About Doc's

EST. 2020 // NORTHWEST OHIO

SMALL TOWN ROOTS, BIG DREAMS

Named for Grandpa Doc. Built on his work ethic. We make maintenance easy for truck & vehicle owners in all 50 states, shipping from our new 42,000 sq ft HQ in Bryan, Ohio.

Read Our Story Shop Parts

FOUNDED 2020 42,000 SQ FT HQ 500,000+ HAPPY CUSTOMERS

Meet Grandpa Doc

Before there was Doc’s Diesel, there was Doc.

He farmed the land. He ran a dump truck business. He owned a Ford dealership. Then he found his true calling in auto parts.

Doc worked hard, took care of his people, and loved his community. He passed away when Max was a kid, but the values he lived by were passed down and Max carried them forward.

His name is on every box we ship. We intend to keep it worth something.

WHY I STARTED DOC'S

I started Doc's Diesel online in 2020 to make doing maintenance just a bit easier. Dealer replacement filters cost a fortune, and parts were hard to find or from brands you couldn't trust.

So we built what guys wanted: filters that meet or beat OEM specs, lab tested and sold direct.

Since then, we've expanded into more of what your truck needs from oil and additives to brakes, hubs, and more.

Grandpa Doc taught us that hard work and taking care of people go hand in hand. Today, we're 50+ strong, shipping to all 50 states. He'd be proud of what we're building.

Welcome to Doc's.

Max Nihart

Founder & CEO, Doc's Diesel

Maintenance Made Easy

Every filter your truck needs, in one kit, shipped fast. Less time searching. More time wrenching.

Find parts for your truck

No Dealership Markup

We sell direct. No middleman, no dealer pricing. OEM-spec quality at a fair price.

Shop diesel filters

Third-Party Tested

Independent labs check our filters against OEM specs. We share the results because trust matters.

See how we test

Family Run, Small Town

Named for Grandpa Doc. Built in Bryan, Ohio. Real people pick up the phone and stand behind every order.

Meet the crew

How We Got Here

The Story of Doc's Diesel

We've outgrown our space three times in five years. Here's how it happened.

2020

Doc's Diesel Launches

Max Nihart starts Doc's Diesel in Bryan, Ohio, with one mission: make truck maintenance easy.

2021

Complete Filter Kits

We focused on kitting together everything you need for a filter change and started independently testing every filter line through labs like SGS and IBR.

2022

1,500 Square Feet

The whole operation fits in just 1,500 sq. ft. As the business grows, Max starts building out the team and laying the foundation for what’s next.

2023

A Building Worth Saving

A building comes up for sale with half of it burned down. We save the other 6,000 sq ft and plan an addition. Our core team comes together, and we’re now serving thousands of diesel owners across the country.

2024

Building Momentum

The addition is done, and we double our space. More customers come back to Doc’s for each service interval, making us part of their regular maintenance routine. The team grows to about 20.

2025

Doubling Down

We add new product lines and double the team to about 40. We give away a RAM 2500 6.7L Cummins. And we prep to move into our new 42,000 sq ft HQ.

2026

What's Next

The new HQ is up and running. Our lineup now covers brakes, hubs and gas vehicles too. And there's room on our 15 acres to grow again. The story continues..

Ribbon cutting in front of the new Doc's Diesel HQ in Bryan, Ohio

// Our New HQ

Built in Ohio

In 2025 we became the first company to build in Bryan's North Industrial Park. Our new headquarters sits on 15 acres at 701 Brunicardi Way. More room means deeper stock and faster shipping to all 50 states.

Thanks to JobsOhio, the Regional Growth Partnership and the Williams County Economic Development Corporation for helping make it happen. Read the announcement.

1,500 sq ft

2022. One small room. Boxes stacked on the desk. Max packing orders himself.

6,000 sq ft

2023. Half of a burned building, saved and made our own.

12,000 sq ft

The addition doubles our space. The team grows to about 20.

42,000 sq ft

2025. Our new HQ on 15 acres in Bryan's North Industrial Park.

42,000 sq ft HQBryan, Ohio

15 AcresRoom to grow

First to BuildBryan North Industrial Park

50+ EMPLOYEESWORLDWIDE

All 50 StatesShipped from the Midwest

SGS + IBRLab tested

Est. 2020Family run

42,000 sq ft HQBryan, Ohio

15 AcresRoom to grow

First to BuildBryan North Industrial Park

50+ EMPLOYEESWORLDWIDE

All 50 StatesShipped from the Midwest

SGS + IBRLab tested

Est. 2020Family run

01

Unloading a trailer of inbound stock at Doc's Diesel

Sourcing

We work with vetted manufacturers who build to OEM specifications. No mystery suppliers, no shortcuts.

02

SGS + IBR Lab Testing

Independent labs SGS and IBR test our filters for micron rating, efficiency, materials and fit.

03

Gloved hands inspecting a Doc's Diesel fuel filter

OEM Spec Verification

If a part doesn't match OEM tolerances, it doesn't make our catalog. Our filters meet manufacturer warranty requirements, so your warranty stays intact.

Welcome to Doc's

Right parts. Right now. Right to your door.

Max NihartFounder & CEO

Shop Diesel Parts

Filters, oil, brakes and hubs for Cummins, Powerstroke, Duramax and EcoDiesel.

Browse the catalog

Shop Gas Parts

Filters and maintenance parts for gas vehicles, built to the same standard.

Browse gas parts

Become a Wholesale Dealer

Fleet pricing and bulk stock for shops, dealers and fleets.

Apply now