(44) Public water system --A system supplying water to a number of connections or individuals, as defined by current rules and regulations of the Texas Commission on Environmental Quality, 30 TAC Chapter 290.
According to studies backed by the department of energy, the average car will be at its advertised MPG at 55 mph. But as the speed increases: - 3% less efficient at 60 mph. - 8% less efficient at 65 mph.
The U.S. Department of Transportation (DOT) set the ratings scale, shown below. 1  But tire makers test their own tires and assign their own speed ratings. On the sidewall of every tire, you'll find one of these speed rating codes: 2  M - Up to 81 mph. 3  N - Up to 87 mph. 4  P - Up to 93 mph. 5  Q - Up to 99 mph. 6  R - Up to 106 mph. 7  S - Up to 112 mph.