STEPPING out of the car - the latest version of Suzuki's new small Celerio family hatchback - I couldn't help feeling just a little smug. The trip computer told me I'd just averaged 81.3mpg for the morning's drive.
I could almost taste the big block of Cheddar cheese on offer for the most frugal journey, being offered as Suzuki let the media loose on this version, fitted with an engine promising even better economy than the model that arrived earlier this year.
Light-footing the car up and down dale (and through the Cheddar Gorge en route) we nudged no more than 50mph but honestly did not hold up any of the Sunday traffic, whose drivers seemed to be enjoying the scenery as much as me.
Anyway, with an economy figure better even than the eternally optimistic one Suzuki (and all the other car makers) have to quote, I thought the cheese was mine.
Then out steps Phil from his car to announce, with the air of a man who knows he is looking at Welsh rarebit for supper: "Can anyone beat 83.3mpg?"
That's an easy one to answer. The Cheddar went to him for a result not equalled by any of the Suzuki scribblers during the whole of the three days of the driving event. Well done, Phil.
Let's stick to economy a bit longer; it is the whole point of this version of the Celerio, where for another £500 over the simple SZ3 model you find a car with an engine producing identical horsepower but promising better economy - 78.4mpg versus 65.7mpg.
The improvement comes from squirting two jets of petrol into each cylinder instead of one, allowing more control of the fuel, so less needs to be injected.
My earlier drive of the less economical Celerio gave me a decent 57mpg, but I wasn't trying so hard to be frugal that time (no cheese on offer).
Even so, top 80mpg (even trying quite hard) is an achievement and would surely find a Celerio Dualjet returning something approaching 70mpg in everyday use, given just a modicum of restraint.
But don't expect to see lots of Dualjets on the road. Drivers looking for an economical small car in the Celerio's price range (starting at £7,999 and topping out with a new automatic version at £9,799) almost always gravitate to the lower end of the price list.
The Dualjet version may make modest headlines as the car with the cleanest exhaust on sale for less than £10,000 but that brings no road tax concessions over the still pretty unpolluting model that costs a useful £500 less. They're both road tax free.
You'll still have to pay the £11.50 daily London congestion charge as even the Dualjet is not quite clean enough to qualify for exemption (which kicks in at 75g/km); so the non-eco model looks an even better bet.
It comes for £8,499 in the lower of the two levels (SZ3/SZ4) offered on the Celerio but you are unlikely to feel shortchanged. The extra £1,000 of the SZ4 merely adds such inessentials as polished alloy wheels, a black radiator grille, and slightly more practical touches - including electric door mirrors, front fog lamps and an extra pair of speakers.
But the SZ3's standard kit includes alloy wheels, air conditioning, a DAB radio and Bluetooth and a CD slot.
Its modest three-cylinder engine provides enthusiastic noises and enough urge for most needs, helped by a light clutch and gearchange.