Kevin gurgled happily, sounding much like they
were saying:

BTW, many cars may not have a specific sensor. The inlet air
temperature is measured by the fuel injection system, and you could use
that value to drive a low temperature warning.

I dont think that would give a true value ambient value as the venturi
effect will change the temperature(cant remember which way)

Depends on where it is, and on the conditions.

Once the engine & engine bay are good and hot, it'll be warmer than
ambient. Same on a turbocharged engine, if the sensor's looking at the
compressed air, which it'd need to, since it's the temperature as it
reaches the engine that matters.

OTOH, carb icing is a fine practical demonstration of the venturi effect
cooling the air down markedly.

Anyway - most cars don't have an inlet air temp sensor these days - they
measure the mass of the incoming air instead via an air mass meter rather
than air flow meter plus inlet air temp.