Model 3 vs Kona EV

Good question.. I was wondering the same. I have a friend in Austria who drives a Model X and he doesn't get the advertised range of this Model X with the 100 kwh battery. However, he drives a lot of Autobahn at 80+ mph speeds which explains his lack of range..

 

My guess is that on a long high speed highway trip, the Model 3 will get closer to it's rated range than the Kona. If you have 50% city and 50% highway use, the Kona will get significantly better range than it is rated. This is my guess based on the better aerodynamic of the M3.

 

My son has a LR RWD M3, so am very familiar with his car. While the Kona mostly exceeds its spec'd range, the M3 (spec'd at 500 kms) does the opposite. Having said that, I believe also the Tesla does better at higher hwy speeds. However, since we have never done a trip together with both cars, I can't say for sure how they would compare. Since he has a family, we can't all fit in one car, so it could very well happen one day.

 

I saw a video of a guy driving a Kona at 80 mph and he got about 3 miles per kwh, which would mean 192 miles range on a 258 mile range rating at 80 mph.
There is also another video of a standard range plus Model 3 doing the same. He ended up with an average speed of 70 mph, going 80 mph whenever possible and he got a total range of about 210 miles on a 240 mile official range.
I'm not sure what the average speed of the Kona was but I doubt that he was going 80 mph for the entire trip. If his average was 80 mph, it would explain the difference to the Model 3.

 

I just drove my Kona from LA, CA to Mesa never really exceeding 75mph and had a 4.4mi rate when I got home. I have found 70-75 will get me 3.3 to 4.0 mi/kh. I should note that I’d prefer to do 80-85mph but have heeded suggestions from the forum to slow down to conserve. Also, there was virtually no wind going through the desert and that helped a lot. I’ve found (as many here have noted) that everything is a factor when driving an EV.

 

It certainly would.

 

Everything is a factor when driving an ICE powered vehicle too. EV drivers just notice it more.

I can get 45 mpg in an ICE Elantra if I keep it around 55 on flat. I take it up to 70 and it is more like 37 mpg. That is HUGE efficiency difference. With electric having somewhat shorter ranges and much longer "refill" times, we notice differences more. From a carbon perspective, just dropping the speed limit to 55 from 65 would make a big difference...and only add 10-15 minutes to even 90 minute commute.

I have a friend with a model 3 who says his efficiency drops noticeably when it is raining. I suspect surface tension increases rolling resistance (like picking up a rubber bottle opening pad from a wet counter top is harder).

 

I hesitate to reply as I don't own a Tesla Model 3, but I have read a lot from those who do on the Tesla Motors Club forum.

Realistically, I wouldn't expect the Model 3 to get the full EPA rated range when driving at freeway speeds. As I understand it, the EPA's "highway" testing is done at an average speed of 60 MPH. Most people driving long distances are going to be traveling faster on Interstates and freeways. Faster speeds mean less range; that's just physics, no way around it.

Also, the EPA's tests are done with no climate control, and in winter you're probably going to be running the cabin heater (unless you're a masochist), so that will cut into range even if you leave the car plugged in overnight and pre-heat it before leaving in the morning. If you don't leave it plugged in overnight on a cold (below 40° F) night, then expect to lose a significant amount of range.

Those who aggressively practice hypermiling will of course be able to exceed the EPA rated range, but then they can do that with just about any car. That has a lot more to do with the driver than it does to do with the car.

Just a couple of data points from claims made in one discussion at the Tesla Motors Club forum:

Two owners estimated the range of the LR Model 3 (currently EPA rated between 310 and 325 miles, depending on trim level), when traveling at 80 MPH in summer with the A/C running, at 250 miles. In winter when traveling at sub-40° weather, I would expect even lower range. Above that temp the car shouldn't have to waste energy heating the battery pack, so hopefully it wouldn't be much worse than running the A/C, altho certainly Tesla's resistive heaters do draw more power than the A/C.

Heat pumps used in some of the newer cars have a significant impact on EV range, when used for cabin heating. If I recall correctly, the Kona benefits from that; this is one of the few areas where Tesla's tech actually lags behind some of its competitors.

Unfortunately, Wildeyed, no one can give you a "one size fits all" answer. It depends on your driving style, on whether or not the road is hilly or has significant elevation changes, on the temperature (especially in winter driving), and on other weather conditions. Even rain will reduce the range a bit. The EPA range should be considered optimal range when driving at 60 MPH in fair weather on flat roads. For most people, real-world range at freeway speeds will be noticeably less.

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ICE cars waste about 60% of the energy generated in heat, so actually only about 30-40% goes into range. In EVs, about 80-90% of the energy goes into range. That explains why the impact of atmospheric changes on ICE cars is a lot less.

However, as I understand it, the Tesla's guess-o-meter works differently than the Kona's. At least that's my impression from watching YouTube videos.

I believe it doesn't take into account the past driving as much (or at all) but seems to go from EPA rating. However, don't take my word for it.

But watching especially the YouTube channel out of spec motoring, where on his road trips he always pretty much goes as far as possible. You can tell his efficiency is usually somewhere around 2-3 miles/kwh.

I would thinks that's probably close to what the Kona would get at the same speeds.

As far as I personally can tell from looking at efficiencies, the M3 and the Kona seen to be the top two most efficient cars out there. I would think the Kia being basically the same car as the Kona is probably up there too, with the M3 being number one and the other two following up.

 

Is this because of Carnot cycle limitations for turning heat into work?

 

He tends to speed however - sometimes a lot.

The math to calculate the theoretical efficiency vs speed isn't that hard. But we all know that speeding really kills the efficiency.

 

That's the main reason, I think. Diesel tends to be a bit more efficient, but there is still a lot of waste heat.

 

Haha, I wanted to type fast as possible, not far as possible. Yes, your right!

I didn't look into the carnot cycle too much but I don't think that's the issue. In a combustion engine the heat is not used at all. It is a byproduct. You burn a liquid and you use the expansion of the explosion or burn cycle, not the heat. So all that heat is basically lost energy. That's why ICE vehicles are so inefficient.