Choosing an Audi TT as a company car is never a decision based solely on what your head says – it’s a far more emotional process than that.

But in the current economic climate, and with fuel prices rising by the day, a dose of sensible, head-led thoughts need to come into the equation.

And it’s fair to say that our entry-level TT returns some surprising figures for a car of its type (it’s a 200bhp, 150mph coupé, don’t forget).

But as impressive as near-32mpg average fuel economy is, by today’s prices it’s going to cost a fair bit in petrol.

Luckily there’s now an alter-native in the form of the recently launched TT TDI, powered by a 170bhp 2.0-litre diesel engine.

So which TT should you go for if you’ve decided that Audi’s gorgeous coupé is the car for you?

On paper, the petrol model is cheaper (£24,985 vs £26,175), although the diesel does come with Quattro four-wheel drive as standard.

And that’s where the petrol TT’s advantage ends. Everywhere else the diesel TT is better.

CO2 emissions in the TT TDI are 139g/km, which places it in the lowest 18% benefit-in-kind tax band for diesels.

The petrol emits 183g/km for a 27% BIK banding. For a 40% taxpayer, the diesel TT will cost £157 a month while the petrol weighs in at £225.

In VED terms, the petrol is £50 a year more expensive.

All of this results in the TT diesel being nearly two pence per mile cheaper to run over three years and 60,000 miles.

So end of story, right?

Wrong. Even though the diesel returns a claimed 53.3mpg compared to 36.7mpg in our TT, the fuel issue is not so clear cut.

With diesel costing five pence per litre more than super unleaded petrol, and the diesel model costing £1,200 more to buy at the front end, a driver will need to cover something in the region of 60,000 miles over a typical three-year period to recoup the extra economy offered by the TT TDI.

If a driver will cover these sorts of miles then there’s little to touch the diesel TT as a user-chooser car. But for lower mileage drivers, the petrol TT remains the car to go for.

Both versions have masses of appeal – so selecting one in the end comes down to how long your driver wants to spend behind the wheel.