Based on my most recent thread of "how to get 1000 miles on a tank" https://www.greenhybrid.com/discuss/...tank.4239.html a question was asked about the nature of terrain, so rather than just say "Its a little hilly", like I already did, I decided to take a more scientific approach . . . bust out the GPS and plot it, and let people see for themselves.

This is plotted in "one direction", the uphill route home, but the route is nearly identical in the reverse direction (with small changes accounting for jughandle turns, etc.)

When the weather is warm (above 60 F or so) I can get around 70 mpg round trip based on this profile. With the weather fallen off now I'm able to consistently get just over 60 mpg round trip. I think the main thing to notice is my speed. I only get above 60 mph one time, and that is coasting down the bigger hill. For those of you that are forced to drive at full highway speeds (65 mph and above), 60 mpg is probably out of reach.

 

That is excellent data Josh. Keep up the good work. Pretty flat around here in Boston area but highway speeds are usually 65-70 for the non-hybrid crowd so I usually try to take the side roads at 40-45mph to help FE.

 

What software/hardware did you use to produce that great graph???

 

I don't understand... you drove 10mph most of the time, rarely venturing above 20mph?

EDIT: Haha, I got the elevation and speed graphics mixed up! Phew. But it's still hard to see what speed you're going because of the highly erratic data; you need to average out the data so you get a smoother graph instead of constant dips to 0 and back up.

 

Now that you mention it, there's something improbable about that graph. During the first three stops (I imagine those are traffic lights) the car seems to travel about 1/4 mile at zero speed. If the bottom scale truly represents distance then the intervals of zero speed should have zero length. Also, the spikes of acceleration are awfully steep, as if he went from zero to 50 while covering almost no distance. I would guess that the bottom scale is really time, not distance.

 

Hardware was Delorme Earthmate GPS, bundled with Street Atlas 2004 (now they bundle with Street atlas 2006) running on a laptop.

I did an export of the lat/long/elevation data to GPL file (Delorme proprietory) and used gpl2asc.exe to convert it to an ASCII text file.

Loaded into Excel, ran some formulas and created the graph myself in Excel.

 

Yup . . . there seems to be an error in the way excel plots the X Axis. its trying to normalize the spacing. Good catch. I'll try and fix that. . . so yes, it is "time" . . sort of (The GPS system wasn't logging at "exact" time intervals)

 

ElanC . . . thanks! its been fixed in the first message now. The spikes rightfully don't move when I'm going "0"

I simply changed the graph type from line to scatter, but rest assured, none of the underlying data changed.

 

If I averaged it out, it wouldn't be correct. I initially tried to load a more legible (ie. bigger) version in, but the photo section of greenhybrid only allows for a maximum 640 pixels wide.

You can see where the graph is really "busy", between 15 and 18 miles, there is a ton of stop and go traffic. Bascically, the more dense "green" areas on the graph represent the really hateful driving conditions which kill FE.