Fuel Consumption

[RussJ]

I'm thinking about changing my Saab convertible for an SL  - 95/97 vintage.
Can anyone give me an idea of real world fuel consumption on mixed fast A roads and dual carriageways for both a 320 and a 500?
I have a 120 miles a day commute so I need to have some idea of what I can expect...
Also, are there any particular problems I should look out for?

 

[Matt Crooke]

There are a few others on here that will be able to help better. but i would imagine the cost of commuting that many miles in a SL 500 would cost more than a days wage in Fuel!!!