Boy you folks covered a lot of ground in a week of postings.
Thanks to Wayne for the mention of my Blog.
First off you need to remember that you have some good info on this Forum. Check out Tire Info Links
if you need to find manufacturer specific info.
RE Tire Load & Inflation charts. The vast majority of tires have identical rating for Max Load at the tires Max inflation. Most tires are covered in the US by the Tire & Rim Association. Occasionally a manufacturer will increase or decrease the load or inflation spec for a specific size & type tire used in a specific application. This adjustment is usually no more than one step in the charts.
RE Max speed rating. If you go look at a passenger tire you will probably see something like P205/70R15 84 H where the 84 is the Load Index and the H is the Speed Symbol associated with the max speec capability of the tire for short duration. Light truck might look like LT205/75R15 LR-C98/95Q a Load Range C tire with the 98/95 being the Load Index for Single/Dual and the Q being the speed symbol associated with a max of 99 mph in short term operation. Truck-Bus Radials might be 255/70R22.5 LR-G 138/134L. Here the L Speed Symbol is associated with a max short term speed of 75 mph. For TBR type tires the Load Index and Speed symbol are otionala so may not be molded on your tire. You will need to look for published data from your tire manufacturer.
NOTE that there may be different ratings from the same manufacturer based on application and specific tire designs so be sure you check the correct data sheet.
I covered these marking topics in a few different posts. I have also covered temperature and Elivation effects.
If you find the info on my blog of value spread the word and please subscribe. I try and give brand neutral information based on 40 years tire design and quality experience.