Dick in TN

If you are getting caught in traffic on hot days and the engine is getting hotter than you like wire a high speed fan over ride switch, don't wire an always on, which will just put wear on your fan unnecessarily.

KNS

It sounds like the temps you're running are somewhat normal.

I'll add that when I lived in Phoenix several years ago I had a conversation with the lead mechanic at Stuttgart Southwest about summer temps. He stated that temperatures in the desert southwest (Phoenix, Las Vegas, etc) can really push 964s and 993s to the limit and that they really benefit from additional cooling. He went on to say that on a hot summer day climbing a long incline or mountain pass it wouldn't be unusual to get some pinging/detonation. The problem is the engine is such a noisy beast you'd never hear it.

I heard it myself if I drove close alongside a high wall (driver's side) with the window rolled down, hard acceleration on a hot summer day. I always used 91 octane which was the highest available in PHX. Without that wall next to me I never heard it. I added the Turbo S oil cooler and it made a noticeable drop in oil temps.