EV Questions

i was thinking of it as a range extender, when my ev ran out yesterday, but then, i got more back as the ice was warming. it was pretty sweet!

 

And you aren't seeing what actually happens because you don't really understand it.

Putting energy INTO the battery and then taking it out again later to use is not the most efficient use of the gas engine because of conversion losses going from gas to electric to the wheels........unless it is done at precisely the time that the gas engine needs to run but all of it's output is not needed for propulsion. Then the stored power is USED when the gas engine is running but would need to run outside it's most efficient range to provide the needed power.

Your manual use of the EV button almost surely defeats the computer control which undoubtedly knows more about overall energy efficiency than you do. Forcing the system to be on battery power when going downhill is actually just deceiving yourself and making the numbers look artificially good. This IS a difficult concept for many people to understand but you can't change the laws of physics.

But you don't seem to be able to grasp all of that so I quit. No point is turning a useful discussion into a useless argument.

 

The button is used to prevent the engine from starting in the first place, which would consume more energy during that on/off cycle than the amount of electricity used to pull away from the stoplight and climb the short hill.

The computer is unaware of that opportunity.

 

Because it is NOT an "opportunity".
And how do you propose to know what the computer is "aware" of ??
The real problem here is that you are assuming that you know things that you don't really know.

 

I suggest you do some searches on the SCANGAUGE and TORQUE aftermarket ODB-II devices.

 

The car give us quite a few tools to use, but we have to be willing to learn howto use them. Computers are getting more complex every day it seems, although one example of how the computer in the pri doesn't work well currently is the use of cruise uphill.

I've done that a few times myself

 

Again, the computer doesn't know everything, including traffic, terrain and traffic signals. I can get better mpgs on the highway than cruise control can, because I can adjust my speed for upcoming hills (eg. build up speed for an upcoming hill, then bleed off speed as I'm going up it).

I don't see what you don't understand about john1701a's example. If the long downhill stretch leaving his house is enough to completely recharge the battery from "empty", if he started that trip with the battery at 4-6 bars, the battery would be completely filled to the point of the car needing to rev the engine to burn off excess energy, which is wasteful. The only confusing part I can think of is that the hill must extend far past the length that he uses EV mode uphill for, because you'd need several times that distance/elevation to regenerate the same amount of energy because of losses.

I was initially skeptical of john's claim about the EV button's usefulness, but when he clarified the situation:

I can definitely imagine that the EV button would be useful in the scenario he described.

This isn't the first time I've seen you become argumentative and insulting while repeating the same point and refusing to concede that there are some scenarios in which you might be wrong.

 

You're quoting others, so not saying it's your preference, but anyway:

I'd never think to use EV in a traffic jam, because the car virtually without fail shuts off the engine anyway, in a slow moving situation like that, until the charge becomes depleted.

 

I think you have a lot of this correct, and I agree with you overall.
I'll just point out that the PiP brings another element into the discussion: the ICE cools down during EV driving, perhaps enough to force warm-up routines. IF the number of warm-up routines through the drive are minimized and all else is equal, energy efficiency benefits.

 

Dear EV user. Say you want to get gas and stay cool with the gas station attendant on a hot day? EV
Say you want to silently roll along and look at Chrismas lights with your 90 year old mother and not make a stink? EV
Say you want to run into the store and Leave your Labrador on guard in air conditioning? EV
Shall I go on? Someone said why not, and so they did!


iPhone ?

 

I have never thought of the EV button having any sustained driving purpose. To me it is a very handy mode to use when moving the car in and out of the garage without having the engine firing up for just seconds. It's not a whole lot different than just having parking lights on. That also is a rare situation for many drivers with a few actually really making good use of them.

 

oh sure, in florida.

 

Yep

 

Thanks but no. I bought my car to drive as a transportation device and not as something to play with or as an Engineering learning device.
Even given what you suggest, that doesn't give you real insight into the software algorithms that actually determine what happens and when and why.

 

Not true at all. I absolutely concede that there might be MANY scenarios in which I might be wrong; just that THIS is not one of them.

The electric drive system is most helpful when the gas engine would be taxed and needs help. Coasting downhill is NOT one of those instances because the ICE uses pretty much NO gas when doing that anyway.

 

I could be wrong here but when the car is NOT MOVING or moving very slowly, it will be in EV mode by default unless the battery needs to be charged. I don't see how pushing the button would alter that much if any (maybe the Xmas lights example).

 

Are there any scenarios where you could only force it to drive in EV mode with the EV butting instead of having the car default to EV mode due to low speeds? The only thing that most have been able to agree on is on cold start on warm days.

 

I use EV a lot in the summer when its really hot and kids/wife are with me. I'll pull into a gas station, smack the EV button and let them keep getting cooled with the AC while I fill up.

I also use it some in the driveway shuffeling cars around....

 

I'm pretty sure that this is another case of you fooling yourself because.............
If the car is not moving and indeed even is in PARK, does the engine not go OFF anyway, and stay that way until some condition requires it to run again........which would not be defeated or modified by the operation of the EV button ???

 

It looks like some of the issue here is from not understanding what the EV button actually does.

Using it trades SPEED for POWER.

The usual engine-off driving is faster. When you push the EV button, that top-speed is reduced, but you get more electricity instead.

That exchange make a difference.