Is this normal fuel consumption normal???

Even when my exhaust was blowing I only maybe lost 20 miles per tank.

Do you know if the engine has been re mapped?

nah the mechanicals and electrics are all as stock as the day it rolled off the showroom floor and the guy I brought it off was a 60 year old family friend that brought it as a little run about but had to sell due to not being eligible to drive anymore so the history is well known and but he never drove it under half a tank of fuel so we don't no when this fuel problem started or if it was like it from new

If you've done all that to it i'd suggest a fuel treatment like redex/stp into a full tank then have a good run with sustained speeds of 55mph+. If its only been used for short runs and "pootled" about before you got it, it could just be clogged up, modern engines need to be worked.
While mine isn't a VVT engine i only ever got about 200 miles or so to a full tank with local driving on stock tyres. Changing back to stock tyres will have made little difference at speed, if anything its worse as you will gear the car up on taller tyres. I drive about 40miles round trip everyday on 195/80 tyres and get almost 200miles to a full tank now its had a fuel treatment through it and a good run recently.

Just an update I've replaced the thermostat and put some cleaner through the system but with no change in fuel consumption, how can I tell of the fuel pressure regulator is playing up and could this be the issue?

250km from a tank of fuel = 155 miles, that really is rubbish :blink:

suggest you setup a camera on the car when it's parked up and catch who's siphoning off a couple of 5 lt jerrys :huh:

I can only get about 190 to 200 miles per tank but the my front hubs are always locked due to a fault within the vacuum system.

Check your hubs are working it may be more than one problem.