Why are newer bluemotion tech (BMT) Calis more expensive to tax?

[AndyFromTheBrac]

So my 2011 non-BMT Cali costs £230 a year. We've currently got a loaner (63-plate) BMT whilst ours is in for the roof panel repair, so I looked up at https://www.vehicleenquiry.service.gov.uk/ when I taxed mine and found it's £265. They're both 180 DSG and loaner isn't 4motion.

Not sure what the theory is behind that?

Also (and in an entirely subjective non-scientific test of me driving back from my mums) I found that I could better 41mpg average in my non-BMT but the newer version managed 38 - Driving at the same 67MPH / 300 miles non-stop journey. Margin of error (driving/computer etc) probably covers that I suppose. I'd still expect better (no bike rack and lighter load on the loaner, too). Maybe the less miles on the loaner & perhaps needs to loosen up, but it's a '63 not a '15,,,Odd??

 

[andyinluton]

2011 cali registered as a motor caravan - flat rate tax respective of emissions. Rules changed 2013 & as california is completed by the original manufacturer it is taxed based on emissions.

A 3rd party conversion reregistered as a motor caravan or any other vehicle "changed" after manufacture would be taxed on the same flat rate as your 2011 This is as the original emissions test of the base vehicle is now irrelevent & no one currently expects converters/ bodybuilders etc to get new emissions test done.