For a 15 mile trip the savings is about 3 minutes. Suppose you needed to go 1500 miles, like truckers do all the time. The time saved would be significantly more- about 5 hours.

Positive: 100 %

Answer #2 | 19/12 2013 22:43

You only gain 3min. But you need almost twice the power to combat wind resistance possibly cutting fuel mileage by more than a third (power equals velocity to the third power times the coefficient of drag times the crossectional area times the density of the air). It'll also take the 85mph car over twice the distance to stop than the 65mph car. (It takes roughly 4 times the distance to stop whenever you double your speed). Imagine what that would do in an emergency. Plus you risk a ticket.
Does that make sense?

Answer #1| 19/12 2013 20:31100 %