Sorry mate, I was geting confused there. To be fair, your cars probably registered correctly and your paying the right amount of tax. Some people have been lucky and a DVLA mix up means their on the old scheme.
If the car was registered before 01 March 2001, then you would be on the old scheme...
Cars registered before 1 March 2001 (based on engine size)
Private/light goods (TC11)
Engine size (cc)
12 months rate
6 months rate
Not over 1549
£ 125.00
£ 68.75
Over 1549
£ 190.00
£ 104.50
Cars registered on or after 1 March 2001 (based on fuel type and CO2 emissions)
The rates shown only apply to cars that have been type approved in category M1 and registered on the basis of CO2 emissions measured in grams per kilometre (g/km) driven. These details are shown on the registration certificate (V5C).
From 1 May 2009, Vehicle tax rates for cars registered on or after 1 March 2001 are split into 13 bands depending on CO2 emissions. The amount you'll pay depends on which band your car is in. The lower a car’s emissions, the lower the vehicle tax payable on it.
These bands and rates apply to all tax discs bought from 1 May 2009 onwards.
Petrol car (TC48) and diesel car (TC49)
Band
CO2 emission (g/km)
12 months rate
6 months rate
A
Up to 100
Not applicable
Not applicable
B
101-110
£35.00
Not applicable
C
111-120
£35.00
Not applicable
D
121-130
£120.00
£66.00
E
131-140
£120.00
£66.00
F
141-150
£125.00
£68.75
G
151-165
£150.00
£82.50
H
166-175
£175.00
£96.25
I
176-185
£175.00
£96.25
J
186-200
£215.00
£118.25
K*
201-225
£215.00
£118.25
L
226-255
£405.00
£222.75
M
Over 255
£405.00
£222.75