[79gmcsierragrande]

Back in the 70s during the gas crunch the “National Speed Limit” was set at 55mph because it was the most fuel efficient higher speed you could go in cars of that time. In the 90s Clinton lifted the National Speed Limit and states were aloud to set them at what ever they wanted. The federal government convinced states to follow the limit by telling them that they would not receive any federal funding for their highways if they did not. Anyways In my truck I can literally watch the gas gage go down at speeds above 55 because the RPMs are so much higher and the 4BBL carb is open full.