Over Diemmax

2015 Diemmax started converting V12 BMW (car)engines. Customers in the 520-600 HP segment were designated 2 maintenance-sensitive V6 petrol engines or heavy converted diesels. Diving into this niche turned out to be a hit. Demand for the V12 was enormous.

The interest in the segment was so great that we decided to develop an entirely new engine. A compact and aluminum V12 diesel 100% developed for the maritime sector.

After more than 2 years of building and development, the first test runs will be made in December 2020 and a prototype has now been run on the test bench for hundreds of hours.

Our Mission


We want to be the most desired and successful supplier of premium line marine engines in the world.


We have the ambition to be an innovation leader in the field of safety and the environment. Our ambition guide us on our journey and ensure that we are on the right track.

Our Vision


We want to deliver premium engines for the marine market, thereby enriching people's lives for all our tomorrows.


We focus on the challenges out customers face and we strive to provide sustainable solutions for needs which are essential to human life.

Our Story

Over the Years

  • Started 2001 as a boat maintenance service and marinizing different types of diesel engines
  • Started remanufacturing and marinizing BMW and Audi diesel engines
  • Change focus to develop a new engine for a gap in the market
  • Presenting the prototype V12 on exhibition Boat in Düsseldorf
  • Presenting preproduction model V12 on METSTRADE
  • Starting development special Electronic Control Unit (ECU)
  • Switch from machine parts to casted parts
  • Final Phase testing the V12 with the new ECU
  • Start serial production V12

Premium Engine line

Diemmax Range Goals

From mid-2021 we have a complete range of marine engines. In addition to our flagship (the V12), we are developing a 6-cylinder and a 4-cylinder engine.

We are of course proud that parties such as JLR work with us at the highest level. The 6-cylinder sale will be ready from the first quarter of 2021 and our flagship will be launched more widely from Q3 2021. The 4-cylinder follows in 2023.

Interested in our products?

plan an online informative meeting with one of our certified suppliers:

12 cylinder

Aluminum cylinder block
Titanium, carbon fiber
Compact design
  520 until 600 Hp (382 until 440 kW)

6 cylinder

Aluminum cylinder block
Titanium, carbon fiber
Compact design
250 until 350 Hp (184 until 257 kW)



520-600 HP

The lightweight (every kilo counts) and smooth running Diemmax V-12 diesel engine is an extreme advantage in his class. Powerfull, an amazing low-end torque and no noticeable turbolag, and very quiet!


250-350 HP

The Diemmax D6LR delivering leading acceleration and top end responsiveness. The peak torque is available almost immediately after accelerating from 1,750 RPM and on.  


180-260 HP

This highly competitively priced 6 Cylinder inline engine is specially built to replace your worn or outdated gasoline or diesel engine.

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