What was the official mazda answer too...

[zevans]

If the car is standing still you\'re right, damned if you leave it switched on and damned if you switch it off...

...so don\'t have the car standing still, just drive the last five minutes off boost and temperatures of bits in the engine bay should all even out and everything will cool together - therefore no heat soak. Some argue that forced cooling (eg popping bonnet or getting fans to come on when they wouldn\'t normally) is exactly what causes heat stresses.

Remember it\'s not just your turbo - your brake/clutch circuits and the brakes themselves also have a lot of heat to shed after a good tatering, and if the car isn\'t moving there\'s NOTHING to cool those down evenly = warped discs or broken hub bearings or boiled DOT5.

Mine\'s REALLY unhappy if you come off a motorway and then sit in a queue, so now I cruise in 6th the last mile before a junction as well (and I don\'t even have a turbo to upset things.)

[Brett]

Most people know where there journey is going to end, so other than maybe getting caught in a surprise traffic jam, theres no reason for not allowing time/distance in your journey for everything to drop back to low temperatures

[Zimmy]

Interesting stuff.

Just for the record my American \'95 manual simply says (under Protecting Your Mazda/Turbocharger Information) :
"After driving  at freeway speeds or up a long hill, idle the engine at least 30 seconds to cool the turbo. Don\'t abruptly stop the engine after a hard or long drive."

As for the aircon fan thing, I assume this only works because the fans go on harder than needed to compensate for the extra heat generated by the aircon load on the engine? After all the stock computer will actually cut out the aircon automatically if the engine temp gets too high.

Z

[zevans]

Most people know where there journey is going to end, so other than maybe getting caught in a surprise traffic jam, theres no reason for not allowing time/distance in your journey for everything to drop back to low temperatures

Actually that\'s exactly what finished off the gasket in one of my many VG30DETT engines - came off the M65 onto roundabout which I was expecting to boot round in bottom of 3rd as per usual and then get onto the moors...

...and found traffic on it and on the exit I was using... sure enough, two or three clutch-shuffles later PSSSSSSSSSSSSSSSSSSSSSSSSSHHHHHT  :rolleyes: