Freelander Td4 Manual Poor Mpg

Hi folks. I have a 2003 TD4 Manual Freelander on which my MPG seems to be getting worse over the last year. I used to get 32mpg on average now it's down to 28mpg. Even on a recent long trip on which I kept a steady 60 it only returned 36mpg. Now I know I need a Crankcase rebreather filter changed as oil is coming from the dipstick. Will this be the problem or is there anything else I can do? The car has 80000 and is regularly serviced by myself (Thats how I missed the Crankcase rebreather!). Have I missed another part? What do other TD4's get on here. Help much appreciated.

Col

My 04 TD4 commercial does about 33 to 36mpg but thats with 700kg in the back, 2 adults, Falken AT tyres and a Synergy2.

Before the AT's it was about 35 to 38.

Steve