In a previous article, I covered some of the reasons why Tesla vehicles didn’t perform as well in Edmunds‘tests compared to EPA cycles. After getting some suggestions from Tesla himself, Edmunds decided to run his tests again, with better results.
The first round of testing
Before we get to the details of the new tests, let’s go over what happened last time really quickly so we can keep things in perspective.
Edmunds runs its own range test on electric vehicles because EPA tests can be unrealistic for many drivers. In the past, most gasoline and diesel powered vehicles did not get the MPG on the Monroney label, sometimes they fell a little short, and sometimes they fell short. In some cases, this has led to lawsuits and the EPA has reviewed its evidence several times to try and make it a bit more realistic.
Most of the unrealistic nature of EPA testing comes from a combination of higher real-world highway speeds and inefficient driving. EPA highway test cycles peak at around 60 MPH, while actual average highway speed in the US is 65 MPH. On top of that, many drivers take off hard at intersections and then brake hard at the last second as they approach the next stoplight. All of this leads to wasted fuel in ICE vehicles and less range in electric vehicles. Test drivers taking an EPA test know how to do a better job of driving efficiently, which makes EPA tests unattainable for the average jerk in many cases.
Edmunds decided to see what EVs achieve by driving like normal people do instead of going through the EPA test cycles. While there are rumors that the company only charged for Tesla vehicles at 90%, in reality that is not the case. They charge each vehicle as much as the vehicle is allowed to charge, but note in the data when a manufacturer does not recommend a full charge. Once loaded, they take a vehicle and drive it on real highways at real highway speeds until the guess meter reads zero miles.
How Edmunds Tests compared to EPA results may vary, and for a lot. Unsurprisingly, many vehicles do not perform as well in Edmunds tests like they do on EPA cycles (which, as I explained, use lower speeds and often careful drivers). However, some really got over it. For example, the Porsche Taycan did much better at high speeds than EPA tests. This could be due to the second gear the vehicle can use on the road (which wouldn’t have helped it much in EPA testing).
The second round of testing
Tesla engineers didn’t like the results, because having none of the EPA-rated vehicles on the highway while the competition did better is not a good look for the company. As I’ll go into more information below, this really shouldn’t matter, but the public trusts the EPA more than it probably should. Tesla engineers gave Edmunds testers a number of tips, the biggest problem being the “reserve” range that vehicles still have when the range indicator says zero miles left. If Tesla vehicles got some credit for those 10 to 15 miles of extra range, engineers argued, they could hit EPA numbers at Edmunds evidence.
When they tested again, they did so on a track so they could see how far a vehicle goes before it comes to a complete stop. Obviously this is not something you can do on a real highway without taking a lot of risks. Once they got that number, they took the cars out onto city streets to see how far they went beyond zero, and they got mixed results. This is because the amount of buffer remaining doesn’t always necessarily give you the same number of miles, because conditions differ.
Did the end work out? Two of Tesla’s vehicles met their EPA numbers, one could reach EPA rank, and the others definitely fell a bit short. Here is their video showing how they got the results and what results they got.
Bottom line: EPA numbers don’t matter
Instead of doing what many Tesla fans are doing on Twitter and Facebook (criticize Edmunds), I will agree with what they said at the end of the video: we can’t really trust government numbers.
My normal distrust of government officials aside (hey, even this law school professor says you should never talk to the police), there are important reasons why we shouldn’t trust the EPA rank and file. MPG numbers. Most of all, they aren’t realistic for real-world driving, unless you’re talking excessively. If you want to set the cruise control to the speed limit plus five MPH (or more), and you like to have a little fun while driving, then you can forget about getting the EPA number. It just won’t happen unless you really want to and are willing to sacrifice fun, your time, and even safety to get there in most cases.
It is not really a fault for Tesla vehicles when they fall short of the EPA number. It is a failure of the government. If the EPA were serious about giving customers realistic numbers, it would require manufacturers to log ranges at different speeds at various temperatures rather than having a complicated test cycle that no one will ever drive. If Monroney’s decal had this data in a table, people would realistically know what to expect on the road. Going 55 on a horrible urban highway in a coastal state will give you a much higher range than you would legally achieve going to 80 or 85 on a rural Texas highway or turnpike.
Let’s be realistic. Nobody wants to send their children to a school that teaches for the test. We want our children to attend schools that teach for real-world performance at work or in further education. What should really concern us is what you can do with an electric vehicle in the real world, and not how good an electric vehicle is in a government test. As many industry owners and fans know, Tesla vehicles have excellent real-world performance, the best charging network in the US by area covered, and decent durability.
Hitting the EPA numbers is like winning a popularity contest at a state hospital. Won? Yes! But you’re not necessarily going anywhere yet.
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