just been watching top gear...

...economically. Well done :-)

you are derv and i claim my 5 pounds :)

Could be! ;)

As others have said, it's conservation of energy combined with acceleration sense that goes the distance. Doesn't mean granny-like acceleration (this is a bad thing), but it does mean lifting off plenty of distance from a hazard. From mid 50s, lifting off at the four hundred marker for a hazard usually means it's second or third gear speed if the hazard is clear, or much less braking if I do need to decelerate.

Stopping is a big no-no. Speed changes is a no-no. Cold running is a no-no. Redlining it is a no-no too. Minimise all three where you can. Leaving to get to work half an hour earlier might make quite a bit of difference. Letting the speed bleed off up a gradient, letting it build the far side - good things. It's surprising how letting the speed drop by a big margin going up a hill makes a big difference, but all you're doing is converting one form of energy (kinetic) into another (potential), without chucking lots more power into the equation. If you shove more energy into the equation (donk power), you don't gain any more potential energy (you don't go any higher) nor do you lose as much kinetic energy (speed, velocity, meh) - but you do burn more fuel.

Keeping the engine revs to the absolute minimum is also a no-no. It's a combination of revs and load that produces power and burns fuel, not just revs. Okay, sure; same power at a higher engine speed means more friction, but you might find 30 in third is more economical than in fourth, even though it sounds thirstier... For gradients, going up, slowing down makes a big difference, depending on what's behind you.

In busy traffic, match speed with the trucks at the three second distance point in the dry - decent enough distance from the Yorkie in front, some slipstream benefit. Doing the overtaking lane 60 - 80 - 60 sketch is bad for economy...

Over my usual commute, the 9-3's average speed (door to door) is usually only in the mid 30s; blame York's busy traffic for that. Long haul stuff is much higher. If I am being deliberately economical (don't exceed 2,000 rpm, lift off 500 yards from hazards, nuts to anybody behind at gradients) and in warmer weather I see ~40 mpg over my 27 mile commute (5 mile city, 5 mile dual carriageway, 17 miles A-roads at the speed limit). Slightly less economical my petrol 9-3 shows ~38 to the gallon. Same average speed. The car's official combined cycle is 34.9 mpg and it's Extra Urban figure is

45.6. Record high is just over 42...

Now official fuel consumption figures are a bit of a nonsense really, but of the last three similar sized cars (Accord 1.8, Saab 9-3 2.2 TiD, Saab 9-3

1.8t) my average and highest mpg figures have been 110% of the official combined cycle and 122% respectively. I only see the best mpg figures on long trips in the summer. So I don't believe Conor's 60 mpg and "thrashing it" claim. Sounds like Saxo VTR Optimism to me.

So what's the usual range of your machine and do you fancy the Top Gear range challenge? The official range of mine would be 58 litres @ 34.9 mpg being 445 miles. I'm thinking for the MINI One, hmm, 50 litres at 43.5 mpg meaning 478 miles.

No you don't. My OBD-II logging showed that the Ka needed 7% less average cruise control throttle input over the A64 / A1, both directions, when following a HGV at the same pace at the 3 second point. That's an average over nine months of logging. Best case was coming from Leeds to York along the A64, where if I was inside three seconds, the Ka didn't need any throttle input for almost 2.5 miles of that slight downwards descent... :-)

I don't have data for anywhere closer than 2 seconds and I don't have enough

2 second data either, it appears to be more efficient, but like I say, I don't have enough data.

I can't say that I've noticed any buffeting in a car, ever; I have not, however, tried to follow anything closer than 2 seconds for a handful of seconds and when doing so...

Coast and burn works really well and thankfully most hazard signs are placed

400 yards from the hazard, with additional 100 yard countdown markers; 400 yards is a workable lift off point for the 1.8t with traffic behind. 600 yards if not. Further under the right conditions...

How possible is coast and burn in a truck? With all that high compression donk and twenty gazillion gears, is it worth trying?

But not in a petrol 406 - lardy buggers, as I recall..