Thermostat, why mount a 83°C instead of original 88°C?

[tjr]

Hi,
I'm a fairly DIY guy, new to Fiat (Fiat barchetta -95), and fairly new to this forum. The thermostat needs replacing and after digging the old one out, I found that my shiny new one differed from what was mounted (see pic). After blaming the auto parts store(!), I started googling... It turns out a previous owner had mounted a non-stock thermostat (I have since apologised to the the store). The non-stock opened at 83°C (60602148) instead of original 88°C (60609025). My knee-jerk reaction is/was to revert back to original (needing a new hose), but before doing that, I wanted to ask you all:

Is there any engineering advantage to mounting a non-stock thermostat opening at a lower temperature than what the engine was designed for?

Thanks,
T

 

[vexorg]

It's a common misconception that lower temperature thermostats are a good tuning mod because it keeps the engine cooler.
Usually just means the engine isn't running at it's peak operating point since they are designed to run with the coolant at 90 degrees.
On some cars it also means a bit more fuel goes in since it believes it's not up to temperature yet, so a cheap extra fueling trick.

There is a case for them in very hot countries where the cooling system struggles, but it's not a great agrument since it should be able to cope with the ambient.