I have just purchased a renault laguna 1.8 ltr which will be ten years old ?

I was getting high 30's MPG from mine.
Has it been serviced recently? Does it drive OK or feel underpowered?
Check the air filter, tyre pressures, brakes are not scuffing.

NOTE- Not related to MPG, but if the timing belt has not been changed, get it done as soon as possible. The belt deteriorates over time regardless of mileage, if it breaks it will wreck the head which will cost more to repair than the car is worth. Take it to a garage that knows Renaults, it's not as straight forward as most other cars, there are no timing marks so the flywheel has to be locked etc.

g.foote
January 2010