I have a 2000 Disco 2. When I got mine 2 years ago it was running 204 on the road and 208-212 at idle. I replaced the factory t stat with a motor rad 180 and had very similar temps to yours. After battling with it for a year I finally decided to replace the motor rad tstat with the LR genuine 180 soft spring t stat. Temps are 187-191 cruising on the highway at 75, idle it settles at 198 with the AC on (aux fan running) and 201 with AC off. If I let it idle long enough it will settle steady at 198.
Since I've had my rig I've replaced the fan and fan clutch with a factory unit, and replaced the rad with a cheap Amazon special unit. Bleeding the cooling system can be tedious, when I got the genuine t stat installed I was getting the reported lower temps on the first bleed. My bleeding procedure was cracking the bleed screw over a period of a week before every cold start and redoing the procedure. My temps stayed the same. I considered doing the inline mod if I couldn't get the temps down, but the factory 180 t stat got them low enough that I'm happy with it. The genuine t stat is also plug and play which and that should be considered. At the end of the day we all want to drive our rigs and not worry about it. I'd get an ultra gauge if you're overly concerned.
Dan
