The only thing released to date that's almost as interesting as Tesla's offerings to me.
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Tesla BEV Competition Developments
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The only thing released to date that's almost as interesting as Tesla's offerings to me.
RobStark
Well-Known Member
JRP3
Hyperactive Member
No, those aren't Tesla renderings: This EV Startup's Semi Looks Like Tesla Pickup Truck, But Specs Are Better?
bhtooefr
Active Member
So, something that came up in main over the week was the Taycan and the test procedures used to get such shockingly poor EPA results.
A few comments:
UDDS is the original EPA city test cycle. It's based on sample commuting routes driven in 1969 in Los Angeles, with acceleration limited due to limits of the dynamometer technologies of the time. It's also known as the FTP-72 test cycle. A variation of this, FTP-75, which repeats the first 505 seconds of the UDDS (the cold-start phase of the UDDS, but as a hot-start), is still used today as part of the "5-cycle" EPA energy consumption testing (and still forms the basis of the EPA's figures for city energy consumption, but other tests inform it as well).
CARB uses UDDS for calculating EV range for ZEV credits because they're interested primarily in city energy consumption, and due to their ocean-moderated climate, don't care that much about cold FTP or SC03 results for EV range. Given those constraints, while UDDS range isn't exactly realistic as-is, it's useful for comparison, and therefore useful for ZEV credits.
Now, how the tests are actually done... there's two stages. The first stage is a coastdown test, which is done to EPA procedures, and determines - when combined with the vehicle weight - how much load to put on the dynamometer when the vehicle is being tested. This occurs with the vehicle in neutral - I'm not sure how the EPA accounts for EVs that do not have a true neutral and have significant magnetic drag. I'm also not sure if it matters, because that magnetic drag will always be present. AFAIK, coastdown tests occur outdoors, and are performed in both directions to cancel out slope and wind factors. (Fun fact, this is actually a place that cheating used to occur in Europe - apparently NEDC didn't specify that the coastdown needs to be on the same piece of pavement both ways, and coastdown tracks that are downhill both ways are reported to exist.)
Then, with the known weight of the vehicle and the coastdown coefficients, a road load curve that translates speed to load is created. The dynamometer is programmed to provide this load to the car being tested, and the car is driven indoors, in a climate-controlled environment, on the dynamometer. No wind tunnels are involved here, the vehicle's strapped down to the dyno, and yeah, you wouldn't have wind.
Now, about AMCI. They're an independent testing firm, and as I understand, whatever you pay them to test, they'll test, and report the results. This isn't the first time Volkswagen's used AMCI when EPA energy consumption tests didn't go their way, either... the last time was the 2009 Jetta TDI. EPA mileage was 29 MPG city, 40 MPG highway for DSG automatic, 30 MPG city, 41 MPG highway for the manual. So, Volkswagen got AMCI to test it, and AMCI got 38 MPG city, 44 MPG highway (I believe out of the DSG).
Of course, the Jetta was cheating massively on emissions. Regenerating the lean NOx trap trap on those cars significantly increased fuel consumption, which was reflected on the EPA test cycles - Volkswagen was OK with this because it still improved their averages, but they wanted something better to market, because they knew it would beat that in real world driving. In real world driving, they weren't regenerating the lean NOx trap anywhere near as often, so real world testing produced significantly better fuel consumption, as seen in the AMCI testing.
Now, is the Taycan cheating? I can't see a reason to cheat in that direction. But, the history of Volkswagen immediately reporting AMCI figures alongside the EPA figures is directly tied to Dieselgate...
A few comments:
UDDS is the original EPA city test cycle. It's based on sample commuting routes driven in 1969 in Los Angeles, with acceleration limited due to limits of the dynamometer technologies of the time. It's also known as the FTP-72 test cycle. A variation of this, FTP-75, which repeats the first 505 seconds of the UDDS (the cold-start phase of the UDDS, but as a hot-start), is still used today as part of the "5-cycle" EPA energy consumption testing (and still forms the basis of the EPA's figures for city energy consumption, but other tests inform it as well).
The other test cycles used in the US are HWFET (based on early 1970s midwestern driving, again with acceleration limited, and with relatively low speeds, and the basis of EPA highway energy consumption), Cold FTP (FTP-75 but run at 20 °F and with cabin temperature requirements), SC03 (an air conditioning test cycle run at 95 °F), and US06 (a high-speed test cycle). These test cycles are used to adjust the results of FTP-75 and HWFET to be more realistic, since 2007, and it means that for vehicles certified since 2007, cold and hot weather performance matter. (From 1985 through 2006, FTP-75 and HWFET results were adjusted by 10% and 22% respectively as a flat conversion, to make window stickers somewhat more plausible. Since then, the EPA has a conversion formula that they've applied to old results to make them somewhat comparable to 2007+ results.)
CARB uses UDDS for calculating EV range for ZEV credits because they're interested primarily in city energy consumption, and due to their ocean-moderated climate, don't care that much about cold FTP or SC03 results for EV range. Given those constraints, while UDDS range isn't exactly realistic as-is, it's useful for comparison, and therefore useful for ZEV credits.
Now, how the tests are actually done... there's two stages. The first stage is a coastdown test, which is done to EPA procedures, and determines - when combined with the vehicle weight - how much load to put on the dynamometer when the vehicle is being tested. This occurs with the vehicle in neutral - I'm not sure how the EPA accounts for EVs that do not have a true neutral and have significant magnetic drag. I'm also not sure if it matters, because that magnetic drag will always be present. AFAIK, coastdown tests occur outdoors, and are performed in both directions to cancel out slope and wind factors. (Fun fact, this is actually a place that cheating used to occur in Europe - apparently NEDC didn't specify that the coastdown needs to be on the same piece of pavement both ways, and coastdown tracks that are downhill both ways are reported to exist.)
Then, with the known weight of the vehicle and the coastdown coefficients, a road load curve that translates speed to load is created. The dynamometer is programmed to provide this load to the car being tested, and the car is driven indoors, in a climate-controlled environment, on the dynamometer. No wind tunnels are involved here, the vehicle's strapped down to the dyno, and yeah, you wouldn't have wind.
Now, about AMCI. They're an independent testing firm, and as I understand, whatever you pay them to test, they'll test, and report the results. This isn't the first time Volkswagen's used AMCI when EPA energy consumption tests didn't go their way, either... the last time was the 2009 Jetta TDI. EPA mileage was 29 MPG city, 40 MPG highway for DSG automatic, 30 MPG city, 41 MPG highway for the manual. So, Volkswagen got AMCI to test it, and AMCI got 38 MPG city, 44 MPG highway (I believe out of the DSG).
Of course, the Jetta was cheating massively on emissions. Regenerating the lean NOx trap trap on those cars significantly increased fuel consumption, which was reflected on the EPA test cycles - Volkswagen was OK with this because it still improved their averages, but they wanted something better to market, because they knew it would beat that in real world driving. In real world driving, they weren't regenerating the lean NOx trap anywhere near as often, so real world testing produced significantly better fuel consumption, as seen in the AMCI testing.
Now, is the Taycan cheating? I can't see a reason to cheat in that direction. But, the history of Volkswagen immediately reporting AMCI figures alongside the EPA figures is directly tied to Dieselgate...
willow_hiller
Well-Known Member
An EV cheat device is also arguably easier to pull off than a diesel one.
Teslabjorn inadvertently demonstrated this when he tested a Mercedes EQC with some faulty modules. Basically, the BMS just reports a higher available SOC than what the battery actually contains, until it gets below a certain threshold, after which point the SOC drops off quickly. This sort of non-linear battery reporting can easily fool journalists and any tester who only tests the first X% of the battery and extrapolates the rest. Meanwhile, the EPA test cycle that presumably tests 100%-0% and relies on read-outs from the canbus isn't fooled.
RobStark
Well-Known Member
bhtooefr
Active Member
The EPA test cycle isn't fooled because it starts from fully charged, and runs until the vehicle physically cannot complete the test cycle.
I'd expect an EV cheat to be in the direction of performing better on the EPA test cycle by shutting off things like battery conditioning, reducing HVAC performance, and things like that. I can't think of a reason for an EV to cheat the EPA cycle in ways that make it look worse than the real-world - in the Dieselgate example, less fuel was used by cheating and protecting the emissions hardware, whereas in an EV, more energy would be used when protecting the battery.
I'd expect an EV cheat to be in the direction of performing better on the EPA test cycle by shutting off things like battery conditioning, reducing HVAC performance, and things like that. I can't think of a reason for an EV to cheat the EPA cycle in ways that make it look worse than the real-world - in the Dieselgate example, less fuel was used by cheating and protecting the emissions hardware, whereas in an EV, more energy would be used when protecting the battery.
willow_hiller
Well-Known Member
Maybe VW has learned half a lesson. Don't cheat the government, do cheat your customers.
bhtooefr
Active Member
Having owned a few VWs before, and being a recovered VW fanboy, they know how to do that quite well. Quite well indeed.
(And as much as @neroden complained about Tesla service... nearly everything he's complained about with Tesla service has applied to VW service in the US market, especially on the TDIs. I think about the only thing VW hasn't done is avoid letting you schedule an appointment, and then I've personally had a dealer throw out a ridiculous quote ($1500 for a heater core... but then none of the independent shops wanted to do it either, and I ended up selling the car partially because of that...) to avoid doing a job before, so...)
(And as much as @neroden complained about Tesla service... nearly everything he's complained about with Tesla service has applied to VW service in the US market, especially on the TDIs. I think about the only thing VW hasn't done is avoid letting you schedule an appointment, and then I've personally had a dealer throw out a ridiculous quote ($1500 for a heater core... but then none of the independent shops wanted to do it either, and I ended up selling the car partially because of that...) to avoid doing a job before, so...)
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That car looks like an outdated 90s POS....
It looked awesome when we were driving behind one in Napa. But then he turned into a gas station and we went from 'wow' to 'nahhhh'. Its a hybrid.
How many Karmas were sold? Was the i8 really the best selling car in the segment? Maybe Karma was counted as a sedan.
RobStark
Well-Known Member
Tesla made a grand total of 2450 Roadsters.
These are sports cars not sedans nor crossovers.
20k in six years for a $147k Plus (2019 price) 2 door sports car is massive.
If Tesla sells 20k Roadsters 2.0 over six years at $200k Plus I will be extremely happy with the result.
That makes money AND is a rolling billboard for the company.
That's hilarious... not with a 129HP electric motor and 3-cyls gas engine they're not. They're better looking Prius's
If you want to serve a niche market, sure. If you want to move the needle on BEV adoption, it's a fail.
Sure, but it's a halo car designed to raise the awareness for the company also pushing 100's of thousands of compelling "regular cars".
BMW instead built a sexy, but lackluster spec expensive car, and then the weirdmobile i3.. the only thing one did was highlight how much the other thing looked like a bug... well that's not strictly true... they did another thing also: Confuse everybody with the "REX" thing and give those who did purchase it the thrill of having a motorcycle engine to listen to.
Questionable on both counts.
RobStark
Well-Known Member
That is hilarious. This design, 369 hp and 0-60 in 4 seconds and handling like a roller coaster makes it a sports car.
It was never intended to move the needle on BEV adoption. It was intended to move the needle on PHEV adoption. Which it has.
Tesla built a sexy Model S, less sexy Model X, a prius-like Model Y and now a wierdmobile Cybertruck that mainstream full size truck buyers reject.
It really isn't.
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JRP3
Hyperactive Member
Come now, you're better than that.
Doggydogworld
Active Member
My Lotus Elise is considered to be a quintessential sports car despite barely having half the i8's power.
There are a couple of i8s near me. I like them and they draw plenty of attention, but both the i3 and i8 always seemed kind of random.
bhtooefr
Active Member
Your Elise is also like 1350 lbs lighter than the i8. There's entire sports cars that weigh that much (granted, they're either from the 1960s or earlier, are kit cars, or both (I'm looking at you, Caterham (Lotus) 7)). That kinda helps its sports car cred.
For that matter, a 2011 Tesla Roadster is 670 lbs lighter than an i8.
(Some may say that that's not fair, the i8 has a back seat. But it's a useless back seat, and being a 2+2 has less sports car cred than a straight 2-seater.)
For that matter, a 2011 Tesla Roadster is 670 lbs lighter than an i8.
(Some may say that that's not fair, the i8 has a back seat. But it's a useless back seat, and being a 2+2 has less sports car cred than a straight 2-seater.)
I believe the later version i8 which I think they call the Roadster eliminates the back seat.
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