I have mk2 focus and noticed mpg dropping on dash says 22.7.

 

Anyway I filled the car to the brim few days ago drove the car did 95 miles round town and refueled. I put in 19.06 litres back to brim. To my working out this works out 22.5 mpg.

 

Mpg seems low. Its had plugs, oil, oil cleaner, air filter last year. Redex.

 

What could be going on

 

Thank you

What engine do you have, and what gearbox?

Automatics are notoriously thirsty especially depending on the gearbox type.

11 hours ago, madman said:

did 95 miles round town

I think that's the key to your problem. Lots of low-gear start-stop driving will seriously hit your mpg.

It's 1.6 ti vct focus manual. When I had Mondeo 1.8 I was getting 27 round town that's bigger car n bigger engine.

Know the dash is not always accurate that's why did fill up to brim.

The ford focus book says 32 urban not a chance in hell getting that.

I had an incidence of a sudden drop in mpg on our old Mk1.5 1.8TDCi. It turned out to be a sticking front brake caliper piston. It was not noticeable on the steering or braking but was causing enough drag to seriously hit the mpg. Yours is probably not that but worth checking.