Brake pedal effect

[PhilH]

I know that when you lift off the throttle pedal, the i3 slows with regenerative braking. My question is: does anyone know whether gently touching the brake pedal actuates the mechanical brakes, or does it just cause more regen, and require a harder shove to actuate the mechanical brakes? It would seem it ought to be the latter, since the slow-down on lifting is much less than acceleration on full throttle.

 

[jadnashuanh]

The car has essentially conventional brakes...you press the pedal, it actuates the brakes. Depending on how hard you end up pressing them, you may still get some regeneration. I've only had mine a couple of days, but see it in regen on those few occasions when I actually needed to use the brakes.

And, while most of the newer ICE BMWs have automatic brake drying, the i3 manual suggests you do that when it is wet out to maximize your braking power, should you need it. It also should help keep rust from forming, which, can eventually require new rotors if they get grabby or end up warping as a result.

 

[davidrshelton]

On a related note, I'm actually interested to see if it's possible to somehow actuate the accelerator in a way that allows the car to actually coast. I had read that one reviewer managed to do it by "feathering" the throttle, but I was unsuccessful. Only shifting the car into Neutral actually created a true coasting effect without the regen kicking in.

David

 

[arlorose]

If you depress the throttle by about an inch, you go into coast mode. I've gotten used to it, and it's really quite pleasant.

 

[jadnashuanh]

The main display in front of the driver shows whether it is using or regenerating power...to coast, you adjust the pedal so it is in that zero, or neutral spot. I haven't driven it enough to see how easy it is (just picked mine up on Monday).

 

[stumbledotcom]

I'm finding it pretty easy to modulate the pedal and hit the coast sweet spot. The cruise control also seems optimized for it. My most efficient drives have involved short stints on the freeway with cruise engaged.

 

[Marti3]

Wonder if my right leg will get tired from extensive periods of coasting as it will have to apply just the right amount of pressure to the pedal? Worried becasue I had an ACL surgely couple of years ago and the leg is no longer as strong as it was...

At least i3's accelerator pedal is floor attached which I found being much better for me than "hanging" pedal.

 

[jadnashuanh]

Coasting is no different than driving under load, which on a long flat road is pretty constant. IF the traffic conditions allow (weather, road, etc.), the adaptive cruise control will trump what you can do manually the vast majority of the time. That doesn't work well if the road is curvy or has lots of deep shadows, which can confuse the camera. In that case, turn the camera off, making it a 'normal' cruise control.

It's kind of a trip having the car speed up and slow down with traffic, and come to a complete stop, then restart on its own. There are times when it seems to adjust quite radically, but I've learned to anticipate them most of the time, and can moderate that manually, if I'm paying attention.

 

[Marti3]

Thanks, I was just looking at the Adaptive Cruise Control in the online handbook and you are right it is more or less similar to a regular long flat road driving. What I am thinking of is that oftentimes it can be more difficult to apply a little presure than "regular" pressure as you need to keep your foot at very specific position. But as you say I can use ACC if I find it exhaustive to the leg. Most likely a "false alarm" that I should not be ringing, but good to know so thanks again.

 

[jadnashuanh]

Understand that personal health issues can complicate things, but in this, a slight error in position isn't catastrophic in your overall energy consumption. ANd, if you run in one of the Eco Pro modes, the response on the throttle is 'dulled' somewhat, making it easier to keep it in that sweet spot, if max economy is really that important. But, the computer will likely do a better job since it is checking much more often than you would, and you can keep your eyes on the road rather than the dashboard!

One thing I miss on the i3 is the HUD of my other BMW for both the speed readout and when using the navigation.

 

[davidrshelton]

Wonder if my right leg will get tired from extensive periods of coasting as it will have to apply just the right amount of pressure to the pedal? Worried becasue I had an ACL surgely couple of years ago and the leg is no longer as strong as it was...

I'm member of "ACL Club" as well (had ACL surgery in 2005 along with cleaning up the medial meniscus; further minor meniscus damage in 2012), so I know what you mean.

I've had my i3-REx for over two weeks now and also made a long-distance trip (183 miles round trip). I can say that the pedal force varies under different conditions, and when you hit the "sweet spot," you don't have to apply much force at all. Of course, this is affected by different modes (ECO PRO or ECO PRO+), what speed limit you assign to them, etc. Also, since the car is great at "one-pedal driving," you don't need to apply force as often using the brake. Overall, I haven't experienced foot fatigue or knee pain as a result of the car.

I've decided that there really is not a true "coast" though there is a point on the accelerator pedal where the force is minimal. True coasting would involve zero foot force being applied, resulting in the car moving by its existing momentum and/or gravity. The only way I've truly achieved that is by setting the dial to Neutral--that's coasting. And I've done that with one of the downhill stretches near my house, where once I achieve around 45-50 mph, I set it to Neutral, let off the pedal and let it cruise downhill.

Whee!

 

[MikeS]

TLA (three letter acronyms) are bad enough when they refer to the car. Now using such TLAs when referring to surgery really is expecting a bit much from the reader :twisted:

 

[i3Alan]

TLA (three letter acronyms) are bad enough when they refer to the car. Now using such TLAs when referring to surgery really is expecting a bit much from the reader :twisted:

The TTP Project specializes in center-recursive TLAs.

 

[davidrshelton]

TLA (three letter acronyms) are bad enough when they refer to the car. Now using such TLAs when referring to surgery really is expecting a bit much from the reader :twisted:

The world is filled with TLAs from all bodies of knowledge. I work in a particularly TLA-heavy line of work (IT), and it's hard for me to keep up.

A handy Google search on "ACL knee surgery" would reveal that ACL refers to the anterior cruciate ligament, one of the ligaments at the back of your knee. However, no one I know ever refers to it as that. Unfortunately, we'll need to stay close to our dictionaries and Google to stay abreast with these abbreviated constructs.

Just be glad that you don't have a partial or full ACL tear.

HTH,
David

P.S. As a bonus, in IT, an ACL can refer to an Access Control List.