Diesel Spec – North America’s Leader In Truck Tuning

March 2022

Diesel Spec is the largest performance shop for heavy-duty trucks in North America with 485 retailers in the USA and Canada that perform over 5,000 truck tunes each year. 

Tuning is the process of fine tuning the software in the truck’s ECM module, with the end result of creating more power, greater response and less fuel consumption.  Diesel Spec offers 4 types of tunes:

•High Performance


•Fuel Economy


The High Performance tune is the choice for truck pulls and racing.  The Performance Tune provides extra power for heavy loads and pulling mountains.  The Fuel Economy tune does exactly what its name implies, and the Off-Highway tune eliminates horsepower robbing add-ons.  Truck owners are urged to check their state laws, however before having an off-road tune performed.  The tune itself can be done at any of Diesel Spec’s 485 retailers in about 2 hours.  The customer decides which type of tune they would like performed, then a tuning module is plugged into the truck’s ECM and the tune is performed remotely from Diesel Spec’s Montreal, Canada headquarters.  Each tune carries a 30-day satisfaction guaranteed warranty and a one year reflash in case the ECM is reset at a dealer.  Both warranties are included in the price of the tune.  Most customers experience a 5-20% (about ½ mile per gallon) gain in fuel economy.  Tunes are available for nearly every engine, including: CAT, Cummins, Detroit, Isuzu, Mercedes, PACCAR, AND MaxxForce. Updates are available for all modern engine versions. Diesel Spec also does tuning for farm tractors and off-road equipment.

Diesel Spec sells high performance parts including turbos, exhaust manifolds, intake manifolds and crank dampers.  The company has two dynometers at their five million dollar facility in Montreal for their customer’s convenience.

The following are what satisfied customers have to say about their Diesel Spec tune:

Menick LeBeau, Quebec: “Thanks to the Diesel Spec team for the professional work!  Not only is my truck more fun to ride in since you upped its performance, but I also make fuel savings of 1 mile per gallon.  I recommend all truck owners visit Diesel Spec.”

Luis Gauget, Mexuscan Cargo, “Thanks for bringing my engine back to life!  100 horsepower more and fuel savings of 10%.  A tremendous investment.”

John, JNB Heavy Haul, “We at JNB Heavy Haul need all the power we can get without sacrificing fuel economy.  More than 30 trucks done and very satisfied.  Diesel Spec delivers big in both.”

Tyler, Dingman Trucking: “We did a tune on a Caterpillar bridge engine.  Truck now pulls great and is good on fuel.  CAT engine was lazy before.  Thanks Guys!”

Doug Ruddick, Texas: “2007 Kenworth W900B with Caterpillar C-15 MXS twin turbo.  I have the economy tune on my truck and right away you can see the difference.  The truck pulls better, uses less fuel and seems to run a little cooler as well.  I have had one truck done with Finning and one with Diesel Spec and Diesel Spec is the way to go.”

FedEx Canada: “Thanks to Diesel Spec, my Cummins ISX runs with more power and better fuel economy!  Great place to deal with smiling faces.”

If you would like to take your truck from mild to wild, give Diesel Spec a call at 855-932-0060.