Proposed Vehicle Excise Duty (VED) changes intended to reduce CO2 emissions from cars will have little impact unless driving behaviour changes as well, according to research from the Institute of Advanced Motorists (IAM).

Although many manufacturers have highly efficient “eco” versions of their cars available, many drivers will unwittingly lose the benefit of the technology through poor driving habits.

The following examples of common errors by drivers increase fuel consumption significantly:

a. Under inflated tyres – tyres that are 20% underinflated use three per cent more fuel

b. Roof storage – wind resistance causes use of up to 20% more fuel at 70mph

c. Air conditioning – uses up to 10% more fuel

d. Aggressive driving – uses 15% more fuel

e. Speeding – travelling at 80mph uses up to 15% more fuel than 70mph

f. Short journeys – the first two miles use up to 100% more fuel

Taken together, all these items can increase fuel consumption, and CO2 emissions, by up to 45%.

“If the government is serious about getting motorists to reduce CO2 emissions, the IAM says more investment in driver education and information is needed, rather than extra taxes that motorists suspect are more about revenue-raising than improving the environment,” Tim Shallcross, IAM Head of Technical Policy and Advice, said.