Good afternoon,
It will take another 3 weeks to our holiday, but my brother in Germany warned me from the heat.
I am not too worried. I plan to fill up the water tank (which I always do when we go away), not only for drinking but to be able to refresh.
From the speed I don't plan to drive faster than 130 km/h which should not put too much strain on the engine (even if it is fully loaded). What I will do, is if we stop for a break I will keep the engine running in idle for about a minute or two and not switching it off straight away. This should help to cool down the engine components. My driving teacher told me that many, many, many.... years ago and I read this as a recommendation in 2x German CamperVan magazines (under section tips and tricks of what to do travelling in high temperature).
The fridge will be on for the 3 weeks holidays, but I hope it is designed for that.
I don't believe we have the air conditioning on a lot, but if it gets really to warm of course we will. Recommendation was not to use it too much because it generates extra heat in the engine compartment. This seems to me not logical - not to use the air conditioning if it is to hot?!
Normally I am known to worry a bit too much, but funny enough I am not worried to travel with the California in the heat.
Enjoy your trip and have a wonderful and save journey.
Regards,
Eberhard