Roadster Efficiency and Range Excel File

[Yeaw]

Hey everyone,

I am working on a project for school and we are modeling the Roadster to see if a compact CVT could improve overall vehicle efficiency and performance by keeping the motor at the most efficient RPM. The drawback is that a CVT has a mechanical efficiency penalty also. On the Tesla blog, JB posted an efficiency excel file with efficiency and range graphs. I tried to use the wayback machine to get the file, but no luck.
http://www.teslamotors.com/blog/roadster-efficiency-and-range

Does anyone still have a copy of the efficiency excel file they could send me?

Dan

 

[Doug_G]

Is this the one you're talking about?

http://teslaflux.com/Efficiency.xls

 

[Yeaw]

Yes it sure is, thanks for the post!

 

[dpeilow]

I would also like to get the old Excel file but @Doug_G 's link threw a 500 server error. Could you check that please (or if anyone else has it...) ?

 

[Doug_G]

@dpeilow we moved to a new server. I'll fix it.

Edit: Fixed.

 

[dpeilow]

Many thanks.

 

[gregd]

Wow, great resource.

It looks like the Roadster's "Ideal" 248 mile range is based on about a 53 mi/hr speed, dropping to 200 at 65. My current battery only gets to 212 miles on a Range charge, so if the ratio holds, should I only expect a 170 mile range at freeway speeds? (248/200 * 212 = 170) Seems I did better than that when I drove 141 mostly freeway miles to the Fremont factory, arriving with about 70 miles of Ideal range left. Where did the extra 40 miles come from?

I ask because I'm planning a trip about 20 miles farther, and that will be cutting it close if the math holds.

 

[Doug_G]

When you switch to Range mode, more range magically appears. The car hides about 10% at the bottom end when it's in Standard or Performance mode.

 

[gregd]

When you switch to Range mode, more range magically appears. The car hides about 10% at the bottom end when it's in Standard or Performance mode.

Understood, but perhaps I missed something in the graphs... Are they in Standard mode, or Range mode? I assumed Range mode (seems to fit the 248 mile EPA range best). Is the difference a mismatch between EPA and Ideal? I also have assumed Ideal was based on EPA, i.e. a brand new car would Range charge to about 248 miles. No?

 

[supersnoop]

Wow, great resource.

It looks like the Roadster's "Ideal" 248 mile range is based on about a 53 mi/hr speed, dropping to 200 at 65. My current battery only gets to 212 miles on a Range charge, so if the ratio holds, should I only expect a 170 mile range at freeway speeds? (248/200 * 212 = 170) Seems I did better than that when I drove 141 mostly freeway miles to the Fremont factory, arriving with about 70 miles of Ideal range left. Where did the extra 40 miles come from?

I ask because I'm planning a trip about 20 miles farther, and that will be cutting it close if the math holds.

When I make a drive that stretches my range, I set the dash to show estimated miles and reset the trip screen on the VDS. I also set my GPS (or phone) to track the route. That way I can see, especially as I'm getting close to half way, if I have enough estimated miles to make it to my destination without stopping to charge.

Ideal range is based on, if I remember correctly, 230wh per mile. The trip screen also tracks wh/mile, so you can aim for that target.

You mentioned "freeway speeds," but those can vary greatly across the country. I live off a road with an 80 or 85 mph speed limit. The long drives I make are mostly 75mph speed limits. But I have to keep the car right around 62mph to make the 204 mile trip with enough buffer to keep me calm.

Elevation will play a huge role in your ability to make the drive. But even more so, crosswinds seem to affect range. So, always have a plan, keep and eye on progress, know your point-of-no-return, and be prepared to stop and charge if necessary.

 

[dpeilow]

The graphs are based on 55 kWh. So JB Straubel is saying the car had 55 kWh usable.

 

[Doug_G]

The graphs represent the full range of the car, so they are necessarily in Range mode.