from 14/01/2024

Eligible cars:

  • Alfa Romeo 155 V6 TI
  • Mercedes 190E
  • Mercedes C-Class
  • Opel Calibra V6

All year models and versions of any of the above are permitted.

  • Motor: Yellow label 20.5k Flat-6 only.
  • Motor mount: 0.5mm offset (grey) long-can only.
  • Rear wheels can be upgraded to 15.8 x 8.2mm or 15.8 x 10.2mm air-hubs (vented or solid).
  • Front wheels can be upgraded to 15.8 x 8.2mm aluminium only. Magnesium version not permitted.
  • Rear tyres: Standard C1 code 1228 only.
  • Front tyres: free choice.
  • Pinion: 5.5mm 9t brass only.
  • Solid steel/stainless steel axles only.
  • Maximum track width front/rear: 61mm. Wheel/tyre can protrude beyond body to achieve this width.
  • All other parts: free choice.

Please note that Lexan interiors/windows and weight/ballast are not permitted in this class.

Additional information for DTM.

  • The Alfa Romeo 155 V6 TI is available in many different variants. Of these, the 1996 version (CA45) is arguably the best as the guide to back axle measurement is longer.
  • C1 tyres, whilst very straightforward to true, are also very hard, so will benefit from lots of oiling to soften them up. Also, they only need a very light skim as the 1228 version is almost exactly the right size out of the box.
  • The only crown gears that will mesh correctly with the Flat-6 motor in an offset mount are the range of offset crown gears. These are available in:
    • Aluminium: Lighter but less durable.
      • GO23/24/25/26/27/28/29/30-al. 
    • Bronze: Heavier but almost indestructible.
      • GO23/24/25/26/27/28/29/30-bz.
    • Modular: More expensive, but in theory less friction.
      • GM23/24/25/26/27/28/29/30o.
    • Modular gears also require GMF55 stopper.
  • The best gear ratio for this class is 9/23.