De-tuning a xud for economy?

[Andy annear]

Thanks for responses guys,

Driving is to the beach and back 90% of the time, includes some dual carriageway driving and using A or B roads, avoid towns at all times,

SROWELL I pay 25p/litre for WVO so its alot cheaper than I could get new stuff for,

Tyre pressures are all good, think theyre about 32-34 last time I did them,

Serviced it a few thousand miles ago, havent done fuel filter since but do have a brand new one so will bang that on at weekend when i return her to standard fueling etc,

What kind of MPG's do you guys all get/would expect to get on standard engines if theres any of you left lol

Cheers again!