So, I replaced my thermostat last year, and my car still seems to be on the warm side.

I'm planning on replacing the thermostat as a diagnostic, preventive maintenance, and just for ... giggles.

Anyway, it's happening, so here's the thing. What temp thermostat do I get?

I see 180 and 195 listed. I'm running a black cap. I was told that turbos get higher temp thermostats, but that doesn't make sense to me, UNLESS.... the higher temp gives you higher pressure, gives you more resistance to microboils?

I have checked the temps all over the cooling system with a non-contact temp probe, and basically the cooling system never exceeds 190.

My question is, if a T-stat is rated "180" does that mean full open at 180 or starts to open at 180?
I've been driving around in 108F/30% humidity weather, and I'd like to see cooler temps.

Also, does anyone know of a brand of T-stat that fails in the open position, or is that a scam?

Thanks,
Will
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1990 740 Turbo, on its way to stock specs, maybe beyond