MJ Diesel Speed Shop

Medium Duty Diesel Truck Specialists

Certified Technicians

Our technicians are certified to rebuild, replace, repair and upgrade all medium duty diesel engines including Cummins, Powerstroke and Duramax.

Now Hiring

We stand firm behind the belief that how much you put in is what you get out. We have lots of room to grow and the industry we engage with is one that is extremely rewarding for the right individuals. We are a rapidly expanding company and are looking for a long-term, full-time commitment to grow with us.

Diesel Performance Specialists

Whether you have a Ford, Chevy or Dodge medium duty truck, we can improve the performance of your vehicle with adding a turbo or a transmission upgrade.

Diesel Injector Testing and Repair

Ship us your diesel injectors and we will test and match them to their proper specifications.  We can also replace and rebuild your existing diesel injectors.  Call 678-343-2762 for more information. 

Caffeine & Octane

North America’s Largest Monthly Car Show

MJ Diesel has been part of the Caffeine & Octane monthly car show since 2019 and continues to help promote and be an integral part of its’ success.  Every month, 2,500+ cars and 15,000+ fans attend the show.  The show is free to attend and free to exhibit.  Visit our spot once the show opens back up in the coming months.

Caffeine and Octane is held the first Sunday morning of each month at Perimeter mall in Dunwoody, GA, just north of Atlanta.

The next Caffeine and Octane is the first Sunday each month from 8 to 11:30 AM at Perimeter Mall, Dunwoody, GA.

We will be bringing two new projects to the show! We’re so excited to reveal our Argosy Rehab Project for Caffeine and Octane along with our LML Duramax Street Performance truck.

Recent Media

Social Distancing Car Show

May 16th Virtual Caffeine & Octane live from the Garage.


MJ Diesel Blog

Latest News & Updates