EDINBURGH motorists are some of the cleanest in Britain, with levels

of poisonous car exhausts lower than when MOT testing was introduced a

year ago, it is revealed today.

In other parts of the country, carbon monoxide emissions are worse

than 12 months ago as millions of drivers put off servicing to save

money.

Just one ''grossly polluting'' old banger produces as much carbon

monoxide as 40 ''clean'' cars.

But in Edinburgh, where 6000 vehicles were tested by the RAC using the

latest infra-red technology, the level was lower than at other sites

round Britain.

Despite the recession, only 5% of Scottish motorists have cut back on

vehicle maintenance, compared to a national average of 12%.

According to Dr Jeremy Vanke, environmental affairs manager at the

RAC, the reason Scottish drivers have improved the environment is

because of their dependency on vehicles.

''Scotland is not as well served by public transport and many people

live in remote areas and depend on their cars,'' he said.

The survey shows a general increase in the amount of carbon monoxide

now being pumped on to Britain's streets.

Around 20,000 vehicles were tested in the first week of November,

exactly a year after new MOT tests were introduced, and compared with

vehicles tested during an identical exercise last year.

The survey revealed that 60% of vehicles are in the cleanest category

for emissions of carbon monoxide but 50% of pollution comes from just

13% of vehicles on the road.

Dr Vanke said: ''Sadly, in the current recession, drivers are trying

to save money by cutting back on servicing and so their cars are

becoming dirtier.