I have had 3 D2 td5 discoverys, a 2002 manual pre facelift on springs, a 2003 manual face lift on rear air suspension with ace and a 2002 auto on springs.
Without doubt the best for handling, fuel efficiency and reliability was the 2003 manual had the edge in handling over the 2002 manual pre facelift by quite a margin.
For domestic use averaged about 30 mpg locally and up to 34 on long motorway journeys.
Business use towing a 2.5 ton box trailer about 20 mpg.
Bought 2nd hand with 60,000 miles used for 6 years and sold with 150,000 miles and only costs were servicing, tyres brakes etc and rear air suspension bags.
The 2002 pre facelift td5 auto I bought 4 years ago with 46,000 genuine miles and sold last year was a very easy, lazy man's car to drive a real pleasure and whilst the engine was as reliable as any other D2 td5 I have owned, the automatic transmission system was a real pain, nothing serious but niggling electrical faults causing flashing m+s lights and limp mode, very time consuming to diagnose and expensive to fix, final nail in its coffin was losing transmission fluid due to failed pipe clip.
Fuel economy for domestic use was 26 mpg for local driving up to 29 mpg for long motorway journeys Manchester to Geneva.
Now have a freelander 2 sd4 2011 auto coming up to 60,000 miles domestic use only.
Whilst its performance is considerably quicker than a D2 td5, it's handling on A roads is not a patch on the manual, air sprung td5 with ace.