I try my best to get the average consumption up but can only manage 44mpg. Could this be a problem with the egr valve or what?

Ive read about people getting 55mpg + easily

I average 35-38 normally. If I'm anal about it I can get low 50s but that's no fun

i have the 75hp version but i find if i drive at 60 to work then the mpg is about 50 but as soon as i get into the town and down to 40, 30 then the mpg drops to about 40mpg

Depends on the sort of mileage and driving you're doing - do these engines have a DPF fitted? If so and you're doing loads of town driving, it can have an adverse affect apparently.