Most efficient speed
I got 26 mpg at 65-75mph (mostly in a 70 mph range) on my 1300 miles trip to Vegas from Seattle, WA through OR, ID UT and AZ.
most times roads were flat but did encounter some serious hills (Dead mans pass in OR). Used cruise control the entire time and wind was either side wind or from the rear (no more than 5-8 mph)
On my 3rd fill up I got 25 mpg. This time my speed was 75-80. Roads were also flat in most cases, 5-8 mph side wind.
most times roads were flat but did encounter some serious hills (Dead mans pass in OR). Used cruise control the entire time and wind was either side wind or from the rear (no more than 5-8 mph)
On my 3rd fill up I got 25 mpg. This time my speed was 75-80. Roads were also flat in most cases, 5-8 mph side wind.
Last edited by JOKER; May 4, 2010 at 03:05 AM.
Joker - I don't think that's what he asked.
Tangerine - I don't have a computer, but remember reading in a car magazine that the most fuel efficient speed on the hwy for most cars is between 50-60 mph. You're right though, a computer would be best suited to figure that out, as who in their right mind could handle driving that speed on the highway for at least a 1/2 tank to do the match!
I too am curious to know this.
Tangerine - I don't have a computer, but remember reading in a car magazine that the most fuel efficient speed on the hwy for most cars is between 50-60 mph. You're right though, a computer would be best suited to figure that out, as who in their right mind could handle driving that speed on the highway for at least a 1/2 tank to do the match!

I too am curious to know this.
"most efficient speed" for a retiree will likely be different than for an average person. a retiree may be able to lope along at 50-55mph and get great fuel economy. however i can't see most folks having the patience to do this. the efficient speed has to be balanced with schedule efficiency and real-world practicality.
even if i'm on vacation, i'll usually push the speed within reason to get where i'm going quicker. why? because i'd rather be relaxing at a lake with a cerveza then driving, no matter how much i enjoy my car.
for instance - i had an 8hr drive a couple years ago. i drove ~70mph (the speed of most of the traffic, i was not passing people excessively) through the mountains and arrived 1.5 hrs ahead of a family member who drove at or just below the speed limit (very annoying person to be behind). on this trip i acheived 30.1mpg, which i consider acceptable in lieu of the time savings.
a bit off-topic, i know. but my 0.02 about fuel economy.
even if i'm on vacation, i'll usually push the speed within reason to get where i'm going quicker. why? because i'd rather be relaxing at a lake with a cerveza then driving, no matter how much i enjoy my car.
for instance - i had an 8hr drive a couple years ago. i drove ~70mph (the speed of most of the traffic, i was not passing people excessively) through the mountains and arrived 1.5 hrs ahead of a family member who drove at or just below the speed limit (very annoying person to be behind). on this trip i acheived 30.1mpg, which i consider acceptable in lieu of the time savings.
a bit off-topic, i know. but my 0.02 about fuel economy.
Last edited by canucklehead; May 4, 2010 at 01:51 PM.
As of late, my navi tells me I've been getting around 32 mpg with cruise control on at 65mph, and the more I raise the speed, the lower my fuel economy drops. I think at 70 I'm getting about 28, 29 mpg now.
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It's not a speed you need to be looking at, it's the RPMs... get a dyno sheet of your car, and where the torque meets the horsepower is where you want the RPMs to be at for the most efficiency. Anywhere the two are close works as well.









