Hello,
I can comment on A/C performance in the tropics(Kuala Lumpur, Malaysia, ambient around 90-110F,100% humidity)!!!!Car is W115 200 gasoline with Sanden 507, R-12 fill with 11 blade Bosch fan ahead of condensor and 6 blade viscofan on w/p hub.
Car starts at 130F interior air temp, but 5-8 minutes of slow driving drives air temp down to 70F(vent temps at 45F) and any further driving, up to approx. 40mph, and I have interior at 58-65F with vent temps at 35-38F.
In North Carolina, W124 260E struggles in summer to get vent temps down to 45F, interior air around 65-70F. The vacuum element for the recirculate door is shot and I never did get around to replacing it.
I have found that the *modern* aerodynamic cars with heavily sloped front and rear screens let too much heat into the interior, for many years I drove an Opel Manta A with a gigantic shallow rear screen and that car was like an oven, interior air never getting below 70F even with vent temps around 34-36F. I hate the sharply sloped front screens on the cars from the late 1980s to date as the heat soaking is helped along by front and rear screens.
You guys are fortunate in the US that you can have almost *black*(privacy) glass behind the driver, not so here. So I have an black nylon cloth sunscreen permanently fixed to the rear window and I fix a silvered sunscreen to the the front screen when I park.
The R134 systems do not do well here for some reason, taking much longer to pull down interior temps from a heat soak condition, a W210 that I frequently ride in always *roasts* passengers for the first 15 minutes or so.
Just my 0.2 cents, have a good weekend

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Nachi11744