These temps are air temps and they serve only as a guideline.

Basically, all MB's, or all German cars for that mater, would like an oil that is xW-40 or xW-50 (there are some thick 0W-30 Euro oils out there). These oils can pretty much go anywhere that is hot like in FL. Plus, these oils can also adequately protect the engine when it goes 130 MPH and plus.

If you insist on XW-50, use a synthetic 15W-50 or 5W-50. Do not use mineral 20W-50.

MB's saying that 0W-40 or 5W-40 has to be used. That is for anywhere and also long drain intervals. For that reason, 10W-30 Mobil 1 was not approved in the newer cars because they do not want 10W-30 to be used in the middle-east or hot Florida, for example. One kind has to listen what manufacture has to say but also know why.

However, synthetic 10W-30 is perfectly fine on your engine in your area as long as you observe the drain interval set in your owner’s manual and do not abuse your engine (redline driving). In your area, you need not worry how high of a temp can xW-40 oil can go because it can go well beyond your hottest temp. A mineral, semi-synthetic, or synthetic 10W-40 or the HDEO 15W-40 should also serve you well (probably better). There are literally thousands of these engines that have gone over 200,000 miles that have never used 0W-40 or 5W-40, although these are superior oils.