from New Mexico to Montana, West to Nevada and East to Kansas and Nebraska. He contacted us because he was losing time crossing the Continental Divide near Eisenhower Tunnel. His EGT's would approach 1400 degrees and he'd have to lower his speed to get them down to 1250-1300 degrees. This loss of time affected his operating costs and ability to bid projects.
We set Rick up with a Smarty tuner to pickup some torque and help get the loads moving. A South Bend Dual Disc clutch replaced the stock unit to reliably handle the power. Next, we addressed the air part of the equation. 2004.5-2007 5.9 pistons are notorious for melting under high EGT's (1400 degrees and higher). We needed to safeguard the motor from a catastrophic failure, while improving his towing ability. A set of ARP headstuds, ATS Aurora Plus 5000 Compound Kit, ATS Arc Flow, Mishimoto intercooler, Fass 150 and Dynomite Diesel 50hp injectors were added. The result was max EGT's of 1150 degrees, while maintaining the speed limit up and over Eisenhower Tunnel. He reported back getting 2.1 miles per gallon better than when the truck was stock.
Not every truck needs to be setup like Rick's. But modern diesels leave a ton of room to improve air flow, torque, efficiency and, as a byproduct, save you money. We are often asked, how much is too much when modifying a work truck that tows 24/7. The answer is simple. Keep your EGT's under 1200 degrees regardless of how much throttle you give it. Ensure the power transfer to the ground has no slip (automatic or manual transmission) and log your fuel economy.
Take small steps, log the improvements and start with more air to lower EGT's, minor fuel upgrades and stronger parts to transfer the power.