I doubt Sloth would ever be in a position to have a 40 degree day, unlike yourself!

To be fair, we did have at least one dat where the HEVAC was showing 38c outside and I was hooning it through the forest with the AC running and it still never came on high speed.

It is a beast of a fan. I highly doubt it will have a problem keeping the diesel cool on even hotter days.

Hooning = lots of windy roads with heavy acceleration and stop/go. Certainly wasn't just sitting at a constant speed of any sort - I was having fun.

Thanks for the feed back.
I already have a 450W fan, from a BMW 520D car.
If it can cool down the car why not the RR diesel with less power.
I know that the original diesel alternator cannot handle the power needs with AC fully blasting. Hence the need to have a 150A alternator.
Once I get it, will definitely give it a try.