4 ms·

Lower speeds mean lower air resistance. City fuel economy should be higher than highway if braking energy is recovered at a high enough efficiency.

mrfusion 12y ago
Good point. So really the best milage would be going a constant but lower speed? Like 50MPH?
- SideburnsOfDoom 12y ago
  Seems like it: http://en.wikipedia.org/wiki/Energy-efficient_driving#Maintaining_an_efficient_speed http://en.wikipedia.org/wiki/Energy-efficient_driving#Mainta...
- mikeash 12y ago
  Yep. Don't confuse "highway" for "best". My Prius v is rated at 44 city and 40 highway. If I drive it for extended periods on back roads (i.e. mostly around 55MPH) I can easily get 60+MPG. Optimal speed for any given car will vary depending on the engine, the gearing, and other such things, but typical highway speeds are usually beyond it. This is especially true with hybrids, which can reduce or eliminate a lot of the efficiency losses that normal cars suffer from at lower speeds.
  - blisterpeanuts 12y ago
    That's remarkable. My Prius V (2013) gets about 49 mpg when I drive 55 MPH on smooth, level roads. A couple of times I've hit 50 mpg. Also, I frequent the Prius Chat forum and I've never heard of anyone getting 60+ mpg. Have you modified your vehicle? Is it a plug-in?
    - mikeash 12y ago
      Weird. It's as stock as stock can be. I get 48-50MPG in my normal mix of city/interstate driving. That's on the clock, so de-rate by 5% or so for real MPG as calculated by miles on the odometer divided by gas purchased. Best I saw was 65MPG on the clock over a ~2 hour drive on various country roads coming back to my house, and not flat either (but a pretty minor net elevation change).
- greglindahl 12y ago
  http://cdn.teslarati.com/wp-content/uploads/2014/05/Tesla-Range-vs-Speed.jpg http://cdn.teslarati.com/wp-content/uploads/2014/05/Tesla-Ra... -- this is the diagram for the non-P non-D version. Peaks around 25mph.
- sp332 12y ago
  Most gasoline cars are designed to get best overall efficiency cruising at 55 MPH. That's kind of the crossover point where wind resistance is not crazy high and the engine is still getting good efficiency. So you're burning more gas per minute than you would be in a city, but you're covering a lot more ground per minute as well, so your gas-per-mile is very low.

mrfusion 12y ago

Good point. So really the best milage would be going a constant but lower speed? Like 50MPH?

SideburnsOfDoom 12y ago
Seems like it: http://en.wikipedia.org/wiki/Energy-efficient_driving#Maintaining_an_efficient_speed http://en.wikipedia.org/wiki/Energy-efficient_driving#Mainta...
mikeash 12y ago
Yep. Don't confuse "highway" for "best". My Prius v is rated at 44 city and 40 highway. If I drive it for extended periods on back roads (i.e. mostly around 55MPH) I can easily get 60+MPG. Optimal speed for any given car will vary depending on the engine, the gearing, and other such things, but typical highway speeds are usually beyond it. This is especially true with hybrids, which can reduce or eliminate a lot of the efficiency losses that normal cars suffer from at lower speeds.
- blisterpeanuts 12y ago
  That's remarkable. My Prius V (2013) gets about 49 mpg when I drive 55 MPH on smooth, level roads. A couple of times I've hit 50 mpg. Also, I frequent the Prius Chat forum and I've never heard of anyone getting 60+ mpg. Have you modified your vehicle? Is it a plug-in?
  - mikeash 12y ago
    Weird. It's as stock as stock can be. I get 48-50MPG in my normal mix of city/interstate driving. That's on the clock, so de-rate by 5% or so for real MPG as calculated by miles on the odometer divided by gas purchased. Best I saw was 65MPG on the clock over a ~2 hour drive on various country roads coming back to my house, and not flat either (but a pretty minor net elevation change).
greglindahl 12y ago
http://cdn.teslarati.com/wp-content/uploads/2014/05/Tesla-Range-vs-Speed.jpg http://cdn.teslarati.com/wp-content/uploads/2014/05/Tesla-Ra... -- this is the diagram for the non-P non-D version. Peaks around 25mph.
sp332 12y ago
Most gasoline cars are designed to get best overall efficiency cruising at 55 MPH. That's kind of the crossover point where wind resistance is not crazy high and the engine is still getting good efficiency. So you're burning more gas per minute than you would be in a city, but you're covering a lot more ground per minute as well, so your gas-per-mile is very low.