Unsure if I need to change thermostat.
Hi, sorry to open another thread about thermostat but I'm a bit unsure. I have a 06 plate gt, 58k miles. I only do short trips, like 3 miles so car doesn't really get upto proper temp. Recently I have noticed a drop in mpg from about 27mpg to 24mpg, although 3mpg isn't much, it is when only doing 27mpg in the first place! Anyway, went for a 20mile round trip today and noticed after the car got to 90 degrees as normal, it dropped back to about 70 degrees and stayed there. My heating was on high to warm car up, not air con, when my interior warmed up and the fans were blowing less, I noticed the temperature slowly creeping back up to about 80-85 degrees. I can't decide if this is normal or not, I'm noticing lately in a morning, it's blowing more out of exhaust, not smoke but steam/water. Is this a sign the stat is on its way out or just because of colder UK weather? Only had car for 6 months and not really had heating on prior to last 2 weeks so don't know what's normal or not! Had a 156 previously and changed the stat but it was more clear cut than this time. Any ideas if I need to change it or not and if so, is it the same procedure as on my old 156? Thanks in advance.