hi does anyone know how I can improve the mpg on my focus 1.8 tdci

thanks

A basic service is a good start. I bought my car in January, no known service history whatsoever. First job was to replace the air filter for a cheapo from eurocarparts. MPG instantly boosted by 4MPG average. Next job was to get a service done, Kwik Oil service at kwik fit saw a clean bill of oil in there, along with some brake juice and I gained more still. Between that and an ECU reset, I managed to get my overall MPG from about 38 to closer to 50. I now get over 400 miles per tank, closer still to 500, as opposed to the 350 I would get earlier in the year.

On a diesel you could try running it on a better fuel such as shell v power diesel or using an additive such as millers diesel ecomax (I've heard some good things about this one):

http://www.ebay.co.uk/itm/Millers-Diesel-Power-Ecomax-Fuel-cleaner-Additive-treatment-500ml-/151096441073?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item232e0cb8f1

You put one shot in with each tank so there is around 10 tanks worth in this bottle.