It's beginning to look like D and E are strictly load ratings.

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

Didn't they mandate a minimum 85 mph speed rating for all highway tires years ago? Seems to me it came out back in the early days of radials in the US. After a rash of Firestone tires came apart on cop cars that were chasing good-ole-boys on bias-ply tires. Unfortunately, I think a few cops died in nasty crashes before they wised up that somebody was not doing a good job of making radials. Handled great till the heat built up, then BAM, tire came apart at speed.
To test and rate tires, they run them against a moving drum, at ever increasing speed. Tires have to be able to withstand nnn speed for a sustained period of time to be labled rated for that speed.
This is why I pay the most attention to the second letter in the UTQG rating. It is a measure of a tires resistance to heat buildup. get "A" rated whenever possible. Never less than "B".
I think you will find all tires in this country are rated for at least 85mph. My truck came with a warning to not excede 85 mph, regardless of speedlimits. I expect this was because they did not know what truck tires I would put on it, but they knew all tires were good for 85.

good post