C320 CDI???
Also is remapping going to make any difference to fuel economy or is it just hype.
Depends on how you drive and the journey. Firstly these figures are on board dash figures. If its a long motorway run at a constant 70mph the dashbaord figure you should get is about 45mpg. Extremely heavy stop start traffic you'll get 25mpg. Typically I average between 35 and 40mpg on my commute to work which is a mixture of both.
I have noticed the on board figure is a bit optimistic and its about 3mpg higher than actual so reduce the above figures by that amount. I also have Brabus D6 fitted to my car which didn't seem to affect the fuel consumption.
If you are deciding between the c220cdi and C320cdi definitely go for the C320cdi.



