Model 3 SR+ barely less efficient overall than #1 Hyundai Ioniq EV

[sreams]

The numbers are in for the SR+ Model 3, so here we have it:

Tesla Model 3 SR+

134 MPGe combined
140 MPGe city
128 MPGe hwy
25kWh/100mi

Hyundai Ioniq Electric

136 MPGe combined
150 MPGe city
122 MPGe hwy
25kWh/100mi

So if we talk about combined range only, the Ioniq barely edges out the SR+ Model 3, which is impressive considering the wide gap in performance between these cars.

The Ioniq has a significant edge in city driving, perhaps because it weighs 500lbs less due to having a much smaller battery (and a lot less range as a result).

The SR+ 3 has a significant edge in highway driving, which maybe comes down to an advantage in motor design or final drive ratio. Drag coefficients are almost the same for these two cars (0.23 vs 0.24).

Call me impressed. It would be like having a BMW 340i that gets the same fuel efficiency as a Prius.

 

[Watts_Up]

Dud, you cannot compare a Hyundai to a Tesla... Did you ever drove a Model 3?

 

[sreams]

Dud, you cannot compare a Hyundai to a Tesla... Did you ever drove a Model 3?

I own a Model 3. The one in the picture to the left.

Of course they are not comparable as cars. That's what makes it so impressive that a performance sedan is almost identically efficient to the most efficient econobox in the US.

 

[SageBrush]

The SR+ 3 has a significant edge in highway driving, which maybe comes down to an advantage in motor design or final drive ratio. Drag coefficients are almost the same for these two cars (0.23 vs 0.24).

The SR+ has a 4.3% edge in Cd* and a 4.9% edge in highway fuel economy**.

* 1/(23/24)
** 128/122

 

[sreams]

The SR+ has a 4.3% edge in Cd* and a 4.9% edge in highway fuel economy**.

* 1/(23/24)
** 128/122

Front surface area is also part of that equation, and is not known.

 

[davedavedave]

Dud, you cannot compare a Hyundai to a Tesla... Did you ever drove a Model 3?

Read the last line of his post, "Dud"!

 

[Daniel in SD]

Keep in mind that Teslas consume significantly more power outside of the test procedure so true wall to wheel efficiency will be significantly worse. The EPA needs to fix their test.

 

[SageBrush]

Front surface area is also part of that equation, and is not known.

Correct, but that was not your assertion. You said

The SR+ 3 has a significant edge in highway driving, which maybe comes down to an advantage in motor design or final drive ratio. Drag coefficients are almost the same for these two cars (0.23 vs 0.24).

I'm pointing out that the difference in Cd is almost enough to explain the difference in highway fuel economy*. If the Model 3 has other negative factors compared to the Ioniq, then additional positive factors would need to come into play. In terms of the drag equation the other factors beside frontal area that are in play are the car's mass and the tyre rolling resistance.

43/49 = 88%

 

[sreams]

Correct, but that was not your assertion. You said
I'm pointing out that the difference in Cd is almost enough to explain the difference highway fuel economy. If the Model 3 has other negative factors compared to the Ioniq, then additional positive factors would need to come into play.

Just saying that if the frontal area of the Hyundai is less than the Tesla, the overall drag could be identical between them.

 

[SageBrush]

Just saying that if the frontal area of the Hyundai is less than the Tesla, the overall drag could be identical between them.

There are an infinite number of ways that the overall drag could be equal since there are five variables in play. So far we know that the Tesla Cd by itself explains most of the difference by itself. I presume there is a mass difference that favors the Ioniq but I don't know details and the effect will be relatively low for highway driving. The additional force (in Newtons) is the difference in mass * g * the tyre friction coefficient. As an estimate, every 100 Kg extra mass is ~ 9 Newtons so 2.5 Wh per Km. That works out to ~~ 1.5% lower fuel economy per 100 Kg extra mass.

 

[sreams]

There are an infinite number of ways that the overall drag could be equal since there are five variables in play.

I wouldn't say infinite. The Hyundai is a significantly smaller car, and is almost guaranteed to have less frontal area.

 

[SageBrush]

I wouldn't say infinite.

You should, since it is true.

But to swing back to my reason for starting this conversation: A reduction in Cd from 0.24 to 0.23 is far from trivial when it comes to playing the highway fuel efficiency game. You can bet that Tesla spent a LOT of resources to shave that 0.01 off the score. It would equal the effect of shaving ~ 275 Kg of mass off the car.

 

[ifbrock]

where was this info found anyway?

 

[sreams]

You should, since it is true.

But to swing back to my reason for starting this conversation: A reduction in Cd from 0.24 to 0.23 is far from trivial when it comes to playing the highway fuel efficiency game. You can bet that Tesla spent a LOT of resources to shave that 0.01 off the score. It would equal the effect of shaving ~ 275 Kg of mass off the car.

The difference in mass between the Ioniq and the Model 3 is about that much.

 

[sreams]

where was this info found anyway?

The monroney sticker was posted in the "SR/SR+ Waiting Room" thread.

 

[GregD60]

I wouldn't say infinite. The Hyundai is a significantly smaller car, and is almost guaranteed to have less frontal area.

The width of the Ioniq is 72" with a height of 57", the Model 3 is 73" wide and 56-57" wide, so I think the frontal area of the two cars is going to be very, VERY close. Depending on the actual shapes of the two cars, either could have a lower frontal area.

 

[AlanSubie4Life]

Keep in mind that Teslas consume significantly more power outside of the test procedure so true wall to wheel efficiency will be significantly worse. The EPA needs to fix their test.

Yes, assuming the car is driven 10k miles per year, with current software, the approximate Model 3 SR+ efficiency is actually:

750Wh/day*365days/10000miles = 27.4Wh/mi (from battery)

Divide by 0.9 (optimistic) for charging efficiency: 27.4Wh/mi/ 0.9 = 30.4Wh/mi = 3kWh/100mi (from wall)

So, the true efficiency of the Model 3 SR+ is 25kWh/100mi + 3kWh/100mi = 28kWh/100mi (10k miles per year)

This is most likely a best case number; it might be as high as 29kWh/100mi.

 

[ifbrock]

The monroney sticker was posted in the "SR/SR+ Waiting Room" thread.

I think that is suspect though... because at the very top left it says ‘Model 3 Standard Range’ i don’t think we know if the values are for the plus in particular. They could be for the SR @ 220mi Range.