Advertisement



Shayne

Well-Known Member
Joined
Aug 9, 2020
Messages
225
Reaction score
267
Location
Northern Ontario Canada
Vehicles
2021 Mustang Mach E Prem ER
Occupation
Engineer
Country flag
1. Companies "self-certify". Run the tests, send the results to EPA.
2. EPA can elect to audit anyone's vehicle and test results, i.e. take the same test vehicle the company used to get its test results, and run it themselves to make sure they are not pulling a "VW diesel". You're gonna have to trust Ford on this one, since the EPA Ann Arbor lab is still basically "COVID closed".
3. I anticipate you will be completely unsurprised by the final EPA range numbers.
What does 3 mean that; the 88 kwh will produce 270 mile (430 km) epa range in an AWD like estimated? I was leaning for 450 km and a small increase; guess now that will be surprising.
540km = 335.5 miles, which would be great, if EPA... will be disappointed if those come out lower than originally planned.
I thought that
NEDC minus 17% for real world
WLTP minus 8% for real world
EPA minus 2% for real world
was a rule of thumb. That places EPA at about a 6% difference but does not line up with the estimated EPA unless there are different batteries 600 (375 mi) x 0.94 = 564 km 352 miles does not line up with an EPA of 300 miles? Different packs for Europe?

EDIT: 600 x 0.94 x 88/100 kwh = 500 km 310 mi?
 
Last edited:

Maric

Well-Known Member
Joined
Jun 10, 2020
Messages
187
Reaction score
311
Location
CA
Vehicles
Audi Q5 to Grabber Blue FE
Occupation
Engineer
Country flag
Ford should rebrand the Norwegian MachE the 'Valkyrie'.
 

Yoliber

Well-Known Member
Joined
Aug 21, 2020
Messages
83
Reaction score
63
Location
Irvine, CA
Vehicles
TM3 SR+
Country flag
What does 3 mean that; the 88 kwh will produce 270 mile (430 km) epa range in an AWD like estimated? I was leaning for 450 km and a small increase; guess now that will be surprising.

I thought that
NEDC minus 17% for real world
WLTP minus 8% for real world
EPA minus 2% for real world
was a rule of thumb. That places EPA at about a 6% difference but does not line up with the estimated EPA unless there are different batteries 600 (375 mi) x 0.94 = 564 km 352 miles does not line up with an EPA of 300 miles? Different packs for Europe?

EDIT: 600 x 0.94 x 88/100 kwh = 500 km 310 mi?
WLTP -20%
EPA + or - 20%

That's the joke for the electricvehicles subreddit. EPA isn't that consistent from car to car.

There should be a 10-80% average kW and time rating.
 

Shayne

Well-Known Member
Joined
Aug 9, 2020
Messages
225
Reaction score
267
Location
Northern Ontario Canada
Vehicles
2021 Mustang Mach E Prem ER
Occupation
Engineer
Country flag
WLTP -20%
EPA + or - 20%

That's the joke for the electricvehicles subreddit. EPA isn't that consistent from car to car.

There should be a 10-80% average kW and time rating.
I am getting that; like Tesla inflating their numbers to report that -20%. So you think that WLTP can be stated as much as 40% over the EPA numbers.
 

jlauro

Well-Known Member
First Name
John
Joined
Dec 29, 2019
Messages
441
Reaction score
272
Location
Owosso, MI
First Name
John
Vehicles
Charger R/T AWD, Rav4, future Mach-E
Country flag
WLTP -20%
EPA + or - 20%

That's the joke for the electricvehicles subreddit. EPA isn't that consistent from car to car.
Part of it is the EPA allows additional tests to alter the adjustment factor, which on a few companies (like Tesla) have done. From: https://www.caranddriver.com/featur...-factor-tesla-uses-for-big-epa-range-numbers/ :
The default adjustment factor reduces the window-sticker range by 30 percent. So a car that achieves 300 miles of range during the city-cycle dynamometer test ends up with a 210-mile city rating. However, the EPA allows automakers the option to run three additional drive cycles and use those results to earn a more favorable adjustment factor. Currently, only Tesla and Audi employ this strategy for their EVs, and Tesla scores the most advantageous results, with adjustments that range from 29.5 percent on the Model 3 Standard Range Plus to 24.4 percent on the Model Y Performance. If Tesla had used the standard adjustment factor of 30 percent, the Model Y Performance's window-sticker range would drop to 292 miles. But because Tesla takes advantage of the EPA's alternate methodology, the company can instead claim a 315-mile range.​
 

Shayne

Well-Known Member
Joined
Aug 9, 2020
Messages
225
Reaction score
267
Location
Northern Ontario Canada
Vehicles
2021 Mustang Mach E Prem ER
Occupation
Engineer
Country flag
Part of it is the EPA allows additional tests to alter the adjustment factor, which on a few companies (like Tesla) have done. From: https://www.caranddriver.com/featur...-factor-tesla-uses-for-big-epa-range-numbers/ :
The default adjustment factor reduces the window-sticker range by 30 percent. So a car that achieves 300 miles of range during the city-cycle dynamometer test ends up with a 210-mile city rating. However, the EPA allows automakers the option to run three additional drive cycles and use those results to earn a more favorable adjustment factor. Currently, only Tesla and Audi employ this strategy for their EVs, and Tesla scores the most advantageous results, with adjustments that range from 29.5 percent on the Model 3 Standard Range Plus to 24.4 percent on the Model Y Performance. If Tesla had used the standard adjustment factor of 30 percent, the Model Y Performance's window-sticker range would drop to 292 miles. But because Tesla takes advantage of the EPA's alternate methodology, the company can instead claim a 315-mile range.​
You mean at the discretion the administrator; I read that standard. The standard kind of say the administrator can be helpful if the auto maker provides the right incentive. The scalars should be 0.7 mandatory and I would like 50/50 highway/urban. My cals say the same; the Tesla Y used 0.7578 instead of 0.7 which is only a 24.5% instead of 30% reduction. Of course that discretion is realized when they hit the streets and you start to talk real world. They needed to beat the Kona's efficiency and found the right incentive is my guess.
 

Shayne

Well-Known Member
Joined
Aug 9, 2020
Messages
225
Reaction score
267
Location
Northern Ontario Canada
Vehicles
2021 Mustang Mach E Prem ER
Occupation
Engineer
Country flag
Frankly, buyers ought to just ignore EPA and WLTP and wait for YouTube reviewers. They're usually far more accurate.
Ignore? So 68 mile range and I am good to go. ;)

What I am saying is it should be transparently fixed so all can calculate it. It then becomes a fixed variable that can be used to forecast different scenarios. Allow the administrators discretion is where the variable is no longer fixed. All should have the same rules and one test.
 

RonTCat

Well-Known Member
First Name
Ron
Joined
Jul 21, 2020
Messages
199
Reaction score
239
Location
USA
First Name
Ron
Vehicles
Mach-E wannabuy
Country flag
Frankly, buyers ought to just ignore EPA and WLTP and wait for YouTube reviewers. They're usually far more accurate.
What the EPA range estimate will be most useful for is comparing vehicle to vehicle under similar driving conditions, especially if those conditions are close to those used for EPA testing. So if a Mach-e goes farther in an EPA test than a competitor, it is a fair assumption to say it will go farther in MOST other conditions (70MPH cruise, etc). The opposite is also true.

It is why VW had to cheat the diesel tests... their cars were actually dirtier than everyone else's diesel cars, but they wanted to market them as the cleanest. You could run a 1000 "actual emissions" tests on a vehicle, and get a different result based on drive type and measurement equipment. It would be near impossible to get show VW diesel vehicles were dirtier this way. But EPA takes the drive type and measurement equipment variable out of the game, so you get apple to apples, unless you knowingly cheat, which they decided to do.
 

dbsb3233

Well-Known Member
First Name
Tim
Joined
Dec 30, 2019
Messages
3,549
Reaction score
3,282
Location
Colorado, USA
First Name
Tim
Vehicles
2013 Ford Escape
Occupation
Retired
Country flag
Ignore? So 68 mile range and I am good to go. ;)

What I am saying is it should be transparently fixed so all can calculate it. It then becomes a fixed variable that can be used to forecast different scenarios. Allow the administrators discretion is where the variable is no longer fixed. All should have the same rules and one test.
Well ok, let's say take it with a grain of salt. 😉

Agree that it needs to be transparent and consistent. But even more importantly -- a real world scenario. Range in BEVs mostly matters for long road trips. That means high speed, not 48 MPH (which is a joke as a "highway" speed).

I still wish they'd just take them to a NASCAR track, do 10 laps at 70 MPH, and report the miles/kWh (the counterpart to MPG). Now that would be useful info.
 

Shayne

Well-Known Member
Joined
Aug 9, 2020
Messages
225
Reaction score
267
Location
Northern Ontario Canada
Vehicles
2021 Mustang Mach E Prem ER
Occupation
Engineer
Country flag
Well ok, let's say take it with a grain of salt. 😉

Agree that it needs to be transparent and consistent. But even more importantly -- a real world scenario. Range in BEVs mostly matters for long road trips. That means high speed, not 48 MPH (which is a joke as a "highway" speed).

I still wish they'd just take them to a NASCAR track, do 10 laps at 70 MPH, and report the miles/kWh (the counterpart to MPG). Now that would be useful info.
Doesn't matter as long as it is a fixed variable you can with reasonable accuracy predict what that 70 mph result will be. When "At the administrators discretion" to quote the standard all bets are off and it is now all political.
 

dbsb3233

Well-Known Member
First Name
Tim
Joined
Dec 30, 2019
Messages
3,549
Reaction score
3,282
Location
Colorado, USA
First Name
Tim
Vehicles
2013 Ford Escape
Occupation
Retired
Country flag
Doesn't matter as long as it is a fixed variable you can with reasonable accuracy predict what that 70 mph result will be. When "At the administrators discretion" to quote the standard all bets are off and it is now all political.
Not so much on the open end though. There can be a lot more variability extrapolating up from 48 to 70 or 80 than extrapolating between 70 highway and 30 city. Drag can get exponentially worse on the high end.

And more to the point, 48 MPH is just highly atypical as a highway speed. Pick a REAL highway speed as "highway" so you're at least close for most people.
 

Shayne

Well-Known Member
Joined
Aug 9, 2020
Messages
225
Reaction score
267
Location
Northern Ontario Canada
Vehicles
2021 Mustang Mach E Prem ER
Occupation
Engineer
Country flag
Not so much on the open end though. There can be a lot more variability extrapolating up from 48 to 70 or 80 than extrapolating between 70 highway and 30 city. Drag can get exponentially worse on the high end.

And more to the point, 48 MPH is just highly atypical as a highway speed. Pick a REAL highway speed as "highway" so you're at least close for most people.
Agree it could change but should change for all. Does not change my point about not making it political. Does not change my point that with a fix variable extrapolation is possible.
 

dbsb3233

Well-Known Member
First Name
Tim
Joined
Dec 30, 2019
Messages
3,549
Reaction score
3,282
Location
Colorado, USA
First Name
Tim
Vehicles
2013 Ford Escape
Occupation
Retired
Country flag
Agree it could change but should change for all. Does not change my point about not making it political. Does not change my point that with a fix variable extrapolation is possible.
Change for all BEVs, anyway. From a consumer standpoint, I'm not really concerned about a BEV vs ICE comparison. That's so apples-to-oranges anyway. Range is HUGE in a BEV (because of slooow and sparse refueling) but mostly irrelevant with ICE. And it's frankly silly to try and treat gas and electricity the same. MPGe is an almost comical construct.

But range and miles/kWh (MPK?) at city and at realistic highway speeds (like 70 MPH) are hugely important datapoints for potential BEV buyers.

ICE buyers care about MPG mostly for fuel cost reasons. BEV buyers care about MPK & range mostly for "Can I even practically drive this long distances or not" reasons. Far more important.
 

RonTCat

Well-Known Member
First Name
Ron
Joined
Jul 21, 2020
Messages
199
Reaction score
239
Location
USA
First Name
Ron
Vehicles
Mach-E wannabuy
Country flag
Agree it could change but should change for all. Does not change my point about not making it political. Does not change my point that with a fix variable extrapolation is possible.
The US06 cycle has a top speed of 80.3mph. Aero measurements are done to this speed, anything higher would be extrapolated. So for 70mph, any manufacturer has a MEASURED aero drag value.

For testing, almost universally, losses are modeled as F = A + BV + CV^2, where
F= total resistive force on vehicle
V= vehicle speed
A, B, C = coefficents. There is a constant force term, and forces proportional or squared to vehicle speed. Bearing/driveline/brake losses/rolling resistance are generally constant and linear, and wind resistance primarily drives what the C term is, i.e. more aerodynamic vehicles have a lower C.

A very "aero sleek" vehicle with an efficient driveline may only need 6 horsepower to push it along at a constant 50mph. Since it increases by the square of speed, aero forces are dominant above about 50mph. Something like a NASCAR vehicle at top speed essentially uses all of it's engines available horsepower just to overcome aero losses.
 



 









Advertisement


Top