Mazda3: company car choice

Which bet is best for company car wheels

One of the added benefits of having a stop/start system fitted to a car is it helps lower the CO2 emissions as well as improve fuel consumption so, is the iStop version of the Mazda 3 a good bet if you are a company car car driver?

First up, at 159g/km it comes under the critical 160g/km barrier where companies are hit hard for tax. Over 160g/km of CO2 and the company can only write down 10% of the car's value as allowance, whereas cars with emissions below 160g/km a company can write down 20% of the car's value.

But what are the other petrol choices in the range? There's a 2.0-litre petrol that comes with automatic gearbox available in TS2 or TS2 Nav trims, or the 1.6-litre petrol that comes in all eight trim levels including the top Sport trim. The 2-litre petrol has emissions of 175g/km which puts it the wrong side of the 160g/km mark, while the 1.6-litre petrol emits just 149g/km, so slips into the 17% BIK band compared to the 19% BIK band for the 2.0-litre Sport with iStop.

However, in terms of actual company car tax, for a 20% tax rate payer the smaller petrol engine Sport will currently cost just over £50 a month, while the 2.0-litre version is £10 more a month at £60.75. Not a lot more and it's quicker (10.1 seconds to hit 60mph compared to 11.8 for the 1.6), faster (top speed of 128 versus 114mph) and nearly as frugal (a claimed 41mpg versus 44mpg). So in terms of maximum car for your company car buck, the iStop version does look compelling.

If you are thinking the top diesel version (2.2-litre Sport model) is a cheaper bet then think again. A 20% tax payer will pay just over £70 a month despite it emitting 149g/km CO2. The diesel version has a higher P11d value (almost £2k more) and attracts a higher BIK banding compared with the petrol. The upside is as you'd expect - average fuel consumption is a claimed 50mpg.

Current mileage: 2,734

Average mpg: 32.3