[jambo]

Depends on the fuelling system. Top Gear took a V8 diesel Audi to Edinburgh and back on a tank of fuel a couple of years back. With the modern FI in that if you coasted with your foot off the gas the FI put no fuel into the engine at all, as the engine braking was keeping it turning. A similar system was much criticised on Yamaha's FZ1 when it came out as it led to a hesitation as you went from negative to positive throttle while cornering.

Carbs, of course will always add a little fuel as long as the engine is turning, but using smooth, gentle throttle in the correct gear and not building up speed that you then need to scrub off helps fuel economy.

If all else fails, fit a Sid Squid, annoyingly this makes more difference to fuel economy than anything else I've tried.

Jambo