kalinka wrote:That was my thinking too, but I just couldn't believe myself that hot gases from FEE could get that far back...but seems it's the only answer though.
For the purposes of illustration, if the exhaust gas emits at a velocity equal with the ground, then it will take 0.02s for said gas to reach the rear of the car (1.5m or so) at 250km/h. 0.02s is not a lot of time to cool down, although its hard to know how the gases disperse and mix with ambient air.
Which is, I guess, the point of those temp stickers. The key insight is not how far back they are, it's the fact that they are above the floor. It may give a crude measure of how much gas is mixing above the floor (rather than underneath) either to verify the design or tune the system. Or, it's just simple due diligence.