Mpg

[rootsnall]

As said by others diesel is more energy dense than Petrol. Also the way a diesel works is different to petrol.

Diesel burns where as petrol explodes. Diesel heats the air in the cylinder as its burns causing it to expand where as petrol explodes using the air up in the explosion but also causing the resulting gases to expand.

On a car becuase the fuel air mixture remains pretty constant in that at low power the car uses a throttle to stop as much air coming into the engine i.e. half power you are not getting a full 2l of air into your 2l engine each rotation.

You may get 1l of air in and use half as much petrol.

In a diesel there is no such distinction. The engine takes a full gulp of air each rotation and the amount of fuel entered is varied. I.e. at full power lots of diesel and at low power not as much.

Means a more efficient process.

Right !

It's all academic now as I'm stuck with my petrol Mondeo for the next decade or so.

[Zorba]

Focus Diesel has to be the best commuting car out there.

Cheap to buy, cheap to run and doesn't attract any attention whatsoever.

It's top of my list to replace my Passat. Mrs Z has one and often gets 50+mpg out of short runs!