I've never seem my water temp below 90°C, the oil temp however takes a long time to warm up.Stop-start - AFAIK it doesn't/shouldn't engage if the engine is cold. Summer conditions may keep the engine above a threshold level. In any case, at the moment, my car is at 90C after 1/2 mile. These engines are designed to get to temp. very fast.
I'm not sure if that's science and actual statistical data or just anecdotal - what may be true, is that for a given engine, later models may carry more weight (with more kit fitted). Maybe overall gearing changed? It's really hard to know the facts.....i think i read someone recently saying the later cars aren't as good on fuel as the earlier ones?