How best to drive a plug-in hybrid? Seeking advice.
I’ve gone from a 20 year old 4Runner to a 3 year old Pacifica plug-in hybrid and it has changed many of my driving habits.
For my job I have a lot of deliveries in the neighborhoods of hilly San Francisco and I am curious about strategies I should use to increase the efficiency of battery driving and regenerative braking.
After a month of driving I can’t tell yet if I do better staying on flats or using the energy of the hills. And this thing is so damn heavy! 5000 lbs! (2200kg)
I’m finding that I touch the gas pedal far less and lean on the brake pedal far more, especially after realizing using the brakes won’t necessarily wear them down. But what techniques can I use to make sure I am regenerating instead of using the friction brakes?
Any other general advice about making this switch would also be appreciated. Thanks!
It's always going to be more efficient to stay on flats than to take hills as the energy expenses to climb that elevation (which you'll have to do eventually) will always be much more than any energy you get back via regenerative braking. I'm not familiar with your car model, but the way regenerative brakes normally work is that a light press on the pedal activates them, and a heavier press activates friction brakes to make sure you stop right away. If this is the case, you should brake lighter and earlier for things like stop signs and stop lights, this is actually good practice for any car and will increase the life of your brakes as well as your fuel efficiency, and is also a safer way to drive.
Every time you push a pedal it costs you money.
If you brake hard, it means you also wasted your money from the gas pedal.
In traffic, its exponentially cheaper to coast along at 15 mph for 5 miles than to play stop/go between 0 and 45 for 5 miles.
Automatic-adjusting speed limits are fantastic for that reason. I find that if it's dropped to 35mph or lower, you should drive 5mph below that and you'll avoid most of the accellerate/brake hell that is highway rush-hour traffic.
Plus there's nothing more satisfying than puttering by someone at 15mph who just zoomed past you at 45mph because they're trying to weave their way past traffic.
A small note to add: Most hybrids and EVs activate a portion of regen braking with no pedal input to replicate the feel of engine braking. On some vehicles (like my electric motorcycle) this is configurable. If you want the best possible efficiency and the regen braking is configurable, then you should remove the engine braking analog and coast whenever possible, only activating regen by braking when you need to slow down. It's possible to float the accelerator at the right level to maintain a neutral coast, but it'll be more reliable to just disable accelerator-up regen altogether.
From what I understand, automatic regenerative braking is actually an innate feature of the motors. Every electric motor is a generator when you apply force to spin the shaft. The controller they use on those motors does some sort of magic to mitigate the effect, which I haven't personally looked up.
I hadn't thought about it that way, but you're right. I wonder if 'coasting' in this way is actually delivering a small amount of energy to the motor to neutralize its natural tenedency to generate power and slow down the car.
As far as I know, the magic is that the 'magnet' side of the motor is not a permanent magnet, but an electric one. If you leave it dormant, the rotor and stator are basically decoupled. And depending on whether you phaseshift one electromagnet ahead or behind the other, you determine which side drives the other - I.e. braking or accelerating. The technical term for this is "separately excited", as opposed to a plain magnet which is permanently excited.
Not an electrical engineer, so I might be wrong.
Slow accelleration and breaking is going to be more efficient for pretty much any vehicle.
As was already mentioned, you'll want to make good use of the regenerative breaking. I'm not sure how common this feature is on hybrids, but there may be a mode that will engage the regen whenever you release the accelerator pedal, which is great for city driving with lots of stops and starts. It's less ideal for highway or rural traveling where you won't want to brake unnecessarily.
You'll want to brake as much as you can entirely from the regenerative braking system and avoid the mechanical brakes since they turn all of that energy directly into heat instead of storing it for later. Regen braking is not going to be as strong as the mechanical brakes, as I'm sure you are already aware of, which is one of the major reasons why you'll want to stop slowly.
I really thought I'd like this idea but in practice it really doesn't work for me. I almost always have my throttle-up-regen turned off, unless I'm going down a big hill and don't want to apply the brakes manually.
In stop start traffic I prefer to try to apply just the right amount of acceleration that I don't need to use the brakes at all. Which I am quite good at these days.
Regeneration is great but it's not as efficient as simply not braking in the first place. Without engine braking (or artificial engine-like braking on throttle lift) it's surprising how far a car can roll with only a little power applied at the start. Of course you have to be careful not to be dangerous or annoying for other road users, but even so.
This is interesting. As someone who drives a manual car, one of the things I've most been dreading about the inevitable change to an electric vehicle is the loss of the ability to engine brake. I had thought that the 'one pedal' driving mode would be a similar behaviour that I could get used to, but reading your comment I realise that I usually only want to engine brake where necessary (such as down hills) and otherwise prefer to coast.
Is it easy to switch on the fly, like it is to change gears for more effective engine braking?
My car, a 2017 Hyundai Ioniq, has flappy paddles on the steering wheel to control the level of regeneration. It goes from zero, where the car will happily coast for a pretty long time (I've clocked almost three straight miles without applying any throttle while driving down big hills in Scotland) up to three, which is very aggressive one-pedal style driving for those who like such things.
I often apply regen of levels one or two while coasting down hills where there are speed limits, it is marginally less effort than braking with my foot. Although sometimes I just put the cruise on and let the car manage things, it will prefer regen where possible (as will the brake pedal).
I don't miss engine braking, because it hasn't really gone away, it's just got better. I still have the same behaviour if I want it, and don't if I don't. I also don't miss the wiggly stick thing (I drove manuals until getting an EV because UK don't auto), nor do I miss anything else about an ICE car. Not the having to warm the thing up in winter, not the cost of fuel and maintenance, not the noise or variable torque output, nothing. There is nothing to dread about EVs if you like driving - and I do like driving - electric is just better at the whole thing.
I drove a manual for 15 years before I got an automatic (then a hybrid). Regenerative braking is awesome, it functions more or less the same as engine braking. You just need to stay in the 'charge' lines to avoid engaging the pads.
That said, I still miss how easy you could pop a manual into neutral. Being able to properly coast saves so much gas.
Regenerative breaking sounds like an absolute curse for driving on hilly roads, where you optimally want to coast down hills and use as much of that inertia as possible to get you up the next hill.
Liftoff regeneration basically is mechanically encouraging the obnoxious behavior of bad drivers, where they brake all the way down hills and motor up them.
The most obnoxious road feature of all time is stoplights at the valley between two hills.
The #1 reason hybrids are superior is stop and go with excessive 4 way stops and traffic lights.
You don't have to drive in this mode. Most default to it operating like a standard car.
Coasting at a higher speed regenerates more than the brakes do in my car. I can switch modes with a flick of the stick and tend to drive in glide mode rather than autobrake.
I don't think your worry applies to most people.
I went from a hybrid to a manual. I picked up some driving habits with the hybrid that sort of carried over.
Gentle hills are a good example. I hit the clutch and coast in my manual, I used to just take my foot off the gas in the hybrid. Either way I'm saving gas, something I was completely oblivious to in the car I had before that.
Having driven an EV, I've found this to be not true. I'd just enable max regenerative braking and then drive with a bit of a lead foot. If you think of the pedal as a combined brake and accelerator, with the neutral point in the middle, you can drive normally, and regular braking is just a full lift. Emergency braking is the other pedal of course. Rural or highway driving, you'd then just try to find the point along the accelerator that corresponds to the desired speed, and keep your foot there.
I have a Pacifica hybrid, too. One thing I've found (anecdotally) is that the A/C has a big impact on how far the battery goes (and how much auxillary fuel is used). Like someone elsewhere in the thread indicates, the best thing you can do is drive slower, generally.