Car external temperature sensor location?

"Yes they do", what? Have an air mass meter? I can assure you that my system doesn't - I distinctly recall selling the one off the old system on eBay. And neither do the systems factory fitted to TVR Speed 6 engines. They too work by throttle position & lambda. When you want maximum power, the air mass meter is a choke point you could do without. The reason they're used in mass market engines is that they don't need individual setting up.

Anyway, this is way off topic now, and it seems likely that the manufacturers find it easier to use another sensor (which is why my Range Rover had about 5 engine temperature sensors...) so it was a stupid supposition on my part. :o)

Err, no. Air "mass" meters are horrid things, and you don't want one in the airflow when tuning for maximum power.

Huge gurgled happily, sounding much like they were saying:

The AMM on my car provides virtually no restriction to airflow. Only a small portion of the flow is measured as it passes through a calibrated venturi parallel to the main flow.

Huge gurgled happily, sounding much like they were saying:

"Yes, they do", in a "Yes, those two do have IAT sensors" kinda way.

A couple of unusual and very specialised systems which do doesn't disprove "most don't"

Perhaps you're thinking about the old flap valve type? Modern ones very little if any resistance to airflow.

The air mass meter on my car has about half the cross-sectional area of the air filter or the manifold. I'd say that was offering fairly serious resistance to airflow. Fortunately third party tuners sell properly sized AMMs.

%steve%@malloc.co.uk (Steve Firth) gurgled happily, sounding much like they were saying:

...which just shows it's not an inherent issue with the concept of the AMM...

The inlet tract is always constricted somewhere. Removing that restriction can make the vehicle run worse. If it improves things it's a poor design.

It's as if Harry Weslake had never been born.

You can't make generalisations like that. First you have to define what you mean by "worse".

He did understand inlet tract tuning. You should read up on him.

Not always, in the case of the car I was driving yesterday, with ambient temperatures around 0 deg C and compacted frozen snow and ice on the road, the engine management diagnostics tool I had plugged in was showing a (true) mass air temperature of around 30 deg C.

That's what you get when you have a turbo compressing the air to approximately two atmospheres and a heap of snow blocking up the intercooler duct :)

LOL!