Telling the DVLA about engine conversions

mx400-engine-bayOne of the things that people have asked is “How do you inform the DVLA of an engine change?”

I’ve heard various tales of the DVLA not being convinced and extra evidence having to be produced, but my experience was surprisingly easy. Now, I only have my experience to base all this on, and I suspect that there’s an element of luck involved as well, but I sent the following letter to the DVLA, along with all the documents identified therein.

“I am writing to you to notify you of a change in engine size to my Mazda MX-5, registration Jxxx xxU. The engine was sourced from a Lexus LS400, registration Sxxx xxU.

Please find enclosed:

  • The V5 for Jxxx xxU, with section 7 completed to reflect the change in engine.
  • A photocopy of the receipt for the purchase of Sxxx xxU.
  • A photocopy of the V5 I held for Sxxx xxU, prior to disposal of the vehicle after removing the engine.
  • A photocopy of section 9 of the V5 for Sxxx xxU, showing the transfer of the vehicle to a dismantler
  • A certificate of destruction for Sxxx xxU
  • Confirmation from the DVLA of the transfer of Sxxx xxU

I trust that this should be enough of the necessary evidence as detailed on your website at

Please advise if you require anything else.”

v5A few weeks later I had a nice new V5C on my doormat, for a 4.0 Litre MX5! 🙂 Simples!

ARDS test


To be a racing driver, you need a race licence! And that’s what this day  was all about. By this point Caterham have done a great job of instilling all the information required to pass. In principle, all that is now required is to sit an exam (including questions on flags – for which there is no room for error!), and to drive an instructor round Castle Combe circuit without throwing it off the tarmac.


The day was split into four quarters, with groups rotating through four activities. As well as the written exam and the driving assessment, Caterham had also arranged a session on the skid pan, as well as instruction on preparing the car for competition.