Anxiety Disorder Due to Medical Condition. Some diseases and Illnesses cause anxiety, including symptoms that directly mimic anxiety disorders. For example, thyroid conditions can cause sudden and extreme anxiety. Lyme disease can also cause panic attacks and anxiety.
SL: Standard Load; tire for normal usage and loads; XL: eXtra Load; a tire that allows a higher inflation pressure than a Standard Load tire, which increases the tire's maximum load; RF: Reinforcedâfor Euro-metric tires, the term 'reinforced' means the same thing as 'Extra Load' RFT: Run-Flat Tire; Tires designed for vehicles without spare tires.
RE: XL rating for car tires. There is an engineering answer to your question - and then there is the every day good advice type of answer. I'm going to give you the latter, but if you want to talk in depth about the relationship between speed ratings and load ratings, just ask.