The forum does have this nifty QUOTE feature, btw...
Quote: “There is no fallacy here. I never said 80 MPH anywhere in my posts. My example was 70+ to 50 MPH”
Heh, and yet you repeated it that slowing must be in your example at least 20mph difference.
I never said it "must" be at least 20 MPH anywhere. It was a random arbitrary example where in most conditions would yield an efficiency increase. But yes, you will have to slow an appreciable amount. Again, 5 MPH isn't going to cut it no matter what you say.
Quote: “Unfortunately the reality of things are that slowing down is just not always the answer to more range.”
That is true. When driving slow enough that the base loads are more of a factor than the energy to overcome wind resistance, then that is true, because it extends the use of A/C, etc. as you pointed out below, but you don’t seem to have a good handle on what those speeds are. At highway speeds like 60 and up, yeah, it’s always the wind resistance as the main factor, and slowing does save energy, even with climate running heavily.
Unless you live somewhere that is completely flat, even at 60+ slowing by 5 MPH is not necessarily going to have a benefit.
Quote: “As some recent evidence, I crossed Fancy Gap four times in the past two weeks (mountain pass in southern VA). It's 7+ miles of steep grade.”
Ah, you’re picking an interesting example here that hides the wind resistance difference. When climbing a steep grade, there is really heavy energy usage to push the weight up the hill, no matter what speed you are going, so the wind resistance DIFFERENCE shows as pretty small, because it’s all swamped by the high energy use at both speeds. These are quite interesting seeing all of the physics factors involved in driving conditions that people usually don’t pay attention to.
I'm pointing out yet another example of where slowing down at highway speeds has no significant impact. Not hiding anything anywhere, as I gave the numbers. I'm pretty sure there is still wind resistance at 78 MPH heading up a mountain, given that I'm still alive, I'm pretty sure there was air there. A mountain may be on the extreme end of things, but even a slight grade will outweigh wind resistance and there is a point at which slowing down is more detrimental to usage. That number is much different in the real world than what you would like to believe in the fantasy land of just slowing down as a cure all.
Quote: “And while the trip meter is cool, it's never correct and almost always adjusts downward when driving normally.”
Hmm, most people I have seen on this forum and the one at TeslaMotors have found it to be really accurate. I again kind of wonder what you consider “driving normally”.
It is 100% accurate at telling me what it thinks the range will be based on energy usage over the last 30, 15, or 5 miles. It is 0% accurate at actually telling me how far I'm going to be able to actually make it on my current course.
Driving normally = Not caring what car I'm in, ICE, EV, whatever, and driving with the flow of traffic, preferably in the fastest lane of travel, all while being 100% comfortable inside the car regardless of the outside conditions (ie: running the heat or A/C as needed).
Quote: “every other car (ICE, PHEV, EREV, etc) I've ever owned I could run the heat, air conditioning, etc and never have to worry about how much energy was being used or could be saved by dropping my speed 5 MPH. I could always get to where I needed to go without question.”
Ha ha! Yes! That’s because those ICE engines are blowing three fourths of their energy out of the tailpipe and the radiator. When things are very wasteful, overall, smaller levels of wastefulness are somewhat hidden, but when you have something that is capable of being very efficient, small inefficiencies show themselves as more noticeable percentages. Sure, you didn’t worry about getting where you were going, because you can always just pull into a station and fill ‘er up, but that doesn’t mean it wasn’t wasting gas. Even when driving a gas car, I don’t like to go 80 when the speed limit is 80, because the gas mileage just sucks at that speed. I’ll go around 73, because it does help quite a bit, and I noticed that most of the other gas vehicle traffic was going around 75 anyway.
I guess this is always going to be an issue with people who are used to driving gas cars when they try to move to electric. They aren’t used to how they drive having much impact, because the overall wastefulness of the gas engine has hidden it from them. So they just pay to fill the tank, because that’s just the way it is, so they just continue to not know. When seeing that these kinds of driving behaviors matter more in an efficient electric drive train, it’s frustrating to them. It is funny, the mixing of two issues of price versus drive technology. People move from a cheaper gas car to a more expensive electric and then complain that because they paid a lot, it shouldn’t have this issue. But if they had moved from a gas car to a less expensive electric, it would still have exactly the same issue.
Nothing you say above invalidates my point, and you even strengthen it. On average, people don't drive EVs. The average person drives a 5 year old ICE car with 60k+ miles that gets maybe 20 MPG. This is reality. These people get where they have to go, fill up when they need to fill up, and don't care about efficiency. They don't have range anxiety. They drive the speed they want to drive and simply pay for the gas to do it. Simple as that. If they happen to run out of fuel any towing service in the country can cart them out a gallon of gas for $50 and have them on their way. You won't find anyone saying, "Man I need to slow down 5 MPH so I can make it to the next gas station." It just doesn't happen.
So again, nothing you say invalidates my original point: every other car (ICE, PHEV, EREV, etc) I've ever owned I could run the heat, air conditioning, etc and never have to worry about how much energy was being used or could be saved by dropping my speed 5 MPH. I could always get to where I needed to go without question.
Quote: “First, you wont extend range by 5 miles in real world condition by slowing from 78 to 73.”
Not in the first mile, but for a couple hours’ driving, it’ll be more than 5 miles.
We'll have to agree to disagree I suppose. Unfortunately my real world data disagrees with you as well, and I trust my data much more than you.
Quote: “Next, I don't think replacing the 12V battery is really something all that questionable. You mean to tell me if I made a drop in replacement for the Model S's 12V battery that extended range on long trips by up to ~5 miles and only cost a couple hundred bucks that people wouldn't use it?”
That’s not what I mean by questionable. I’m not questioning if people would use it. It’s about whether substituting to a different type of battery would work right in all conditions, given how the Model S is set up to monitor and use and recharge the type of battery it was designed for.
*scratches head*
Quote: “Overall, I really hate it when people assume slowing down is the answer to saving on range. It isn't always and can actually be detrimental in many cases, making it terrible generic advice from people who don't know and explain the caveats.”
But there is a good reason why people say that and it’s applicable. Because the cases where driving slower is detrimental are at very low speeds, like in the 30’s and 40’s. That is when people are driving around town, when they are near a lot more charging opportunities and nearer to home, and are not going for range and long distance, so they’re not talking about or caring about getting extra range. The range discussion comes up when people are traveling longer distances, which is usually on highways, which are higher speeds, where slowing down is always applicable to save energy.
Yet I gave several scenarios where slowing down at highway speeds does NOT save energy... yet you still say "always." This is why people end up stranded in EVs. Bogus advice like "just slow down" that has no qualifiers or real data behind it.
Quote: “So, on topic, I think the idea boils down to this: […]”
Sure, I agree that if such a battery and battery management system could be invented that did those functions in those conditions, then it could benefit.
At least we agree on something. lol.