range question for current FFE owners

[EVA]

Howard - there is one major thing I miss in the Tesla that the FFE has - the Brake Coach. I love that thing. It is a game for me to see if I can get 100% all the time. I'm mad when I get 85%

The brake coach is a circle that shows up after you brake. If you got really good regen during braking, you get a high score. If you brake hard and get little regen, you get a low number.

The reason I love that thing - it makes you a smoother driver. Passengers love that style of braking.

And by the way FFE owners, the Tesla forums are full of people talking about range estimates. WattsUp is 100% correct, nobody has figured out a reliable method for estimating range. Although Tesla does a more transparent job - they have 5, 15, and 30 mile estimates; and instantaneous and average estimates - they really aren't that much better though. I said transparent - maybe it is a more complicated method with 6 different options.

 

[jmueller065]

Its not just the Tesla Forums, even reporters who own Tesla's call it the "Guess-O-Meter":
http://jamiegeek.myevblog.com/2013/10/12/the-guess-o-meter/

 

[EVA]

Nice article JMueller.

The reason the Distance To Empty in an ICE works so well - it is based on miles per gallon as calculated by the car. That number is calculated blindly since the last time you reset the MPG in the car. Most people never reset that number, so the DTE is based on months and months of driving, a massive average. It uses the tank float position to determine how many gallons are left in the tank. They've gotten really good at damping out waves in the tank.

The electrics all seem to use a fairly narrow rolling average to calculate DTE, or range. In the Tesla it is based on the previous 5, 15, or 30 miles. That's a really tiny window to average. I'm betting the FFE isn't too far off on its rolling average - maybe 30 miles.

If you reset the MPG on an ICE, you'll see the DTE go absolutely crazy with weird numbers. After about 10 miles of driving, the number settles down. Eventually DTE gets pretty accurate.

They both work about the same way, it's just we can't let the car calculate a longer range average. An average based on 100 or 200 miles would be way more useful than these instant number.

 

[WattsUp]

The reason the Distance To Empty in an ICE works so well - it is based on miles per gallon as calculated by the car. That number is calculated blindly since the last time you reset the MPG in the car. Most people never reset that number, so the DTE is based on months and months of driving, a massive average.

Hmm, I think a "massive average" would only make range predictions worse (i.e., slow to adapt to changes in driving conditions). I do agree, though, that a long-lived average would make the DTE prediction seem more "stable". But, I think the real reason DTE seems to "work so well" in an ICE is mostly psychological and it really doesn't work any better than in an EV.

Compared to EVs, most ICE vehicles simply have much more range. And, the point at which many ICE drivers think about refueling (e.g., when there are 2-3 gallons left in the tank) is equivalent to the point at which an FFE driver considers their car "fully charged" (and able to go 76 miles, about the same distance an ICE can go on 2-3 gallons). The scale of the problem, and thus the anxiety, is heightened in an EV due to the smaller overall range. In an ICE, with a comparatively large overall range, the DTE estimate can be quite "sloppy" because the buffer of remaining fuel, at the point the driver begins to feel like the tank is "empty", is actually "huge" (for example, 2-3 gallons could take you even perhaps 100 miles in some cars).

In other words: In an EV, we are very sensitive to the accuracy of the range estimate, because we have so little fuel to work with. In an ICE, not so much.

Consider: If the FFE were an ICE it will have no more than a 3-gallon gas tank! Range estimation on 3 gallons worth of fuel (gasoline or electricity) would be just as inaccurate with an ICE or EV. Drive the ICE version of the Focus on the freeway, for example, and it will go about 25% further than driving in the city. If you're doing some city driving after days of freeway driving, the DTE estimate (massively influenced by all the freeway driving you did) would probably be so optimistic about how far you could get in the city to the point of being silly. After all , if you could only ever fill it with 3 gallons at a time, you'd probably be just as sensitive to the inaccuracy of the range estimation as we are in the FFE. (Btw, in the FFE, a 25% difference in range is the difference between 67 and 90 miles. Both reasonable ranges for the FFE, under the right conditions, but entirely based on those conditions.)

With an EV, I think personally that I want a range estimate that adapts quickly. If my driving conditions are stable, I know the estimate can be very useful. If the conditions are not stable, then I understand that producing an accurate estimate is a very difficult problem (and I don't fault the FFE too much for not solving it). And, actually, so long as EV ranges remain relatively limited, I think more intelligent and comprehensive trip planning (that takes elevation changes into account, etc.) would do the most to improve range estimation. Basically, estimating based on known past driving conditions will only get you so far (pun not intended). We need to start taking more of the known future driving conditions into account.

 

[jmueller065]

The reason the Distance To Empty in an ICE works so well - it is based on miles per gallon as calculated by the car. That number is calculated blindly since the last time you reset the MPG in the car. Most people never reset that number, so the DTE is based on months and months of driving, a massive average. It uses the tank float position to determine how many gallons are left in the tank. They've gotten really good at damping out waves in the tank.

I don't think its based on the trip MPG meter that you can reset, at least it isn't in our ICE Focus. In the ICE Focus you can reset each stat of the trip meter individually--its really tedious when getting gas as you have to do 3 resets (Trip Odo, Trip timer, and Trip MPG). The DTE value you don't have to reset..it automatically adjusts itself to the amount of gas in the car.
In addition the DTE value is very stable in the ICE Focus regardless of the past driving style (e.g. if I hop on the freeway and drive for 30-40 miles the DTE value doesn't jump like the FFE's does).
My $0.02: I think this stability is partly due to the fact that the ICE engine's range of efficiency is very narrow (regardless of city or highway driving the MPG really doesn't change that much). On the FFE it changes a lot: at slow speeds the FFE is extremely efficient which drops off precipitously as the speed increases (or the temperatures get cold). Think about it: In the two extremes of max range and min range in the FFE: a nice 72 degree day it will read 100+ miles and a chilly -10 F degree day it will barely read 30 miles (a 3x range).

 

[twscrap]

And by the way FFE owners, the Tesla forums are full of people talking about range estimates. WattsUp is 100% correct, nobody has figured out a reliable method for estimating range.

And nobody ever will - how much lead foot variability you have results in a much bigger impact in an EV than an ICE, and there is no way for the GOM to factor that into its predictions. Eventually the algorithms will get better (assuming you always use the GPS to plot your route), but they will never be able to account for this fact. That's why your brain is your best estimator. You have an idea of how you will drive, so if you know your current SOC and how you plan on driving, you can estimate how far you can go with amazing accuracy.

 

[michael]

I find the cup of energy display to be most useful. It shows me how many Wh/mi I need to maintain to reach my destination. Based on experience I know what I can do, and I can see whether I doing better or worse as time progresses.

 

[WattsUp]

I find the cup of energy display to be most useful. It shows me how many Wh/mi I need to maintain to reach my destination. Based on experience I know what I can do, and I can see whether I doing better or worse as time progresses.

I agree.

And, that's also what the "status" (or "surplus" when navi is engaged) numbers do for you too (in a slightly different way). If the status is positive, you know you're okay. If not, then all you can really do is go slower and/or turn off the HVAC and watch for the status to "go positive" again. But, the estimate adapts relatively quickly to give you timely feedback. (Again, that's why I don't want a "massive average" going on.)

 

[unplugged]

Consider: If the FFE were an ICE it will have no more than a 3-gallon gas tank! Range estimation on 3 gallons worth of fuel (gasoline or electricity) would be just as inaccurate with an ICE or EV.

Exactly!

And as WattsUp stated, there should be an accurate method of determining range by future estimation. For instance, there is no technological excuse for not using the destination, as input into the navigation, to calculate temperature (and even future temperature), elevation rise, and highway speeds, to name but a few variables. All this takes is a bit of innovation. And it really isn't rocket science.

 

[jmueller065]

And as WattsUp stated, there should be an accurate method of determining range by future estimation. For instance, there is no technological excuse for not using the destination, as input into the navigation, to calculate temperature (and even future temperature), elevation rise, and highway speeds, to name but a few variables. All this takes is a bit of innovation. And it really isn't rocket science.

It actually could go a lot further than that: Think of Google Now and/or Apple Siri (although Google Now is a bit ahead). The car could learn your habits, and even record power consumption along frequently used routes, then use that information.
It could have decision making such as:

Its 7am on a weekday, I have all this data for a route to XYZ Corp I think I'll use that to estimate range until the driver goes off that known route

That would be much more accurate than any estimate using navigation features as it would be based on your average performance over a known route.

It would only have to use the map data, etc. when you are traveling down an unknown route.

 

[cta4762]

One of these spring days I want to push my FFE on a drive over a mountain to the next county and back. If I travel clockwise, I'll go up a rather long and steep uphill switchback road and have a gentler trip back. Counter-clockwise I'd have a gentler uphill and down and up and then go down the big, steep hill using L part of the way and some braking. I'm guessing the safer route re: making it to the charge point on my way home is counter-clockwise, but does it make much difference?

 

[lespen]

We are really interested in a 2nd EV. Currently own a Tesla Model S so am fairly familiar with range degradation issues (speed, winter)

Test drove an FFE this past weekend and love the car. But it seems about 20 mile short on range compared to what we need. We were hoping for 80 summer and 60 winter with say 10 mile left when returning home. The FFE wouldn't be used for a fixed commute pattern, thus we want a bit more freedom for some daily errands. The test drive started at 71mi fully charged, driving it fairly gently yielded about a 1 to 1 correspondence to the predicted range.

Looks like its about 60 summer and I guess maybe 40 winter? (Winter months definitely take a bite into the range in our Tesla although it has plenty for the day) if I keep the 10mi buffer?

BTW, I'm in the Pacific Northwest so winter's cold and rain does take a range bite of the Tesla along with some hills. We average around 350Whr/mi on the Tesla during the winter and probably closer to 300 in the summer. I was surprised to see FFE isn't too much lower.

Anyhow, looking for feedback if my range projections are about correct on the FFE.

My winter range was about 50 miles here in Wisconsin (coldest winter since 1979) with the heat set at 65 and seat heater on 3. Yesterday with outside temp at 83 degrees the range on starting was 88 miles

 

[lespen]

I'll be the contrary view relative to the Volt. I much prefer driving our Volt vs. our FFE, but my wife feels the same so I drive the FFE 95% of the time. The software in the Volt is rock solid while the FFE software is by far the worst of any car I've driven (with the exception of other Ford cars with Sync). I've been surprised by how much this one aspect of the car degrades the whole experience for me. As soon as I've got enough saved up, the FFE will be replaced with a Model S.

I've had absolutely no problems with MFT/Sync. Knock on wood

 

[michael]

I"ve got both Volt and FFE, and I find the Ford user interface much easier and more intuitive than the Volt. Volt has the hodge-podge of buttons and touchscreen, and it's hard to navigate between functions without returning to home. FFE has the four corner buttons, can navigate anywhere from anywhere.

On the other hand, Volt has more flexibility to set preferences (except the bloody 110 V charging current which always defaults to 8 A).

I'm quite confortable with the FFE electronics, don't understand why so many people hate it.

 

[unplugged]

I'm quite confortable with the FFE electronics, don't understand why so many people hate it.

I concur.

And, while on the topic of the Volt, one of the reasons I didn't consider the Volt was the tiny Chicklet buttons and the hard and plasticy interior. As Car & Driver says, the Focus Electric is "The Tesla Model S for the rest of us...."

 

[v_traveller]

I"ve got both Volt and FFE, and I find the Ford user interface much easier and more intuitive than the Volt. Volt has the hodge-podge of buttons and touchscreen, and it's hard to navigate between functions without returning to home. FFE has the four corner buttons, can navigate anywhere from anywhere.

On the other hand, Volt has more flexibility to set preferences (except the bloody 110 V charging current which always defaults to 8 A).

I'm quite confortable with the FFE electronics, don't understand why so many people hate it.

Agreed! I think it is superior not only from a controls/navigation perspective, but also from an information display perspective. Of our three EVs , the Volt has the most archaic user display with lots of wasted space, and the MFT has the most advanced, comprehensive, and customizable displays while maintaining readability.

 

[Gigi]

Looks like its about 60 summer and I guess maybe 40 winter? . . . if I keep the 10mi buffer?

We average around 350Whr/mi on the Tesla during the winter and probably closer to 300 in the summer. I was surprised to see FFE isn't too much lower.

Anyhow, looking for feedback if my range projections are about correct on the FFE.

From my experience, I think that your range predictions are low. My wife uses our FFE to commute 53 miles. She regularly returns home at this time of year with 29 miles of range.

We got our FFE on January 22nd of this year. The mean temperature here for 1/22-31 was 28 degrees. For those 10 days, our Wh/mile was 335, which would give a range of 58 miles, which was cutting it close for my wife's commute. February was better at 242 Wh/mile with a mean temperature of 45

Since getting our FFE in January, we have averaged 238 Wh/mile, which would give an average of 82 miles range.

It looks like your requirements for the car are just beyond the car's capabilities, but not by much. How accurate is your estimation of miles needed? If the car is used for running around, is there a possibility of charging at home for an hour or two during the day?

 

[Lithium]

3800 miles into the experience, Feb 2014 Avg 350Wh/mile and 55 miles range. May saw 240Wh/mile with 80-105 predict miles range.
I must say the guessometer is optimistic in the summer and conservative in the winter. how?, I don't know.

The one range factor I didn't have a handle on when I lease was the pit of winter 5-10f type environment. The EPA range of 76 is not useful in guiding buyer about worse case scenarios.
I commute 30 miles and in winter max at 55 with heater on etc, defrost and more. This is the one factor that should drive the buying decision above all else.
H

 

[WattsUp]

The EPA range of 76 is not useful in guiding buyer about worse case scenarios.

Neither are the EPA MPG ratings on ICE vehicles.

 

[jmueller065]

The EPA figures are useful for comparing across vehicles...thats about it: You know that the figures should have been computed the same way for each vehicle. Thus you should be able to look at them and figure out which one is more efficient than the other (the same goes for ICE vehicles).

It isn't really intended for use in worst case scenarios. Another reason why EV buyers need to be educated more (either through their own research, or..LOL..by the dealer) before taking the plunge.