I managed 67MPG: so much for the EPA and EU cycle test ratings...

I do something similar as I approach a hill, letting the car lose mph, except that as I crest the hill and beyond, I will accelerate to at least 10 mph over my target speed and then according to the road conditions (grade), I will either release the gas pedal and stay in the lower part of the EV range (or no show) or keep the accelerator to just around the "O" in ECO. It's unbelievable how long the car will hold a certain speed at a low RPM. My theory is just like pushing a swing, you apply the force as the swing is going down to get the maximum benefit.

 

I have been wanting to say this for a very long time but I bit my tongue........Why do people get all excited about hitting high MPGs for one particular trip?!?!? Who cares!! So you got a wicked tailwind, dry roads, and you were driving at midnight so you hypermiled like crazy!!!! It's not indicative of your overall usage.

For me, only MPG per tank matters. Yearly average would take into account seasonal changes and thus more accurate. Lifetime avg is of course best. It is the best gauge of how the car performs under your foot, in your climate.

 

Because it's FUN?? Maybe not for you but for them??

And because it sets a benchmark that you didn't even know was possible and that encourages you to try to do it again, or something close to it. Which raises your tank mpg and the lifetime mpg for the car.

The first time I hit 100mpg in the Insight on my commute to and from work (35miles each way) I was astonished. That led to getting several whole commuting tanks at >100mpg (10.5 gallons, so >1000 miles, which was also fun).

Ditto for nearly 77mpg (displayed) in the Prius for a summer long trip, here to Boston. Never imagined I might get that. Sure I don't get it all the time, or in winter, but now I know it's possible.

As for the wicked tailwind, I seem to get best results in still air or perhaps a light tailwind. And humid conditions in the low 90's. For some reason.

I agree that the lifetime mpg is what's important, but it helps to enjoy the highs. Because there will be miserably low mpg trips in the rain in the winter into a headwind.

 

You're not affected because you're sensible and practical.

I think some people get excited because they aren't use to the wide swings in fuel efficency performance.
Its like the thrill of being on a rollercoaster... geez -- the Prius can do that? Holy cow!
My goal is to get a lifetime average of 65 mpg (I'm currently at 60mpg over +24000 miles ).
The 3rd generation Prius is capable of +70mpg per tank in warm (>65 F degree) weather without an Electric Block Heater (EBH) so 65 mpg is a very reasonable goal imho.
To achieve an overall 65mpg, my summer fuel efficiency must be +70 mpg to compensate for the winter time mpg drop. (the other option is not to drive the Prius in the winter or to install an EBH to pre warm up the ICE in the winter)

 

The Prius City MPG challenge: The Prius MPG can drop like a rock in city traffic if the Prius is stuck in a traffic jam for any extended period of time. The cause of this fuel efficiency drop is normally due to a deplete HV battery or a significant drop in the ICE coolant temperature drops below 130F after a warmup. In either scenario, the Prius ICE is automatically turn on and run at about. .70gph/1100rpm to recharge the battery or reheat the coolant to about 168F - this will cause the MPG to temporarily drop by about 7 mpg to 12 mpg. The HV battery can become depleted in slow or stop in go traffic when the Prius is driven for an extended time period at speeds under 15 mph using the electric motors. If the Prius gets stuck in the city traffic jam in extreme cold, the Prius stop-idle technolgy will turn off the engine to save gas as the Prius sit there in traffic - but in extreme cold weather (<32F) the coolant temperature will drop steadily until it gets so low ( < 130 F) which will triggers the Prius ICE to rewarm up the coolant (to keep the emission/catalytic converter). If you drive the Prius normally in the city and you encounter a traffic jam longer than 15 minutes either in warm weather or very cold weather - you will likely see one of the above sequence of events .

The work-around: In stop n go traffic or in a traffic jam in warm temperatures, set the Prius to Power Mode and do mini-pulses and glides using the ICE to work up to 10mph instead of using the electric motors. If the Prius is likely to get stuck in stop n go traffic or in a traffic jam in the extreme cold then the Prius air intakes should be blocked ( this is called grill blocking among hypermilers). If the Prius is going to be stuck for longer than 5 minutes in the extreme cold using the defroster or heater continously will burn fuel like crazy - the only way to save fuel turn off the Prius and turn the Prius back on (and warm back up later) when you know you can move forward.

 

I've had my Prius Four since the end of March, and I have about 1700 miles on it. This is my second Prius. I've been averaging around 51 MPG (displayed). Not bad, but not great.

Today I had to drive from a suburb south of Portland to Salem -- a distance of approximately 50 miles. Going down I was in a hurry and drove the freeway at an average speed of around 65 MPH through quite a bit of traffic. Not surprisingly, the MFD showed 48.6 MPG for the trip.

Coming home, I wasn't in a hurry and took two-lane back roads. It was a nice day and there was hardly any traffic. I drove an average speed between 50 and 55 MPH. When I arrived home, the MFD showed 58.4 MPG !

Later I had to run a short errand - maybe 5 miles total during which the car was not turned off. Arriving home, the MFD said 59.8 MPG ! So close to 60 I can almost taste it.

I think the best I ever got in my 2005 Gen II was around 55 MPG, so I'm really happy. Don't know why those two trips were so much better, but I hope I can keep it going.