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I am new to this forum and have read a few references about speed and MPG loss. What is the relationship?
There's not really a "sweet spot' in the 40-50mpg range.Zaxxon said:Generally, above the 'sweet spot' of 40-50 MPH, going faster costs you mileage, as the wind resistance increases and the engine works harder. Acceleration is the other main drag.
I'm sure someone with more time and better eloquence will come post a much better explanation shortly.![]()
I've only had mine for just over a week, so I could be off-base. I do know that whenever I'm in the 40-50 range and I glance at my MFD, I'm in the 50s-70s in MPG. I could be misremembering this as sustained when it's actually a slight deceleration, though.efusco said:Unfortunately, I can't find/recall where the chart I have is. Anyway, the 'sweet spot' is actually around 25mpg. That said, anything in the sustained 35-45mph range will result in excellent mpg.
He has developed a PC program that does the same and more and should be available soon on his website.mrv said:wind resistance increases by the square of the speed. For most cars, the "tipping point" where fuel economy will get worse as you increase speed is around 55mph.
http://auto.howstuffworks.com/question477.htm
I know that Wayne at http://privatenrg.com/ has a PalmOS program to calculate Prius fuel efficiency based on vehicle speed and wind direction, but I don't have the table of fuel economy figures generated from it handy (nor do I own a Palm).
I agree.efusco said:There's not really a "sweet spot' in the 40-50mpg range.
There was a post at PriusChat...Unfortunately, I can't find/recall where the chart I have is. Anyway, the 'sweet spot' is actually around 25mpg. That said, anything in the sustained 35-45mph range will result in excellent mpg.
Are you sure you're up to speeding up that much? :wink:DanMan32 said:I agree, 80 MPG is extremely optimimistic even for 37 MPH.
I might try driving 37 MPH home sometime when traffic is light and see what I get.
Well, if your implication of me being a grampy driver were true, I'd be getting 80MPG now, wouldn't I? :wink: Then I could report the validity (or invalidity) of that chart.Hep said:Are you sure you're up to speeding up that much? :wink:DanMan32 said:I agree, 80 MPG is extremely optimimistic even for 37 MPH.
I might try driving 37 MPH home sometime when traffic is light and see what I get.
Note change in bold above!MtnTraveler said:I've seen another chart that shows 37 mpH is theoretically the best (at 86°F if I recall). But my experience is much different. I've drivent at 40 mph for a long ways and watched the fancy screen, and I ain't getting ultra high mileage. I've been amazed at reports of 60+ mpg from folks on here. Maybe it's too darn hilly here.
I thought that Hep would have figured it out by now. DanMan32, DanMan32 (bold added). He used to be known as DanMan32mph :lol:DanMan32 said:Well, if your implication of me being a grampy driver were true, I'd be getting 80MPG now, wouldn't I? :wink: Then I could report the validity (or invalidity) of that chart.Hep said:Are you sure you're up to speeding up that much? :wink:DanMan32 said:I agree, 80 MPG is extremely optimimistic even for 37 MPH.
I might try driving 37 MPH home sometime when traffic is light and see what I get.