'OFFICIAL fuel consumption figures have always been regarded with some caution. Probably most people realise that there is no completely reliable way to know what distance a car will achieve on one gallon of fuel and that the official figures can only be, at best, a guide.

As more cars feature on-board computers, with both instantaneous and average fuel use measurements, a clearer idea of the truth can emerge – and in my experience is often a significant departure from the official printed figures.

And although it is fair to say that they can be lower as well as higher, the tendency is for average readings from the car itself to be lower than those claimed beforehand. This is a source of frustration for everyone involved in choosing cars to buy because comparisons between models will often take fuel consumption into account. Yet despite the fact that benchmarking is carried out by the manufacturers in an attempt to level the playing field it is very noticeable to me that these figures do not tell anything like the full story.

Take similar journeys at similar speeds but with and without passengers. Two or three extra people and a bit of luggage reduces the mpg by as much as 10% and this is particularly noticeable on smaller petrol-engined cars. Here I have noticed a reduction from about 45mpg to 40mpg or less. In contrast, the difference is negligible on larger diesel- powered cars. Yet the irony is that it is the smaller cars that are chosen by those for whom low fuel consumption is a major criteria for choice in the first place.

In the used car market, where most drivers have to buy their own fuel, consumption plays a major part in whether the car is considered a successful purchase or not. Fuel is by far the biggest ownership cost after depreciation for the average driver, and yet countless people must be disappointed when they discover their real consumption figures, unless they constantly drive in a style close to the official test conditions, which is nigh on impossible on today's roads.

The running cost figures in CAP Monitor reveal the proportion that fuel takes up. Take a Vauxhall Vectra 1.8 LS. Of a Monitor forecast of 27.7 pence per mile over three-years/ 60,000 miles the fuel element is 9.37 ppm, about a third of the total. Compare that with the service cost of 0.73 ppm. On a smaller-engined Focus, the 1.6 LX, fuel makes up 8.75ppm out of a total of 23.91ppm over the same period. Here, servicing is just 0.58ppm.

There must be a lot of out-of-pocket used car owners out there. The best advice, therefore, is to turn off the air con, reduce weight as much as possible, keep the windows closed and avoid carrying passengers. You may get too hot and become unpopular and lonely but your mpg will at least come close to official figures.

Individuality pays off as punters look for more

It is clear, when observing at auction, just how determined the trade buyers are when they are after something a bit different.

I see it every time a vehicle gets near the hall entrance before perching under the rostrum, to be surrounded by an interested huddle of bidders. The bidding tends to be brisk as it quickly emerges that everyone wants this car.

These cars can vary by manufacturer, bodystyle, colour and age so there really is no clear pattern to what is wanted by the buyers. I watched a Toyota Corolla estate and a SEAT Ibiza diesel recently. These seem to have something like cult status, so while they are not normally especially sought after, in the right sale they are unusual enough to attract plenty of attention and interest.

The lesson may be that the public's taste is changing and that the new culture of individuality means forgetting the run-of-the-mill in favour of something of quality, affordability and with a certain 'look twice' flair.'