Seat Leon increased fuel consumption and reduction in power.

My long term fuel consumption has recently dropped from 65 mpg to 50 - 52 mpg in the last month. I have had the car 2 + years and can easily get 75 + mpg from it on most long moterway journies. Same journey now I am struggeling to get 65. Through town though there has been a notable drop in mpg. The engine seems to be down on power so needs to be reved slightly higer to get it to accelerate. Once up to speed it seems ok but still not where it used to be. I have not changed my dirving habits, tyre pressures are fine etc. The only things that the car has gone through recently are a service/MOT (3 months ago), timing belt and water pump change (2 months ago) and 2 new rear tyres (1 month ago).

I have also noticed that the DPF reset has not come on for a while (usualy once a month I need to take the car for a long moterway drive to clear the DPF filter). It lets me know because the auto start-stop stops working, the idle increases and when I switch the engine off the fan remains on verry loud. Whenever it has done this I have taken it on the long moterway journey to clear the DPF. Like I say though it has not required a long journey for a while (in the last 2 months) but my proportion of moterway driving has increased recently so perhaps it is going through the DPF cycle while I am on the moterway.