D and E are strictly load ratings. Light truck tires do not carry speed ratings. I suppose that a manufacturer could voluntarily label then, but to my knowledge, none do. There are A,B, and C load ratings also, but they're much more rare.

And the "R" in 265/75R-16, is for "Radial".

I do not believe that it is mandatory to give a tire a speed rating, last I checked, there were tires that had none. If the tire does carry a speed rating, it will be in the tire's service description. Like one of the following examples:

205/60HR-15

205/60HR-15 89H

205/60R-15 89H

In these examles, the speed rating is shown in bold, and is "H", good for 130 mph. Note how in the last two examples, the tires load rating is shown by the number "89". Passenger car tires use a number for their load ratings, as opposed to the letters of light truck tires. Don't ask me why it is so, as that I don't know...

MV

the W123 needs H rated tires for some stupid reason