Audi‘s most basic diesel A3 falls below the golden 100g/km CO2 mark, making it an attractive choice for business car buyers.

Owners of the three-door 1.6-litre 105hp will pay 13% benefit-in-kind tax, or £40 a month as a 20% taxpayer, while VED is nothing. The news gets even better in 2012, when only cars under 100g/km will qualify for the lowest 13% BIK banding available to diesel cars.

Residual values aren’t bad at 38.6% and you’ll get a satisfying 74.3mpg according to official figures; cost-per-mile works out at 39.7p.

All other versions of the 1.6 TDI stay at 109g/km CO2. Mated to a five-speed manual transmission only, the gearbox is challenging especially in lower gears where its near-impossible to move off in second. Other than that, the A3, while being one of Audi’s most basic, makes an awful lot of sense as a lower-medium car.

Audi A3 1.6 TDI 105hp 3dr 5sp
P11D price £18,260
Model price range £16,085-£24,275
Fuel consumption 74.3mpg
CO2 (tax) 99g/km/(13%)
BIK 20/40% per month £40/£79
Service interval 9000-19,000mls
Insurance group 18
Warranty 3yrs/60,000mls
Boot space (min/max) 350/1080 litres
Engine size/power 1598cc/105hp
Top speed/0-62mph 121mph/11.4secs
On sale January 2010
Score 7/10
Verdict You can’t go far wrong
with a 99g/km Audi