440 Mpg!!!

[CobraBall]

bennelson,

Thanks for the detailed explanation.

Good job.

CB

[bennelson]

Check my fuel economy chart again.

The last run was 295 eMPG. What a drop!

I was wondering if maybe my brake pedal was sticking!

After thinking about it, that ride was all north of my house, where the speed limits are 45 and 55 MPH.

The air pushes back a LOT harder at 45 than 25 mph!!! Enough that on my electric vehicle, it reduces my "economy" by 25%.

(That's not quite the full story, Peukert's law also is in play here.)

[CobraBall]

"The last run was 295 eMPG. What a drop!"

Living proof of the trusim "Aerodynamic Drag increases as a square of the velocity".

[99metro]

Originally Posted by bennelson

That's your eMPG.

but but but you claimed "MPG" on this thread title. I was mislead. I like the eMPG designation for those of you don't actually USE gasoline and are calculating the conversion.

adios

[TomEV]

Using the calculation, my last charge got me 163.4 eMPG. (226 wh/mile)

One thing I have noticed is that with longer trips, my wh/mile improves. If I only go a mile or so, then recharge, my wh/mile value is just above 300. On 10 mile trips, the value is normally around 260 or so.

This particular charge was exceptionally low, but perhaps I wasn't driving as fast... (fast is a relative term in a Citicar...)

[MetroMPG]

Originally Posted by 99metro

but but but you claimed "MPG" on this thread title. I was mislead. I like the eMPG designation for those of you don't actually USE gasoline and are calculating the conversion.

The fact that we're in the "Fossil Fuel Free" forum might have been a hint it wasn't a thread about gasoline

TomEV: I've noticed the same thing. The farther I go on a charge, the higher my efficiency. It makes sense for a few reasons:

1) Just as with and ICE vehicle, rolling & mechanical resistance decreases somewhat as the tires/bearings/transaxle fluids (if you've got one) warm up, and they'll warm more on a longer trip.

2) But the biggest difference I think has to do with the charger, and measuring energy use at the wall plug. From the point of view of the charger, the most energy efficient charging stage is the bulk phase; the least is the finishing phase (battery resistance rises with voltage, if I recall). If you do short trips and spend proportionately more charging time in the finishing phase, efficiency will apparently decline.

If we could measure energy efficiency of just the vehicle (e.g. from the pack), I'm sure we'd find the swings are much smaller on short vs. long distances traveled compared to readings at the wall.

[bennelson]

I have noticed the same thing in terms of range and efficiency.

Most of my ev rides are about 10 to 15 miles. This seems to put me right into the middle of the battery pack - bulk charging stage.

It also doesn't hurt that my current EV is only 400 lbs. The Metro is going to weigh a little more!

[Arminius]

Originally Posted by bennelson

I'm on a motorcycle! I don't want ANYONE to run into me!

Well, I’m not going to be able to take it away from you if you are conscious!