Hi there,
Apologies if I'm doing this wrong, I'm new on here.
We've just bought a second hand 2005 mini cooper s automatic convertible 35K miles and I have been driving it to work through London mostly for around an hour twice daily for about 3 weeks and also on longer motorway trips every now and then.
I have been getting about 23mpg average

and I'm pretty concerned this isn't normal, I thought the mpg should be much better. When we bought it, the mpg was at 28 and had been driven on motorways mostly.
Am I doing something wrong? Should I get it looked at? I am trying to accelerate as slowly as possible and not pull off fast in case this makes a difference.
Any help would be really appreciated.