Driving in Low - Poll and Compilation of Threads

[scottf200]

~59.04% of you will like this post about the Honda Fit EV's regen braking
(aside:for a 'compliance' it is getting several great reviews from many pubs as well)

Some nice links in this post as well:
http://www.mynissanleaf.com/viewtopi...210593#p210593

[hull22]

I drive in L all the time, but do find it a bit annoying when on the hilly 2 lane blacktops in Maine because you really feel the deceleration on the down slope. But the regen benefits outweigh the slight discomfort IMHO. When I jump in my 06 Escape Hybrid (with CVT) I use D and forget that I actually have to use the brake pedal to slow down! In the Escape I am using L more often now that I have the Volt to get better regen on long downhill runs under 40MPH. Didn't do that as much pre-Volt.

Are there any regen benefits on those hills if you would not otherwise have to brake on those hills in D? Coasting is more efficient than regen, no?

[Slapshot28]

Are there any regen benefits on those hills if you would not otherwise have to brake on those hills in D? Coasting is more efficient than regen, no?

By feathering the accelerator you can "coast" in any gear (except P and R!), and acheive the same exact effect and the exact same efficiency. It's easy to achieve a nice, controlled "coast" in either D or L. With the Volt, this will consume no energy at all.

Coasting too fast surely is treacherous, so then we need to slow down. The best way to slow down is using 100% regen and 0% friction brakes. That's accomplished the most easily, and efficiently, in L.

[hull22]

By feathering the accelerator you can "coast" in any gear (except P and R!), and acheive the same exact effect and the exact same efficiency. It's easy to achieve a nice, controlled "coast" in either D or L. With the Volt, this will consume no energy at all.

Coasting too fast surely is treacherous, so then we need to slow down. The best way to slow down is using 100% regen and 0% friction brakes. That's accomplished the most easily, and efficiently, in L.

I disagree, it's not the exact effect and efficiency. Take for example, starting at the top of a hill, going down and coming back uphill to a stop at the approximately the same elevation that you started. By coasting in D(or even N), you're letting kinetic energy get you down and part of the way up the hill. You'll have to use a little bit of battery power to make it back up. Going down the hill in L, you're undoubtedly going to lose some of that kinetic energy and convert it into regen energy, and then you're going to need to reuse that regen energy and more battery power to make it back uphill. That regen is undoubtedly less efficient than maintaining kinetic energy. I find coasting at 30-50mph in no way treacherous. I don't find myself really having to slow down using the brake pedal when coasting. If I need to slow down more than coasting to a stop, I'll flip it into L for the stop and back to D.
I don't disagree that if you have to go downhill to a stop, L is better than D because you regen better, I just think it's more efficient to cruise/coast in D than L because regen->accelerating worse than coasting.

[Slapshot28]

I disagree, it's not the exact effect and efficiency. Take for example, starting at the top of a hill, going down and coming back uphill to a stop at the approximately the same elevation that you started. By coasting in D(or even N), you're letting kinetic energy get you down and part of the way up the hill. You'll have to use a little bit of battery power to make it back up. Going down the hill in L, you're undoubtedly going to lose some of that kinetic energy and convert it into regen energy, and then you're going to need to reuse that regen energy and more battery power to make it back uphill. That regen is undoubtedly less efficient than maintaining kinetic energy. I find coasting at 30-50mph in no way treacherous. I don't find myself really having to slow down using the brake pedal when coasting. If I need to slow down more than coasting to a stop, I'll flip it into L for the stop and back to D.
I don't disagree that if you have to go downhill to a stop, L is better than D because you regen better, I just think it's more efficient to cruise/coast in D than L because regen->accelerating worse than coasting.

It's all a matter of your ability to feather the accelerator. Nothing more. In either D or L, by feathering the accelerator, you can exactly emulate coasting, with no energy consumption.

Really, it's about driving preference, not energy consumption.

[hull22]

It's all a matter of your ability to feather the accelerator. Nothing more. In either D or L, by feathering the accelerator, you can exactly emulate coasting, with no energy consumption.

Really, it's about driving preference, not energy consumption.

i agree, it is about driving preference. But most people who driving in L are not likely to feather the accelerator to the point that they are essentially coasting. You'd have press the pedal pretty far down. I guess to me it just doesn't seem natural to step on the accelerator going downhill. I would say that the driving style of L can be less efficient than the driving style of D, at least for the way I drive.

[Slapshot28]

i agree, it is about driving preference. But most people who driving in L are not likely to feather the accelerator to the point that they are essentially coasting. You'd have press the pedal pretty far down. I guess to me it just doesn't seem natural to step on the accelerator going downhill. I would say that the driving style of L can be less efficient than the driving style of D, at least for the way I drive.

No disagreement here either. Personally I am more comfortable feathering than I am coasting.

Disclaimer: my prior car was a six-speed 540i Sport, and most of my others cars have had manual gear-boxes. Driving in neutral or riding the clutch both were no-no's. Feathering the accelerator is second-nature to me.

[Anthony]

Being in the big city (of Vancouver) and doing most of my driving start/stop through the city, I drive in Sport mode and L. I'm averaging 75 km (46 miles) between charges. The worst "mileage" so far has been 62 km jack rabbit starts etc. My best has been 82.5 km (51 miles) before the generator kicked in and I was arriving at home to plug in anyway. I've had my Volt for about 4 weeks and it certainly has exceeded almost all of my expectations. It's been great for extended range (700 km round trip) averaging about 6.1 l/100km or 46 mpg with 2 full charges and a lot of hill climbing and descents (cruise, mountain, and L).

My Volt is the only North American made car I would say I'd buy again.

[Dan Hue]

But most people who driving in L are not likely to feather the accelerator to the point that they are essentially coasting. [...] I would say that the driving style of L can be less efficient than the driving style of D, at least for the way I drive.

Is it OK to go from L to D and back (while moving)?

[tboult]

Is it OK to go from L to D and back (while moving)?

Its not only okay, its fun.. While some people perfer Sport/L I perfer Sport+D->L where I get to downshift when i want to slow down and coasts when I do not want to slow down.

There is no physical gearing, its just a remapping of the pedals, so shift all you want.