Quote Originally Posted by LPH_UK View Post
No idea how you've managed that!

Mine appears to be linked to the original car the engine was removed from - even though the car was registered as new in 2021.
No, it is isn't linked directly to the car it is removed from.
All cars from that pre 2001 period were taxed on their engine capacity. Ie upto 1549 cc & over 1549 cc.
An IVA emissions test alone cannot determine the CO2 g/km emissions figure that a low volume car produces to position it in bands A to M that the 2001 to 2017 VED rates are charged at.
Because this g/km figure is not identifiable the tax rates simply revert to the older pre 2001 engine capacity system.
I do not know why Jim's car is cheaper on road tax, it is most likely just related to something being inputted incorrectly at the DVSA at first registration and they have simply mixed up the 6 month cost with the 12 month cost on the system.