Smart Car of America Forum banner

1 - 9 of 9 Posts

·
Registered
Joined
·
312 Posts
Discussion Starter #1
So I have been wondering lately which is better for mileage. Getting up to speed quickly (50% or more power) and then letting off or gradually (under 25% power) getting up to speed? I am thinking it might be better to get there quicker with a short burst of power versus a long slow continuous draw.

Any thoughts or hard data on this?
 

·
Registered
Joined
·
832 Posts
It'll be hard to tell Without an efficiency curve of motor and inverter. But while we're speculating: most inverters typically have peak efficiency near the upper end of their power range. I don't know much about motors.
 

·
Registered
Joined
·
521 Posts
dont know i tried both ways when i first got the car but i cannot stand driving super slow to the speed limit so i just step on it every time and dont really notice that much loss
 

·
Registered
Joined
·
491 Posts
dont know i tried both ways when i first got the car but i cannot stand driving super slow to the speed limit so i just step on it every time and dont really notice that much loss
I have tried both methods. Keeping it under 25% accel gives you a little bit better mileage. However, I always end up with 85% after full charge going home and 60 ~ 65% going back to work to recharge to 100%. In the morning it's cold and I drive more aggressively. I could go to work 2 days without charging, but I prefer to charge everyday.
 

·
Registered
Joined
·
142 Posts
Marc Hanna is the expert, but I've found that if I keep it under 50% at all times, that I get upwards of 75 mi range.

For the examples, I'll use my 10 mi trip home from work.

I've tried to keep it under 25% all the time in one trip and reached 100% Eco within a few miles. 10 miles took 2.1 kWh

I've tried to keep it under 50% all the time in one trip and reach 100% Eco about halfway through the trip. 10 miles took 2.5 kWh

I've tried using the kick down up to the speed limit from stopped at each light or stop sign and destroyed my Eco, getting as low as 16%. 10 miles took 3.8 kWh

It's feasible to consider that at the best you can get nearly 5 mi / kWh, which would mean that your range could be as high as 88 miles. But judging from the 90 mi + Club thread, it's obviously possible to go further.
 

·
Registered
Joined
·
646 Posts
It's feasible to consider that at the best you can get nearly 5 mi / kWh, which would mean that your range could be as high as 88 miles. But judging from the 90 mi + Club thread, it's obviously possible to go further.
I think that is from the additional kWh you generate with the car's regen system, especially in city driving.

The old rule for getting the best mileage with an ICE is to drive like there is an egg under the accelerator pedal that you do not want to break.

I suspect that getting optimal mileage for an EV is probably the same. Not nearly as much fun, but mild and consistent will win out in mileage over jack rabbit starts and quick stops.

A thought occurred to me today while driving my ED, that if everyone out there who drove gas-powered cars was limited to only 3 or 4 gallons of gas in the tank, I bet they would all get WAY better mileage. Having limited range really changes the mentality of driving.
 

·
Registered
Joined
·
184 Posts
If you really care about minimizing use of power vs distance, consider:

resistive heat losses are are proportional to current as is power and acceleration. So, closer to the floor with your foot means more of the battery power converted to heat.

Now, assuming that you get to a higher speed sooner, remember that higher speed means more wind resistance and more power contributing to fighting the wind resistance. So, if you get to the higher speed sooner you will be spending more time paying the cost of the wind resistance than if you stayed at the lower speed longer.

Short story, the slower you go and the longer you take to get to get to that speed, the less it will cost you. Assuming that you have enough patience to do that and that you really, really need to minimize your cost per mile.

A few months ago, I started with thinking that it was really important that my range per charge be close to 80 miles since a full charge costs around $2.00 at $0.11 per kWh. Then, as it started to get cold and I realize that there is no way that I was join to get 80 miles on a charge anyway, I started to think more along the line of what do I need to do in order to make my 44 mile round trip commute and be home with 20% SOC left (53 miles range needed to do that).

From there, all it really means to me is limiting my highway speed and possibly use of heat when I see that my range left plus miles driven is less than 53 miles. Whether it costs me $1.35 per day when it's warm to commute to / from work or $1.60 per day when it's cold is inconsequential in the big scheme of things. When it is warm, I have more choices with regards to how I drive than I do when it is cold.
 

·
Registered
Joined
·
527 Posts
if everyone out there who drove gas-powered cars was limited to only 3 or 4 gallons of gas in the tank, I bet they would all get WAY better mileage. Having limited range really changes the mentality of driving.
I practiced ECO driving techniques when I drove my ICE Ford to work every day.

Now that I have my electric car, I don't care at all to optimize my range, rather, it's all about the enjoyment of the drive, so I crank the heated seats, defrost and rock the stereo. I use "bullfrog power" for my home, so am not at all concerned with my KWH's.

Loving this car!
 

·
Registered
Joined
·
491 Posts
I practiced ECO driving techniques when I drove my ICE Ford to work every day.

Now that I have my electric car, I don't care at all to optimize my range, rather, it's all about the enjoyment of the drive, so I crank the heated seats, defrost and rock the stereo. I use "bullfrog power" for my home, so am not at all concerned with my KWH's.

Loving this car!
That's what I"m talking about!:)
 
1 - 9 of 9 Posts
Top