Here's some info I posted in a similat thread some time ago, I appreciate that it doesn't fully answer the question because it only talks about getting power per unit fuel burnt rather than covering distance per unit fuel burnt.

In order to rigourously understand how to get the best efficiency from an engine, you need to arm yourself with some dynamometer test results, and plot out a number of graphs. (It is highly unlikely you will be able to get enough data to do this outside a manufacturer's engine lab!)

If on the x axis of the graph, you mark engine speed in rpm

and on the y axis, mark up in BMEP (Brake Mean Effective Pressure - consider it as a measure of load)

On the graph plot contours of constant BSFC (Brake Specific Fuel Consumption - how much power you get per unit mass of fuel burnt)

The graph looks a bit like the skins of a sectioned onion. You get the best power per unit mass of fuel burn in the centre of the "onion".

For petrol engines, the centre of the onion is typically close to the maximum torque speed, and about mid load. This area of optimum economy is quite small for a petrol engine.

For a diesel, the "onion" is more oval, stetched out in the direction of the speed axis - they tend to be less sensitive to manifold tuning effects as they typically run so weak. The centre of the onion is also closer to full load than in the case of the petrol engine.

So labouring along in too high a gear may not be making the best use of your fuel - equally, screaming along the back roads near the red line may also not be conducive to good economy.

In the absence of all of the required data, and the time to plot it all out, biassing your driving around the maximum torque speed of the engine is not a bad place to begin IMO.

I suppose that with a v-tec having two humps in its torque curve, one below the switching point and one above, that for economy one should run nearer to the peak of the lower engine speed torque peak. The rev range near the switching point gives relatively poor torque.

Number_Cruncher

My brother has one, and as others have mentioned it has very useful mid-range shove.

However his has just had a front wheel bearing replaced at only 14k miles and the fuse for the wipers went the other morning leaving him without wash or wipe.

Both of these faults seem quite common given a read of the briskoda forums.

They are quick cars and undoubtedly great fun, but VW reliabilty? My brothers experience leaves me in doubt. I have a 306 TD that I have driven hard for over 5 years (>115k miles). It has yet to require suspension components and it has never let me down..

Raz.

Try asking at www.jeepclub.co.uk
I always found the forum there very helpful.

Much as I love them, the 240s do have a few points of poor design, and the wires-in-the-hinge is one of the stupidest.
Opinions divide between the purists who buy another proper wiring loom and feed it through the hinge, and those like me who have re-routed all the wires down a length of plastic tube and made an inconspicuous loop between the roof lining and the tailgate.
If you have just bypassed the one wire (lights) so far, be prepared for all the others to fail in due course. The wiper will be next!

The tensioners should be changed at the same time as belt as failure will cause the belt to slip or snap. GSF Parts (German, Swedish and French) should have relevent cambelt fitting kit needed.
Also make sure the crank shaft pulley/harmonic balancer is in good condition as there have been reports (and I believe a recall) of the outer part of pulley seperating from inner part and causing fan belt to let go which then tears into cam belt cover with expensive results. If you do remove crankshaft pulley, check locating keyway hasn't worn thus enabling pulley and crankshaft cambelt toothed part to slip out of sync.

There are devices that fit between twin cam toothed wheels to lock them in position but as in common with other PSA engines, a set-screw can be used to fix cams in position. But check with your Haynes manual or similar first!

Andrew