What are the calculations for CO2 emission vehicles? What rates apply?

CO2 emissions: appropriate percentages

The exact CO2 figure is always rounded down to the nearest five grams per kilometre (g/km).

For example, the car’s logbook gives CO2 emissions of 168g/km. Rounding down this comes to 165g/km which is an appropriate percentage of 21% for 2009-10.

The percentages must be adjusted for diesel and low emission cars (see below).

CO2
emissions(g/km)

 

2005-06 to 2007-08

2008-09 to 2009-10

CO2
emissions(g/km)

 

110-114

 

10%

110-114

115-119

 

10%

115-119

120

 

10%

120

125

15%

15%

125

130

15%

15%

130

135

15%

15%

135

140

15%

16%

140

145

16%

17%

145

150

17%

18%

150

155

18%

19%

155

160

19%

20%

160

165

20%

21%

165

170

21%

22%

170

175

22%

23%

175

180

23%

24%

180

185

24%

25%

185

190

25%

26%

190

195

26%

27%

195

200

27%

28%

200

205

28%

29%

205

210

29%

30%

210

215

30%

31%

215

220

31%

32%

220

225

32%

33%

225

230

33%

34%

230

235

34%

35%

235

240+

35%

35%

240

Diesel cars

  • The basic rule is to calculate as for a petrol engine and add 3% to a max of 35%.
  • If the car has CO2 emissions of 120g/km the appropriate percentage for 2008-09 is 10% plus a 3% addition i.e. 13%.
  • If the cars CO2 emissions exceed 120g/km, round down (as you would for a petrol engine) to arrive at the nearest 5% and add 3%.
  • See Company cars for exact details of the surcharges as they apply to different types of diesels.

Discounts for low emission cars

  • When a car has CO2 emissions of 120g/km or less the appropriate percentage from 2008-09 is 10%.