Range Testing the Audi E-Tron Motor Trend - Audi E-Tron EV Forum
 
LinkBack Thread Tools
post #1 of 1 (permalink) Old 11-10-2019, 12:09 PM Thread Starter
Member
 
Join Date: Jun 2019
Posts: 54
Range Testing the Audi E-Tron Motor Trend

Motor Trend recently tested the e-tron's range to see how it compares to its EPA estimate and to Tesla.

Here's what they wrote. https://www.motortrend.com/news/audi...range-testing/

Quote:
The Teslarati have gone unchallenged for years now, but have no fear, the Germans are finally here. From the Volkswagen Group, the first assault is two-pronged: Porsche with the Model S-fighting Taycan and Audi with its E-Tron SUV.

The folks with the four rings have earned some well-justified criticism in the range department. EPA testing for the E-Tron reported just 204 miles of range per charge—significantly less than the Jaguar I-Pace (234 miles) and Tesla Model X Long Range (325 miles). Audi compensates with the ability to charge at a rate of 150 kW, besting the Jag but not quite matching the Tesla's 200-kW maximum charging speed.

But we don't want to just take their word for it on all this, do we? Of course not! Audi was kind enough to toss us the keys to an E-Tron for a week out in the desert, where we were able to test the new electric SUV's range and charging abilities. Here's what we found.

Round And Round
Our procedures began with highway testing on the 7.5-mile oval at the Honda Proving Center in Cantil, California. With a full charge, we hit the road.

But first, what's a full charge in an Audi E-Tron? Well, its battery pack is rated at 95 kW-hr, but the electronics only allow you to consume 83.6 kW-hr to protect the longevity of the drivetrain. A kilowatt-hour (kW-hr) is a unit of potential energy, and there are 33.7 kW-hr per gallon of gasoline, though keep in mind that in an electric car, a much greater percentage of that energy actually reaches the road. For the E-Tron to achieve its 204-mile range figure, it would have to achieve an efficiency of over 2.4 miles per kW-hr, given that 83.6 kW-hr * 2.4 mi/kW-hr = 200.6 miles.

Around the oval track, with the air conditioning set at 70 degrees and an ambient temperature of 105, here's what we got: 2.1 mi/kW-hr at 65 mph, 2.0 mi/kW-hr at 70 mph, 1.9 mi/kW-hr at 75 mph, and 1.8 mi/kW-hr at 80 mph. If we extrapolate those numbers to calculate total range, even running at 65 mph the E-Tron would tap out after just 176 miles (83.6 kW-hr * 2.1 mi/kW-hr = 175.6 miles), significantly short of the 204-mile EPA estimate.

There are reasons that explain why our testing on the highway loop reported lower numbers. First, this was purely a test of highway driving. Electric cars are less efficient at higher speeds due to increased aerodynamic drag, which explains why the efficiency figure dropped as our rate of travel increased. Plus, because this was steady-state driving with very little acceleration or deceleration, the E-Tron wasn't able to recover any energy through the braking system to extend its range. EPA range testing is performed on a mix of city and highway roads. When we add to the equation that our test car was running heavier-than-standard 21-inch wheels (the EPA test vehicle rode on 20-inchers) and operating in 105-degree heat, our numbers make a lot more sense.

(For the record, an Audi representative told us that in their own testing, the only situations in which the E-Tron returned efficiency and range figures significantly lower than EPA estimates were when it was being driven uphill, dynamically, or in the cold.)

Charge Up
With about 5 percent charge left, a "turtle" mode kicked in, limiting available power output more and more as our state of charge decreased. After limping to the charger and plugging in, we discovered an aspect of the charging experience that could be a huge turn-off for potential owners.

The car can get real hot.

There's a function called Auxiliary Air Conditioning, which offers up to 30 minutes of standard air conditioning while charging, but it's not available if the car's at anything less than a 25 percent state of charge. So if you're taking a summer road trip in your E-Tron and depleting the battery fully, don't plan on sitting in the car while you fill up on electrons. This is an especially rude hit as Tesla introduces Netflix, Hulu, and YouTube functionality to keep owners entertained as their cars are charging—and doing so in air-conditioned comfort from any state of charge.

Charging its battery on the 50-kW charger at the Honda Proving Center, the E-Tron is nothing special. For those not fully briefed on EV technojargon, the 50-kW rating refers to the rate at which the charging station will charge the battery. I find it helpful to think of a 50-kW charger as charging at "50 kilowatt-hours per hour" (the units cancel out) because it's easier to equate to the "gallons per minute" flow rate at a typical gas station.

The big draw (get it?) for the E-Tron is its capability to charge at a rate of up to 150 kW, which Audi says can restore 163 miles of range in just half an hour. Problem is, there aren't too many 150-kW non-Tesla public chargers around; our closest station was over 100 miles away in Baker, California. Time for a little road trip.

Quest For Electrons
Not only would the trip out to Baker afford us the opportunity to test Audi's 150-kW charging claims, but it would also give us a chance to get an idea of the E-Tron's range in the real world. The roads between Cantil and Baker are mostly highways, sure, but there would be more acceleration and braking involved, and our average speed was likely to be a little lower. More on that in a moment.

When we arrived at the station in Baker, we were greeted by—get this—another E-Tron. It was parked at a 100-kW station, so we plugged in at the 350-kW charger, which, hopefully, would give us an idea of whether this car can charge at 150 kW. Upon plugging in, we saw a charge rate of 137 kW. Hooray!

Unfortunately, that was only sustained for about three minutes, after which the power quickly dropped below 100 kW and then down to 59 kW. It was at this moment that the Audi employee who happened to be driving the other E-Tron chimed in, telling us that it seemed the power station itself had been compromised that day based on his experiences over 8,000 miles of testing.

What about Mercedes' electric SUV? Learn about the EQC here.

Out of curiosity, we switched to a 100-kW plug to see if things would be any different. We saw a consistent 81 kW—oddly, more than we got from the 350-kW charger. Back to the 350-kW station for a second chance, we initially saw 147 kW, proving that the E-Tron is capable of charging at or near 150 kW, but after just two minutes this time, output dropped to 45 kW. Although charging rates reduce as a battery fills up, cross-referencing our results with the E-Tron's Audi-supplied charging curve made it obvious that the station was unwell.


Once we got back to Cantil, it was time to crunch numbers. Our real-world highway journey covered a total of 306.7 miles averaging 48 mph, again with the climate control set at 70 degrees and some usage of the E-Tron's massaging front seat. We averaged an efficiency of 2.2 mi/kW-hr, equating to 183.9 miles of range, which, again, is within the noise of what Audi claims given our tester's larger, heavier wheels and that our testing was mostly at highway speeds.

Our Conclusions
So what have we learned in class today? First, the public fast-charging infrastructure still needs work. Yes, the E-Tron can charge at 150 kW, but because those stations are relatively limited and not entirely reliable, it's not exactly practical to seek them out or consider them in purchasing decisions at this point. Right now, the most common 50-kW chargers take roughly 1 hour and 45 minutes to fully charge the Audi electric.

Second, we have no reason to doubt the EPA's 204-mile range figure for the E-Tron. That figure is still short of the estimates for the Tesla Model X and Jaguar I-Pace, but the Audi is a much more usable car than either of them. Unlike the Jaguar, it has a legitimately spacious back seat. Because of the Tesla's silly falcon-wing doors, you can't put a roof rack on top like you could with the Audi. And let's not forget, Audi's technoluxe interior design might be the best in the industry.

Should Tesla be worried? Yes, but maybe not quaking in its boots. The E-Tron has no learning curve, no barrier to entry. It's just a proper luxury SUV that happens to be a good—not quite great—electric vehicle, and that's OK.
4Rings is offline  
Reply

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome