About Diemmax

2005 Diemmax has started building 6 cylinder marine engines and converting V12 engines for marine use. Customers in the 520-600 HP segment were designated to maintenance-sensitive V8 petrol engines or heavy 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 in 2015 decided to develop an entirely new engine. A compact and aluminum V12 diesel 100% developed for the maritime sector.

After more than 4 years of building and development, the first test runs are made in December 2020 and a prototype has now been run on the test bench for hundreds of hours. 

Since 2021 our range has been expanded with a new twin turbo 6 cylinder engine.

Our Mission


We want to be the marine engine manufacturer who continues to improve through innovation and technology.

Our Vision


In the coming years, we will set a new standard in marine engine power for the customer and let them experience comfort.

Our Story

Over the Years

  • Started 2001 as a boat maintenance service and marinizing different types of diesel engines
  • Started remanufacturing and marinizing 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 of electronics to improve our customer expierience
  • Switch from machined parts to casted parts
  • Final Phase testing the V12
  • Start serial production V12

Premium Engine line

Diemmax Range Goals

From mid-2021 we have a complete range of marine engines from 250 till 600 hp. In the future we will expand our program until we have a complete range of engines.

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 till 600 Hp (382 till 440 kW)

6 cylinder

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

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