[abba]

I read somewhere that the optimum speed for fuel efficiency is 50 miles per hour. Below this speed, you are burning more fuel per mile than the optimum speed. Above this speed, resistance from the air begins to take effect such that, again, you burn more fuel per mile than the optimum speed.

Fortunately for me, I'm most comfortable at 50 miles per hour.

With all the enhancements to the design of the cars today, is the optimum figure still valid?

[Mario]

That's interesting. I have noticed just base on my observation that I get much, much better mileage when I cruise about 55 as compared to 65 on the highway.

[abba]

Hi Mario, yes that's exactly the point. 65 is way above optimum speed, that's why resistance from the air begins to act on the car to slow it down. You need more fuel per mile to maintain that speed.

[Chaoticdriver]

Great information, thanks. I never thought about the optimum speed. But, as far as gas saving was concerned, my dad used to told me not speed and not to drive too slow either.

[abba]

Maybe you and your Dad had a common understanding of what's fast and what's slow. So, all he needed to remind you was to stay in the middle of those two What's your optimum speed, based on experience?

[Max]

To get to town from where I live, I can go the slow route or the fast route on the interstate. It's the same distance either way. I'm always amazed after going the fast way how far the needle moves down on my gas gauge!

[abba]

Right. It is indeed wise to get to a speed that's optimum -- not too high, or not too low. I presume you travel way above 50pmph at the interstate.

[Dodge Doll]

The speedometer isn't necessarily what I'm watching if I'm trying to be economical as regards gas consumption. While each vehicle is different, I get the best fuel economy if I keep the tachometer below 2400 rpm.

[MyMotor]

I was always taught that the optimum was 55mph, and in fact above sixty you lose 7% fuel efficiency for every 5mph extra you add. Having a lead foot costs you!