We use them all the time on the road(AA) we have a digital fluke one that is fab. Main use is cooling systems seeing when stats open, temp when fans cut in, etc. But as Robin says easy to spot a misfire.
Wheel bearing getting hot!
Binding brakes!
Blocked exhaust!
Hot and cold spots in rad.
Upsetting Apaches on Salisbury plain:blush: (Makes the turrent come round quick!!!!)
Just to name a few.
A very useful peice of kit