Hi,
Welcome to EM.
(for info to posters this "Fester" has a 1.8 Litre IDI NA Diesel engine, roughly 55hp - 81lb/ft) - its an older mechanical Diesel pump too.
The "Fester" you have is the original IDI engined version so you seem to be doing really well so far - from your figures you are around 50+mpg (imperial) which seems good to me from this car.
As Piwoslaw has tapped, check out the original mods thread if you feel you are at the limit of what you can get with driving alone.
There aren't a lot of mods available for the motor of this car, the aim from Ford will be long-term life rather than extreme MPG. Ford did a TDDI version which may give you longer gearing with a similar gearbox but they are about as rare as chickens dentures here in the UK. You may also be able to use/get the gearbox from a TD Escort (aka Scrote) or an early (as in late 1990s) Focus - if/when a brit tourist crashes a hire car
. But the cost/benefit of this is probably not working for you.
The key mod for this version of the Fester will be weight reduction I think - remove any seats you don't use regularly, the spare, the rubbish in the boot/trunk and so on. You can remove the spare if you get one of those re-inflate cans.
You are then into aero-mods if you want to get a lot more from this model.
Take care on those roads though, I have driven in p-gal and know about the patchy tarmac.
