VETERAN OWNED & FAMILY OPERATED

 Your truck is your livelihood and the vehicle that carries you and your loved ones every day. At Knox Performance Diesel and Offroad in Killeen, Texas, we treat every truck with that responsibility in mind. We specialize in professional diesel diagnostics, repair, and off-road performance for Powerstroke, Cummins, and Duramax trucks, focusing on quality-first repairs, honest communication, and doing the job right the first time.

We moved back to the area in 2019, to fulfill the dream of starting a diesel repair shop.  What started out as a husband and wife team has grown into a bigger family.

• Katie (wife) - From co-owner and everyday shop operations to flying with the Navy Reserves.  (GO NAVY BEAT ARMY).   The voice you hear when you call, the one juggling schedules, parts, and priorities to keep things moving  and nothing (too important) catches fire.
• Britt (husband) - ARMY.  He's a man of few words unless the conversation is about our daughters or diesel trucks. He's also the muscle behind the operation and the reason we never have to guess what's wrong with a truck.  His standards, skill, and no-shortcuts mindset are a big part of why we’ve earned the reputation we have today. 
• Walt (dad) - Before Knox Diesel, Walt spent his life as a cowboy, ranching sunup to sundown, seven days a week. That discipline and dedication didn’t fade when he came into the shop. He leads by example, teaching us every day that real strength comes from consistency, humility, and hard work.  Every shop needs a solid foundation. Dad is ours.   
• Jared - Retired ARMY (20 YEARS), Started as a customer to a best friend.  Now he's head of operations and the reason our shop runs smoother than your truck ever did.   His leadership and discipline keep Knox Diesel operating at the highest standard. 
• Dakota - He's from Illinois but we don't hold it against him. He drives a dodge (yee yee) and we DO hold that against him. He's a huge fan of Texas BBQ though, but hates ranch. 
• Natasha (niece) -   Full-time high school student and part-time shop apprentice, learning the ropes of diesel repair while balancing her studies. She’s proof that hard work and ambition start young. 
• Bruce - Shop cat. She showed up and never left

  We focus on accurate diagnostics, quality repairs, and treating every truck as if our own family were riding in it.

Knox Performance Diesel and Offroad is a bumper-to-bumper diesel repair shop serving Killeen, Texas and the surrounding Central Texas area.

Diesel Repairs
From oil leaks, electrical and emissions faults to complete vehicle diagnostics and full engine rebuilds, we handle complex diesel repairs for Powerstroke, Cummins, and Duramax trucks with a quality-first approach.

Diesel Maintenance
Bumper-to-bumper servicing including oil changes, transmission services, coolant flushes, and preventative maintenance designed to keep work trucks and daily drivers reliable.

Performance & Off-Road
Performance upgrades and off-road fabrication including head studs, turbos, injectors, lift pumps, exhaust systems, custom suspension fabrication, lift kit installs, traction bars, bumpers, winches, and light bar and pod installations.