3.9 FXI fuel economy question please.

Young chap at work has a Discovery 3.9 FXI Auto, 1994, LHD Import.

Can anyone please advise of any problems or regular failure items on the engine/Gbox of a model of this type and year, which would adversly affect the fuel consumption?

Could anyone please advise ( preferably from personal experience ) of any modifications, re-chipping, re-mapping, after market additions or suchlike, which could be fitted ( short of conversion to LPG or to manual box ) to improve fuel economy?

We can assume for now, that the vehicle is in good repair and working at optimum at this time.

Thank you. Pete.

Sorry to be rude, but if you are bothered about fuel consumption then perhaps you shouldn't have a V8!!!
Incorrect tyre pressures i.e. soft tyres will hit fuel hard as will binding brakes or a stuck viscous fan coupling, perhaps convert to electric fans.
Obviously the condition of all drive components will have an effect, make sure everything is greased up and correct oils/levels.
Overfilling of oil in engine/gearbox/transferbox/axles will cause frictional drag and will hit your fuel figures as well as running the risk of blowing an oil seal.
My 3.9 was rebuilt at 100,000 miles as the camshaft bearings were shot, funny how the dull knocking noise was that and not big end shells as I first thought. (Blame previous owner)
I run mine on LPG, kits will range from a grand to two and a half thousand. it does almost halve your fuel bill but if you dont do many miles it will be a long time before the kit will pay for itself.
And remember Discos will RUST RUST RUST!!!
Basically, if you got a Land Rover then prepare to open your wallet regularly, anything could go wrong at any time, I have learnt this the hard, expensive way but still love the vehicle.

Hello Boomer and thank you for your input.
The vehicle belongs to young chap at work and I am trying to establish, on his behalf, any regular failure items or reasons, the sort of thing that owners will have come across in the past, which would adversly effect fuel consumption.
Your reply is much appreciated and I will pass the information on.
Thank you, Petel