# Comparative EV 'consumption'



## Michael Russo (Oct 15, 2016)

Interesting initiative by Bjørn Nyland, with two Norwegian buddies, one with a Model S 70D, the other with brand new Hyundai Ioniq....

My take... Relative weight seems to have, as expected, a predominant effect on 'juice' consumption... though favorable aerodynamics of Model S versus other two seem to help too on highway (cf. Table included, except for the 'city/mix' itinerary...)


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## MelindaV (Apr 2, 2016)

Michael Russo said:


> though favorable aerodynamics of Model S versus other two seem to help too on highway (cf. Table included, except for the 'city/mix' itinerary...)


I thought I'd seen that Tesla was able to get the same Cd on the X as the S.


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## Michael Russo (Oct 15, 2016)

MelindaV said:


> I thought I'd seen that Tesla was able to get the same Cd on the X as the S.


It does indeed seem like that they have the same drag coefficient (0.24) yet because of the relative front cross-section of the X, generating higher relative air friction....

Check out this informative post from somebody on the T≡SLA forum about a year ago...

*georgehawley.fl.us* | April 13, 2016
The X90D weighs 5271 lbs. The S90D weighs 4848 lbs, 423 lbs. less. This translates to about 9% range loss due to increased rolling friction. Both cars have about the same drag coefficient but the X has a larger effective cross-section. How much larger has not been published. Let's take a guess. The X is 66.3" high. The S is 56.5" high.
The X is about 1" wider. If we were comparing rectangles, the cross-section of the X is about 20% larger than the S. So it stands to reason that the X experiences about 15-20% more air friction than the S. At 65 mph the air friction for the S consumes about 180 wh/mile as I recall. The X would therefore consume about 207-216 wh/mile. (...)

Having said this, the Ioniq also has a Cd of 0.24 so I guess I was rather wrong on aerodynamics...


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## Bobby Garrity (Jan 22, 2017)

Well somebody needs to start speculating on the Model 3.

I don't think that it will be quite as efficient as the Ioniq, but I think it will be close. It should produce less drag than the Ioniq, but also will likely be heavier. My guess is that the weight will be more significant.


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## Guest (Apr 26, 2017)

Michael Russo said:


> My take... Relative weight seems to have, as expected, a predominant effect on 'juice' consumption...


Well, this is common understanding, which is mostly incorrect for highway and correct for city. Weight has very little to do with energy spent on rolling. Proof: having one vehicle doing the same task while being empty (like this test) and loaded to the roof (without roof rack and no trailer). I made a trip around 1700km last summer in one direction, 2 passengers, no cargo, and back, 3 passengers, fully loaded with stuff (watermelons, jams, around 300kg of cargo only, plus 120kg person). Difference in fuel economy was 0.1l/100km (0.8 US mpg).



Bobby Garrity said:


> Well somebody needs to start speculating on the Model 3.
> 
> I don't think that it will be quite as efficient as the Ioniq, but I think it will be close.


Yea, I think the same. Ioniq is light. Has more narrow tires - therefore better turbulence in the rims (smaller Cd) and smaller frontal area(A). Ioniq, most likely, will also be smaller, though not sure about drag (Cd). M3 looks extremely slippery.
In synthetic constant speed test Ioniq should be slightly more efficient than Model 3. I think somewhere around 1/3 to Ioniq efficiency and 2/3 to Model S efficiency at stable 90km/h test, no elevation, no HVAC.

My personal bet. Base Model 3 will weight 1750kg, fully loaded 2050kg.


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## Twiglett (Feb 8, 2017)

I'm really hopeful that I'll be able to get pretty good economy in my Model 3, but I have a feeling that I just won't try as hard 
My average over the past year in my Leaf has been 4.5 mile per kW - so about 220ish watts per mile.
Pretty sure I'm not going to get that, but the Leaf has so many coaching tricks.


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## EVfusion (Mar 10, 2017)

arnis said:


> ... My personal bet. Base Model 3 will weight 1750kg, fully loaded 2050kg.


Why 1750 kg (roughly 80% of the Model S)?
Given the Model 3 uses 2170 batteries (higher density) did you attempt to factor that into your weight estimate?
Anyone else attempted a weight estimate?
Bjørn Nyland's numbers certainly show importance of weight to economy, particularly at low speeds (relationship almost linear). So a good weight estimate would help with a city driving economy estimate.
At higher speeds his numbers show how drag becomes much more significant (as you would expect) and the relationship with weight breaks down. The Model 3 has a lower CD but I doubt his numbers help in guessing its impact on economy (as all three cars had a CD of .24). Your experience, Arnis, with weight on the trip was really interesting.
To get a good highway estimate for the M3 we may have to wait until all is revealed in July.


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## Badback (Apr 7, 2016)

EV4Life said:


> I'm really hopeful that I'll be able to get pretty good economy in my Model 3, but I have a feeling that I just won't try as hard
> My average over the past year in my Leaf has been 4.5 mile per kW - so about 220ish watts per mile.
> Pretty sure I'm not going to get that, but the Leaf has so many coaching tricks.


I think that you meant watt-hours. Energy used, not instantaneous power.


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## Guest (Jun 2, 2017)

Because making vehicle more compact does not mean making it lighter.
And using more steel means less weight loss as well.
2170 is "higher density" in terms of volume. 75kWh Model S pack will weight
only slightly more than 75kWh Model 3 pack. As the case will be slightly smaller
and very likely the cooling system will be "more basic" due to less rows of cells
and less modules. Mass of active material inside those two packs will be very similar.
Maximum difference is less than 5%. And mass of anode/cathode/electrolyte is majority.
Due to shorter nose Model 3 must have stronger crash structure in front of the vehicle.
That adds weight.
Weight reduction with "less sound insulation" will be extremely limited. Model S already
has very little sound insulation (suitable for Model 3 vehicle class). It shall not be reduced at all.
Drivetrain will weight less on Model 3. But not 40% less. 
ABS system, steering rack, wheels etc will have similar weight as on Model S.
And this is why my estimations tell me that there will not be 30% weight reduction.


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## EVfusion (Mar 10, 2017)

arnis said:


> ... And this is why my estimations tell me that there will not be 30% weight reduction.


 Many thanks. A very informative answer - I've learnt a lot.


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## EVfusion (Mar 10, 2017)

I don't know if this has already been posted but the _Model 3 May 2017 Tesla Europe YouTube video_ 



 speculates on ranges for the Model 3 60, 60D, 75 and 75D (see 0.28 secs). Gives a lower and upper range estimate for each model. Lowest range 360 km, highest range 508 km. Could not find a source for their estimates.


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