How they test electric cars to establish range and MPGe
Hey folks Cooley again got another one of your emails about high tech cars and modern driving this one comes in from Peter a he's up in vancouver washington says I'm in the market for a plugin vehicle.
I've noticed there's a veritable alphabet soup of range estimates, what makes these also different.
and what is the process used to measure EV range?
This is kind of a complicated era, Peter.
When you look at a car sticker it used to be pretty simple.
City, highway, average, very understandable.
Today, we're getting into a different measurement on top of those in a plug-in hybrid.
And that is we're going to add in MPGe.
Now, MPGe Has to be defined first.
Miles per gallon equivalent.
The construct here is that there is 115,000 BTU of energy in a gallon of gas, and that is equivalent to 33.7 KWH of electricity stored in a battery.
Okay, now there's our equivalent in terms of energy to energy.
For example a 2019 Nissan Leaf Plus has a 68 kilowatt hour battery.
Divide that by our 33.7 kilowatt hours, and you get about 2 gallons of electricity.
That doesn't sound like it's gonna get you very far does it?
Except an electric car is much more efficient than a combustion car.
EV Motors can run at about 85% efficiency.
Or a gas engine, at best, converts about 25% of the energy in a gallon of gas into motion down the road.
So the EPA is tested, that 19 leaf for example, and found that it gets an 108 miles out of electricity equivalent to a gallon of gasoline's energy, hence 108 MPG equivalent.
Now, on the plugin hybrids like you're looking at, you're gonna see 2 numbers, MPGe and MPG, because the car runs in 2 modes in a varying mix depending how you drive it You're gonna see those two separate until further notice.
There is no easy way to put them together into a single efficiency number because it's so highly dependent on how you drive the car, what kinds of driving you do.
Some folks with plug-in hybrids dip into the gas engine quite a bit Others almost never do, and have to worry about their gasoline going stale.
They run so much of the time on pure electric only, and there's no way to put that together mathematically.
Because we have to predict how you're going to use the car, which isn't possible.
Now just when you're thinking it's a simple math problem to figure out the electric range.
Take the kilowatt hours of battery capacity Divide that by something and get a number of miles.
Of course it isn't that simple because every car is engineered differently.
Some used to kilowatt hours in their battery more efficiently than others.
They are just better designed cars or more modern.
So what do you do is you do an EPA test cycle, as you asked about, to find out what a car will get [UNKNOWN], never mind what the inputs are to that.
And that test goes a little bit like this The car's battery is fully charged and then its packed over night to settle.
The car is then put on a dynamometer its not run on the road.
The first run it through a so called city cycle of driving behavior until the battery is depleted, then the batter is recharged from an AC source not a DC first charger The kilowatt hours that that recharge put back in are divided by the number of miles the car drove on the cycles just before it went empty, and there is your MPGe number, but not quite.
To account for real world usage, terrain, climate controls, things like that, there's kind of a fudge factor.
They take that number and multiply it by 0.7.
to shave a significant amount off to keep the number conservative and again embracing lots of different factors that may reduce your real world range on electric power.
Now interestingly the AAA just released a new study where they took five popular battery electric cars and ran them in different weather conditions to find out the effect on range.
From your HVAC system when you're running the heater, when you running the air conditioning, I get a lot of emails about this.
What they found is rather strugging.
If you run a battery electric car in 20 degree winter weather with the heater turned up to hit 75 you may save as much as 40% of your range of MPGE.
Now that compared to a 75 degree day which is kind of their index On the other hand if you're gonna be in a warmer climate, 95 degrees, and you're gonna run the A/C to get back down to 75, that could save around 17% of your range or MPG.
Clearly the lesson here is, EV's or plug in hybrids in cold weather running that heater take a much bigger penalty, at least according to AAA, than cooling off your electric car living somewhere hot.
So in some beater there are a ton of test techniques here.
I'm really oversimplifying, and they have real world fudge factors built in to make sure that they are not strictly technical.
And that they're looking at real world parameters that are gonna bring the number down.
Hopefully, you get something pretty accurate when you buy your car and hit the road.
[MUSIC]
Up Next
Crash Testing New Electric Cars Proves They're Typically Safer
Up Next
Crash Testing New Electric Cars Proves They're Typically Safer
See What Makes the Best Tire for Your Electric Car
See What Makes the Best Tire for Your Electric Car
Why Are So Many Electric Cars, Scooters and Bikes Burning?
Why Are So Many Electric Cars, Scooters and Bikes Burning?
Seen the New 2023 Prius? Here's Why It's Turning Heads
Seen the New 2023 Prius? Here's Why It's Turning Heads
The Bestselling EVs of 2022
The Bestselling EVs of 2022
Best Dash Cams: A Buying Guide
Best Dash Cams: A Buying Guide
GM's Electric Pickups Head On: Comparing the Sierra EV to the Silverado EV
GM's Electric Pickups Head On: Comparing the Sierra EV to the Silverado EV
Meet a Mind-Bending Hybrid: The Sono Sion Solar-Grid EV
Meet a Mind-Bending Hybrid: The Sono Sion Solar-Grid EV
These Are the Cars That Qualify Now for the New Tax Credit
These Are the Cars That Qualify Now for the New Tax Credit
Don't Buy an EV Until You See the Most Important Ones Coming in 2023
Don't Buy an EV Until You See the Most Important Ones Coming in 2023
Tech Shows
Latest News All latest news
What to Expect at Apple's May 7 iPad Event
What to Expect at Apple's May 7 iPad Event
Did a Week With the Apple Watch Make Me Use My iPhone Less?
Did a Week With the Apple Watch Make Me Use My iPhone Less?
How Google Tests the Cameras in Its Pixel Phones
How Google Tests the Cameras in Its Pixel Phones
Boston Dynamics' New Electric Atlas vs. Tesla's Optimus
Boston Dynamics' New Electric Atlas vs. Tesla's Optimus
What is the Fediverse?
What is the Fediverse?
The Missing Piece to Apple's Eco-Friendly Mission
The Missing Piece to Apple's Eco-Friendly Mission
Most Popular All most popular
First Look at TSA's Self-Screening Tech (in VR!)
First Look at TSA's Self-Screening Tech (in VR!)
Samsung Galaxy S24 Ultra Review: More AI at a Higher Cost
Samsung Galaxy S24 Ultra Review: More AI at a Higher Cost
'Circle to Search' Lets Users Google From Any Screen
'Circle to Search' Lets Users Google From Any Screen
Asus Put Two 14-inch OLEDs in a Laptop, Unleashes First OLED ROG Gaming Laptop
Asus Put Two 14-inch OLEDs in a Laptop, Unleashes First OLED ROG Gaming Laptop
Samsung Galaxy Ring: First Impressions
Samsung Galaxy Ring: First Impressions
Best of Show: The Coolest Gadgets of CES 2024
Best of Show: The Coolest Gadgets of CES 2024
Latest Products All latest products
2025 Audi Q6, SQ6 E-Tron: Audi's Newest EV Is Its Most Compelling
2025 Audi Q6, SQ6 E-Tron: Audi's Newest EV Is Its Most Compelling
Hands-On with Ford's Free Tesla Charging Adapter
Hands-On with Ford's Free Tesla Charging Adapter
Nuro R3 is an Adorable Self-Driving Snack Bar
Nuro R3 is an Adorable Self-Driving Snack Bar
First Look: The $349 Nothing Phone 2A Aims to Brighten Your Day
First Look: The $349 Nothing Phone 2A Aims to Brighten Your Day
Best of MWC 2024: Bendable Screens, AI Wearables and More
Best of MWC 2024: Bendable Screens, AI Wearables and More
This Concept Laptop from Lenovo Has a Transparent Display
This Concept Laptop from Lenovo Has a Transparent Display
Latest How To All how to videos
Tips and Tricks for the AirPods Pro 2
Tips and Tricks for the AirPods Pro 2
How to Watch the Solar Eclipse Safely From Your Phone
How to Watch the Solar Eclipse Safely From Your Phone
Windows 11 Tips and Hidden Features
Windows 11 Tips and Hidden Features
Vision Pro App Walkthrough -- VisionOS 1.0.3
Vision Pro App Walkthrough -- VisionOS 1.0.3
Tips and Tricks for the Galaxy S24 Ultra
Tips and Tricks for the Galaxy S24 Ultra
TikTok Is Now on the Apple Vision Pro