Possible I wouldn't have thought a remap would affect fuel economy unless you're booting everywhere as you got more torque get in the higher gears quicker save fuel stay in the higher gears even,if you feel that may be the issue I'd have the car put back standard and check it out
Funny thing I just realised I had a seized rear calliper,I dont know how long how long it was like it for but I'm convinced since changing it my car is better on diesel now you mentioned it
Daily driving around town budd sometimes enthusiasticly but still would get 49/50 mpg and that's with a re map to roughly 200 bhp and an induction kit driving carefully I get 60 mpg all day my friend