The red lines mark the part of the road where you have to be in gear to climb up. So if you go in both directions, then the amount of time you are in gear is only about
Now we figure out the percentage of the trip is spent in gear with throttle pressed down.
It comes to about 28% for one way. But you have to remember you are only going up one hill per direction, so the percentage needs to be taken of *both* ways.
So in this picture we show the direction you are driving and the area marked by green where you have to use gear to go up hill.
Same for this one but now we are going in the other direction.
So that becomes 14%. Now to figure out our MPG for the trip, we divide 14% into 100 and then multiply that number by whatever our MPG was during the "pulse" in gear driving up the hills.
Now the only car I have experience with a mpg readout is the Prius. Most hills the Prius would be able to maintain 20mpg. 100/14 = 7.143. 7.143 X 20 = 143mpg.
Now let's say I was off with my estimates, and it was more like 25% of the time I was in gear. (Remember, 25% total means 50%, or half the time I would have been in gear going in one direction. Average is still 80mpg.
But maybe a more realistic scenario would be an average of 15mpg up the hills and in gear hill climbing at 18% of the time. That's still 83mpg. DiamondLarry, It'd be fun if you could test out my theory. What sort of hills were you driving on?
Not all tanks are created equal, they put whatever bumps they need to in them to get them to fit with the required amount of gas.
Yeah, the gauges have symmetrical displays but don't reflect the actual amount of gas left. If you want to be more accurate, you would need to do a full-to-empty tank where you record the mileage and the gauge position. Then, you use this information to make new gauge marks that reflect the real amount of gas left. Here is a made-up example of what I mean :
Since there is always gas below the Empty line, the yellow line is below that. Since alot of GasSavers fill up the tank to the top, the yellow line is above the Full line. The other lines are positioned based on doing the full-to-empty test.
So there's this back country route to a friend's house. It's all windy and slow with lots of very moderate hills. So the whole time you are either going up a slight grade or coasting down a slight grade. Somewhere in the middle there is somewhat of a "peak." On either side you can glide for like 5 minutes. I've done the run in my mom's Prius a few times and I always got stellar numbers without even trying (60s)
As for my picture, picture the car gliding down that steep hill - how far up the other side do you think it would go before reaching 40mph? 5/8ths way up the hill? At that point, put it in gear and "pulse" until near the top, then pop into neutral again and coast to the top. Turn around and do the same thing again.
EDIT: Let's say the entire distance represented in the pic is 1 mile (so the car is not drawn to scale)
Here we have two gradual hills and one gradual hill and one steep hill. I think the second scenario is best for FE than any other scenario possible. But I haven't tested it so that's just my untested hypothesis. That's because I think the short time driving up the hill will be heavily offset by all that gliding down the gradual slope. The Insight would shine in this scenario.