I-Pace efficiency

Discussion in 'I-Pace' started by bwilson4web, Aug 30, 2018.

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  1. bwilson4web

    bwilson4web Well-Known Member Subscriber

    An indication of a problem, we really need to wait on the EPA test numbers.

    Bob Wilson
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  3. gooki

    gooki Well-Known Member

    TopGear were reporting a real world range below 200 miles. I expect EPA range to be slightly above that.
  4. bwilson4web

    bwilson4web Well-Known Member Subscriber

    Is this your source: https://www.topgear.com/car-reviews/jaguar/i-pace/owning

    . . .
    Hypermiling is possible of course, and necessary if you want to get close to that claimed 298-mile range. Here’s the maths: the I-Pace’s spec shows a 90kWh battery, but the car never allows itself all that, for the sake of the cells’ health. So for 298 miles your average consumption has to be less than that total available –84.7kWh divided by that target distance, equals 0.284kWh per mile or (28.4kWh per 100 miles in trip-computer units).

    This is not impossible, but requires some fairly extreme measures such as crawling along at no more than 45mph and denying yourself heating, aircon, stereo, head-up display, lane-assist, wipers and headlights. Real-driving range is probably below 200 miles. This gap is not the fault of the I-Pace. It’s the fault of a new WLTP test, which may be more realistic than the old, but still isn’t realistic enough.
    . . .

    If so, the reviewers are expecting a significantly higher load for the accessories and the "45mph" does not match my experience with EPA data. The Prius Prime has a very efficient, heat pump for heating and cooling. Given the 25 mile EV range, this is a very important range extender. As for slower speeds, yes it helps but they should have done a benchmark run. But I found another.

    Source2: https://www.topgear.com/car-news/electric/top-gears-big-jaguar-i-pace-test-journey-back

    . . .
    But now I was driving late at night on the brilliant Cornish roads in the way a 400bhp Jag invites you to drive. The electricity consumption rocketed. We didn’t make it to Lifton. We found another slow – sorry, ‘fast’ – outlet on the way.
    . . .

    This explains why on cross country trips in our BMW i3-REx or Prius Pime, dynamic cruise control is the way to go. Even with practice, humans are not as smooth, precise, and efficient as automated cruise control.

    . . .
    Finally to our rendezvous with Ollie, again in a hotel car park. There we got the battery to its full state, because that’s the only way to fairly measure the costs of this 320-mile trip. And our energy consumption per mile was well over the WLTP figure because we weren’t hanging around.

    Ready? It was nearly £80. Most days I drive a diesel F-Pace and I could easily do it on £80 of diesel. That calculation added righteous anger to my exhaustion and frustration and stinkiness.

    I threw the Jag’s keys to Ollie, and walked to Watford Junction station. The train back home seemed a very fine mode of transport.
    . . .

    If these had been the previous, Top Gear presenters, I would take schadenfreude. But the current presenters are serious people interested more in facts and data than the clown show Top Gear was before.

    Bob Wilson
    Last edited: Aug 30, 2018
  5. gooki

    gooki Well-Known Member

    Yip, that's the one. The writer went into some more details in the comments. It makes WLTP figures look like a joke if they're 50% greater than real world experience.
  6. David Green

    David Green Well-Known Member

    Bob, that looks pretty similar to the model X, although it looks like in the same battery size the I-Pace might have more range, even before the software is updated... Here is Bjorn's Model X 90D

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  8. Had to write about this yesterday. Efficiency doesn't seem to be the Big Cat's strong suit.

    I'm not sure why, but I don't think it's the aerodynamics. Maybe it's just over-enthusiastic battery management. I suspect it will improve over time, somewhat. Regardless, it's not a fatal flaw, and I don't think it will impinge on sales.
  9. bwilson4web

    bwilson4web Well-Known Member Subscriber

    I agree it won’t affect early adopters who seem impressed by buttons, knobs, and shiny objects. Nothing wrong with that but I prefer Amish plain.

    What poor efficiency does is increase the amount of batteries needed for a given range. It jacks up the price.

    Bob Wilson
  10. David Green

    David Green Well-Known Member

    Domenick, As I posted in the comment section or your story, you did a lot of mixing and matching of data points and really did not make any reasonable conclusion. First you quoted Jack Stewert's Wired article, which if you read the article he said after charging and cleaning up his melted ice cream cone he departed on the trip in 100 degree weather with the A/C blasting, he then says he drove with a heavy foot and a few jackrabbit starts (real world), all on the largest optional 22" wheels. Jack found consumption around 41.6KWh per 100 mi, you quickly compared that to his number in a Smaller, Lighter, RWD sedan at 26KWh per 100m. Did you go back and look at Jack's Model 3 review? No 100 degree weather, no 22" wheels, what do you expect? I would say the 100 degree weather is at least 20% knock on consumption, as the I-Pace has to cool the batteries, and the interior. Did Jack check the tire pressure, for a benchmark, and increase it for max range? Model 3 runs a very rough riding 42 psi to get its max range. Can you see the issue with this comparison?

    You then compared the I-pace to the Model S 100D EPA testing showing 33KWh per 100 mi, This example is lower riding and more aerodynamic, and again the EPA test cycle has no wide open jackrabbit starts (EPA uses a very scientific acceleration ramp that is consistent among all vehicles), No 100 degree temps with the A/C blasting all the time, so again a bogus comparison. You then made a quick reference to the to the Tesla X, which you claim weighs 800Lbs more? Tesla X 90 D weighs 5282lb, and I-pace it 4800 lb, so what did you mean by 800lb difference? and Jack was driving the full spec I-Pace, with 22" wheels, I am going to guess that weighs more then Jag's base number listed in their literature. . You again use the EPA data for the Model X for your comparison, and then you push the conclusion that the I-Pace has poor efficiency... Do you think this was fair data to use to compare, for drawing any real conclusion?

    I used to work on a racing team, and when we dyno test engines, etc, we try to control, or correct all the conditions (temperature, humidity, and even barometric pressure) so we get valuable, and repeatable data. We also do a specific gravity test on the fuel before and after the test to eliminate that as a variable. This is how the EPA does testing too, so I expect to see the I-pace do a bit better then 41.6 KWh per 100 mi, but we will see...
  11. Yes, I used his Model 3 numbers because he said it was over the same basic course.

    No, I did not go back and look at Stewart's Model 3 review, because I can't take an entire day to write a single, short article. Yes, I recognize the official EPA figures will likely be different from this one person's finding. I'm sure that we will publish them and quite probably refer back to this article and talk a bit about the different findings at that time. It should be noted that owners of EVs have found the EPA's numbers quite close to their own real-world driving figures.

    I mentioned the Model S because it's another data point. There are obvious differences between the two, which I pointed out -- the height, weight, and the drag coefficient.

    The Model X P100D weighs 5,531 lbs. The Jaguar's weight is given as 4,702 lbs. The difference is 829 lbs. I understand that there are differences in the weights of different trim levels. This is why I used the phrase "...and weighs as much as 800 lbs more..."

    I, too, hope the Jaguar gets a better rating in official testing than this anecdotal figure.
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  13. interestedinEV

    interestedinEV Well-Known Member

    I will not be surprised if Jaguar engineers can tweak the software and and few other things to improve efficiency a little bit without major redesign. As has been pointed in these forums, Tesla has had all these years to tweak their systems and get the most out of it. This is Jaguar's first try and they still have a little while before end users get their hands on the car. The expectation is that they should be close to 240 miles per full charge (as per their claims on their website). If under actual usage condition, it is less than 200 miles per charge, there will be a major perception issue and it could doom the sales of the I-pace. It could also lead to claims of misleading advertising. If it say, 220 miles per full charge, then there will be more forgiveness and wiggle room. My take is that, while the initial reports seem to point to lower efficiencies, we need to give Jaguar a little time to see if they can do something about it.
    Domenick likes this.
  14. interestedinEV

    interestedinEV Well-Known Member

    The experts in this forum may be able to explain this to me. I looked at 2 Jaguar websites, first says the range is 292 miles on WLTP cycle. https://www.jaguar.com/jaguar-range/i-pace/index.html

    Second which is Jaguar USA site says it is 240 miles based on this disclaimer Figures shown are Manufacturer's driving range estimates. Actual mileage may vary. EPA estimates not available at time of publication. See your local authorized Jaguar Retailer for updated EPA estimates.

    I do not know what WLTP is other than what is written. Why this is difference? Again I am not basher of any company, I am just curious

  15. bwilson4web

    bwilson4web Well-Known Member Subscriber

    In the past, the EPA has swatted down the cheaters. Then there are reports that current policy is to not allow regulations to interfere with profits.

    I have been following the EPA, Argonne Labs, and Idaho Advanced Testing and noticed not one new car has been brought in for independent testing. CARB may still be testing but I don't follow them closely. What bothers me is comparing the Hyundai Insight Blue versus the Toyota Prius ECO in their EPA numbers and FUELLY.COM metrics. The Hyundai user numbers are ~10% lower than EPA while the Toyota numbers are well within the margin of error. Hyundai has already been caught once inflating their efficiency numbers.

    Bob Wilson
  16. interestedinEV

    interestedinEV Well-Known Member

    Domenick, Thanks

    My larger is question is why this big difference between WLTP and Manufacturers estimates. Between 294 miles and 240 miles is almost 20% variation. Is 240 what they expect that the actual user will get.
  17. gooki

    gooki Well-Known Member

  18. gooki

    gooki Well-Known Member

    So real world range for the ipace is approx 165 to 195 miles.

    Looks like WLTP significantly underestimates the effect of aerodynamics on range.
  19. Well, that could be the range number for highway driving at 70 mph, or so. I think the number for most people, who drive a mix of highway and city will be comfortably over 200. Probably 230 miles.

    I'll have a post about good highway driving speeds in a little bit that hopefully clears things up a bit.
  20. interestedinEV

    interestedinEV Well-Known Member

    Watch Jaguar I-Pace Get Driven 232 Miles On A Charge
    But the A/C ws turned off, so the 200 mile range seems reasonable. Bjorn says some people are canceling reservations, though he adds it is a great car. However I am starting to have second thoughts, but will not make any decision till I actually see one.


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  21. interestedinEV

    interestedinEV Well-Known Member

    Jaguar Proves I-Pace Range With Channel Tunnel Drive, The car completed a 229-mile drive between London and Belgium.

    While this is a little different, apparently with 8% charge left and it was in traffic conditions, highways and the channel crossing (drove on the service road, not transported in the rail car)



    Not sure if this was souped up model for this exercise or a regular street version.
  22. bwilson4web

    bwilson4web Well-Known Member Subscriber

    Well it was built at Magna, not a Jaguar factory.

    Bob Wilson

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