That is about 26 mpg. But what type of driving was it?
If I drive steady, I get about 35 mpg, or if I drive quickly get about 11-12 mpg!!!

I'd say that 25 mpg is about what I get with a mixture of the 2 driving styles on A/B roads.
Has anybody had a look at the exhaust, as leaks will play havoc with MPG?
Also, the lambda too (although this should throw up a FC in theory??).