We've just received the email with the results of this year's MPG Marathon event, a 370-mile, two-day rally to find the most economical cars on sale today.

Although we didn't quite hit the 'official' claimed 52.3mpg figure in the Jaguar 2.2D, we did manage to average 51.1mpg - no small feat considering the car's 1745kg kerbweight, automatic 'box and our minimal eco driving experience.

Surprise, surprise, it was the snarling Vauxhall VXR8 that picked up the award as the car with the greatest percentage improvement on its claimed economy. Its drivers managed to eke out 32mpg from the 6.2-litre motor, an improvement of 53 per cent compared with the manufacturer's pitiful official 21mpg figure.

Interestingly, the Peugeot 3008 Hybrid4 was the car we were expecting to reach in excess of 70mpg, but it only managed 57.3mpg, some way short of the manufacturer's 70.6mpg figure. This may, however, have had something to do with a flat tyre its drivers were greeted with on the second morning - I still like to think that the tyre was slashed by over-zealous eco competitors&

The car with the greatest mpg figure during the event was the Smart Fortwo CD1 Coupe Passion, which hit an incredible 99mpg, followed by the Skoda Octavia Greenline, which hit 86mpg - improving the manufacturer's claimed 74mpg figure by 15 per cent.

So what have we learnt?  Well, if you don't drive cars economically for a living - as many of these old boys do - you won't achieve any where near the claimed manufacturer mpg figures in the real world.

Secondly, that driving as we did for two days not only proves dangerous in certain occasions and massively compromises traffic, but that it's also incredibly challenging.

I was really looking forward to spending 370 miles in the Jag, but if I'm honest I still don't know what it's really like to drive...

Here's a list of the top five most improved vehicles -

1) Vauxhall VXR8 - 53 per cent improvement at 32mpg compared with 21mpg claimed2) Volkswagen Golf R - 48 per cent improvement at 49mpg compared with 33mpg  3) Suzuki Swift 1.33 DDiS - 28 per cent improvement at 86mpg compared with 67mpg claimed4) Peugeot 308 CC - 28 per cent improvement at 74mpg compared with 58mpg claimed5) Saab 9-5 Aero 2.0 T - 27 per cent improvement at 44mpg compared with 34mpg claimed