This is an inclusive term for several conditions involving inflammation of the kidney. Nephritis is the most common cause of blood in the urine of children and young adults but it can occur at any age. If your GP suspects nephritis he will usually refer you to a nephrologist (kidney doctor).
Quick Answer. The average U.S. car weighs in at just 4,000 pounds, which is two tons. This is the average of all mass manufactured vehicles in the United States.
I think those are just the 'payload' weights - for the 1990's car weights, that would be 130,000 lbs. - with a 60 or 70,000 lb. car it would total 200,000 lbs., and that's about right - maybe a little light - for the early years of that decade. Allowable gross weight for freight cars of 263,000 lbs. = 131.5 tons is pretty nearly standard and universal now.