Drlving Techniques Question

[marcustcohn]

How do those that consistently get over 5 m/Kwh do it?
I can drive around my subdivision (25mph) and get that sort of efficiency but in normal traffic (35-55) I am back to 4.4 m/Kwh or thereabouts. I drive mostly in ECO although (previous posts notwithstanding) I am of the belief that all it does is provide a gentle foot on the throttle and to achieve early braking for max regeneration.
What are the secrets?

 

[curtegg]

Minimize the power ball change. If you keep acceleration to 2 power balls or less over 5 is easy-peasy.

BTW: I hate 4 power ball hills :?

 

[LEAFfan]

How do those that consistently get over 5 m/Kwh do it?
I can drive around my subdivision (25mph) and get that sort of efficiency but in normal traffic (35-55) I am back to 4.4 m/Kwh or thereabouts. I drive mostly in ECO although (previous posts notwithstanding) I am of the belief that all it does is provide a gentle foot on the throttle and to achieve early braking for max regeneration.
What are the secrets?

Lately, I've decided that I love to accelerate quickly (to 45mph), so I've been doing that on the city streets and I still am getting 5.0-5.2m/kW h and it's lots of fun! I used to accelerate more slowly and use zero to one bubble (2-5kW). So if you accelerate in ECO with a light pedal, use Cruise C when you can, time your lights, and use 'N' to coast when you're some distance from the traffic lights, you'll definitely increase your m/kW h. However, when you go 55mph, your m/kW h will decrease. I've just started to use the freeways/Interstates and I have been going 60mph with ECO and CC, and so far getting 5.0m/kW h on 20 mile RTs. Also, make sure you're heater isn't on by watching your energy screen. If you set your thermostat to '60', it will only come on (when you use the fan) when your cabin is lower than 60 degrees. Hope this helps.

 

[Volusiano]

First of all, you should be driving between 35-45 mph. Then you pulse and glide as much as you can. Gradually get up to your speed limit, then release the pedal just enough to glide while not using any energy but no go into regen either. There are 3 ways you can monitor your gliding.
1. For coarse monitoring, make sure you only show the neutral bubble and no regen bubble to the left and no acceleration bubble to the right, or
2. Make sure your energy bar on the dashboard displays a full bar, or
3. For the more accurate monitoring, make sure the electric motor energy display on the navigator console is a 0, showing neither regen at the bottom or consumption on the top.

 

[foobert]

Wow, that's a huge variance compared to mine. If I run at 60 MPH (indicated), HVAC totally off, CC on -- I'll be averaging about 4.0 mile/kwh on the dash.

How much of that 20 miles is really spent on the freeway at 60 MPH?

What pressure are you running your tires at?

 

[TomT]

Unless you have found a way to suspend the rules of physics, you can not maintain a given speed and expend no energy. Unless, of course, you happen to have a frictionless vehicle and drive in a vacuum...
The concept of "pulsing" and "gliding" does a disservice to those who do not understand this. It makes no difference how you get to a given speed, or how fast, or from above or below that target speed; you will still use exactly the same amount of energy to maintain that speed once there. Since the bubbles are quite coarse (about 8Kw each), it may appear that you are using no energy but such is not necessarily the case.

First of all, you should be driving between 35-45 mph. Then you pulse and glide as much as you can. Gradually get up to your speed limit, then release the pedal just enough to glide while not using any energy but no go into regen either.

 

[EdmondLeaf]

can you comment/elaborate on that, how often you do that and how this affect efficiency, what about using N downhill?

and use 'N' to coast when you're some distance from the traffic lights, you'll definitely increase your m/kW h.

 

[Caracalover]

It helps to know the road, and where you use the energy you use. Watch the power display screen while someone else drives or video tape it so you don't get distracted while driving. It will show you where you are "wasting" energy. By using N to coast downhill and gain speed, you can improve your average. Sometimes in ECO you may slow down too fast, and then have to use more energy than you regained to get back up to speed. Either use a lighter foot in ECO or try D or N to slow down and obviously don't use the brakes if you can avoid it. The most efficient travel is in no power use, no regen use. This means allowing the kinetic energy to work for you, rather than trying to capitalize on it by regaining that energy through regeneration.

 

[Caracalover]

Unless you have found a way to suspend the rules of physics, you can not maintain a given speed and expend no energy. Unless, of course, you happen to have a frictionless vehicle and drive in a vacuum...
The concept of "pulsing" and "gliding" does a disservice to those who do not understand this. It makes no difference how you get to a given speed, or how fast, or from above or below that target speed; you will still use exactly the same amount of energy to maintain that speed once there. Since the bubbles are quite coarse (about 8Kw each), it may appear that you are using no energy but such is not necessarily the case.

You are right of course, but by not insisting on a given speed and allowing the speed to wander from 35 - 45, you can increase the use of kinetic energy. Why do you think people do not understand this?

 

[TomT]

Theoretical, if you could manipulate the throttle accurately enough to stay at exactly zero power consumed or regenerated, it would make little difference. But since regeneration is nowhere near 100 percent efficient, every time you take your foot all the way off the throttle and regenerate, you are wasting energy. Therefore, the most efficient method (but not necessarily the one that is always practical), is to shift to neutral and time it so you just coast to a stop. If you can safely maintain your speed downhill, it is also the most efficient way downhill. Often such will not be the case though and you might need to use some regeneration to check your speed.

Having said all that, I don't worry about it that much and just drive unless I really need to stretch the range on a given day.

can you comment/elaborate on that, how often you do that and how this affect efficiency, what about using N downhill?

and use 'N' to coast when you're some distance from the traffic lights, you'll definitely increase your m/kW h.

 

[TomT]

I was assuming that a given driver was competent enough to maintain a given speed without wandering all over the speed map. Failing the ability to do that though, they could just use Cruise Control. For many drivers, cruise control will be more efficient than them manually trying to maintain the speed...

You are right of course, but by not insisting on a given speed and allowing the speed to wander from 35 - 45, you can increase the use of kinetic energy. Why do you think people do not understand this?

 

[keydiver]

You are right of course, but by not insisting on a given speed and allowing the speed to wander from 35 - 45, you can increase the use of kinetic energy.

If I recall, there is another thread that agrees with the concept of constant power, vs constant speed, for lowest energy consumption . If traffic allows, not being so rigid as to demand a fixed mph, but allowing your speed to vary slightly with road grade, should improve efficiency, right?

 

[TomT]

Yes, true, but more difficult for many drivers to do in real world conditions...

You are right of course, but by not insisting on a given speed and allowing the speed to wander from 35 - 45, you can increase the use of kinetic energy.

If I recall, there is another thread that agrees with the concept of constant power, vs constant speed, for lowest energy consumption . If traffic allows, not being so rigid as to demand a fixed mph, but allowing your speed to vary slightly with road grade, should improve efficiency, right?

 

[thefortunes]

Yes, true, but more difficult for many drivers to do in real world conditions...

You are right of course, but by not insisting on a given speed and allowing the speed to wander from 35 - 45, you can increase the use of kinetic energy.

If I recall, there is another thread that agrees with the concept of constant power, vs constant speed, for lowest energy consumption . If traffic allows, not being so rigid as to demand a fixed mph, but allowing your speed to vary slightly with road grade, should improve efficiency, right?

I do this on my daily commute in my Prius (actually shift into neutral going down a couple hills - hit 80mph this morning - then enough accelerator to slowly bleed the speed back off going up the next corresponding hill). I see significantly better mileage doing this than allowing the cruise to regen and try to maintain speed on the uphill.

 

[TomT]

It's simply not going to happen during commutes on most L.A. freeways...

I do this on my daily commute in my Prius (actually shift into neutral going down a couple hills - hit 80mph this morning - then enough accelerator to slowly bleed the speed back off going up the next corresponding hill). I see significantly better mileage doing this than allowing the cruise to regen and try to maintain speed on the uphill.

 

[LEAFfan]

Wow, that's a huge variance compared to mine. If I run at 60 MPH (indicated), HVAC totally off, CC on -- I'll be averaging about 4.0 mile/kwh on the dash.
How much of that 20 miles is really spent on the freeway at 60 MPH?
What pressure are you running your tires at?

The whole 20 miles is freeway/Interstate at 60mph! I reset the m/kW h as soon as I left the ramp and reached 60mph. My tire pressure (checked about every two weeks) is 41 psi. Do you use ECO on the freeway? Soon, I'm going to use 'D' and see if there's much difference. Actually, it surprised me that it was such a big difference from Tony's range chart, but I knew his chart was done in 'D' and without Cruise. The temps are going to warm up again soon, and then I'll try the same 20 mile RT (all freeway/Interstates) in 'D'. I'm going to be surprised if it is 5.0 or better. Everyone should know that if you use CC on a relatively flat terrain, that it will give you more miles because it is hard to keep a steady speed with just your foot. However, I've noticed a big difference in m/kW h when the temps are below 70F.

 

[LEAFfan]

can you comment/elaborate on that, how often you do that and how this affect efficiency, what about using N downhill?

and use 'N' to coast when you're some distance from the traffic lights, you'll definitely increase your m/kW h.

If the hill isn't too steep, you will definitely do better in 'N'. Otherwise, on steep hills, you may build up too much speed.
The streets that I drive on are relatively flat (very slight upgrades at times) so I watch the lights and pretty much know how long they've been green so I usually coast in 'N' from a quarter mile away. Remember, you can just throw the shifter into 'R' at 7mph or higher and it will go to 'N'. You can always hold it to the left for a few seconds if you don't want to use the shortcut. I do this for almost every light. Someone commented earlier that the shifter wasn't made for so many shifts, but what they forgot was how many times do you shift it 'twice' to use ECO? I still use ECO to brake if traffic hasn't moved by the time I get there. Just using ECO and 'N' will easily get you over 5.0 on city streets. Now, I'm going 45mph instead of 38, so I'm coasting farther and putting it in 'N' earlier. With my accelerated starts now, and punching it while driving, I'm still getting 5.0-5.2 and having a lot more fun!

 

[keydiver]

On a relatively flat road at a steady 60 mph I doubt you will see any difference in economy between "D" and "ECO". Although I'm certainly not an expert, as I don't even have a Leaf yet, I'm pretty sure that Tony explained that the reason he didn't do the same tests in ECO is because it won't make any difference at a steady speed. ECO only affects the acceleration and regen. You need the same power to maintain a steady speed in D as you do in ECO. Now, if heavy traffic requires frequent braking and acceleration, then ECO should help.

 

[Caracalover]

I was assuming that a given driver was competent enough to maintain a given speed without wandering all over the speed map. Failing the ability to do that though, they could just use Cruise Control. For many drivers, cruise control will be more efficient than them manually trying to maintain the speed...

You are right of course, but by not insisting on a given speed and allowing the speed to wander from 35 - 45, you can increase the use of kinetic energy. Why do you think people do not understand this?

I have found with mountain driving, it is best to lower the speed as the hill gets steeper. If you are using CC then drop the speed 1 MPH every time the power draw exceeds your max power allocation (Around 20KW for me). For a one hour drive you can constantly use 20 KW. If you are using 40KW on an uphill, you are reducing your range or time of driving twice as fast. CC will not care, and if you don't need the range, you shouldn't either. If you do though, watch the power meter and the amount of time you are using the energy you have. You have 20KWH or so before you get to LBW. How you spend it is up to you.

 

[LEAFfan]

On a relatively flat road at a steady 60 mph I doubt you will see any difference in economy between "D" and "ECO". Although I'm certainly not an expert, as I don't even have a Leaf yet, I'm pretty sure that Tony explained that the reason he didn't do the same tests in ECO is because it won't make any difference at a steady speed. ECO only affects the acceleration and regen. You need the same power to maintain a steady speed in D as you do in ECO. Now, if heavy traffic requires frequent braking and acceleration, then ECO should help.

Well, we're going to find out when I drive the same route (20 miles RT @ 60mph) with the same conditions in 'D' with CruiseC. I'm going to be really surprised if I get 5.0 like I did the last time using ECO. Just using CC will give me better m/kW h than trying to hold it to a steady 60mph with my foot. This is true with ICE cars so it should be the same with BEVs. Most people I see driving without CC, speed up then slow down which I then pass them, and then they speed up again, pass me, then slow down, etc...it's crazy and wastes energy!