As automakers look to meet the consumer demand for BEVs with around 300 or more miles of EPA range, the size of battery packs are getting larger as well. Across the BEVs currently available (or that will be in the next few months) in the US, they average (mean) 82.8 kWh and the median battery size is 78 kWh.

For PHEVs, the mean battery size is 14.9 kWh and median is 14 kWh and mean range is 28.4 miles (EPA) of range versus 285.4 miles of range for BEVs.

Average Electric Miles Per Battery Size kWh

When comparing the ratio of average battery range to average battery kWh, BEVs are significantly more efficient on average with 3.52 miles per kWh versus 1.91 mile per kWh for PHEVs. Using the median numbers, BEVs have 3.62 miles per kWh versus 1.86 mile per kWh for PHEVs. Looked another way, BEVs on average achieve 1.8 more miles per kWh from their powertrains.

BEVs in general are more efficient than PHEVs due to most (not all) BEVs being designed from the ground up for efficiency and as dedicated fully-electric powertrains. Whereas the battery packs and electric powertrains for PHEVs must be added to and integrated with a gas-powered engine and related parts and systems. With the exception of shared powertrain models such as the Kia Niro and Hyundai IONIQ and the now discontinued Chevrolet Volt, PHEVs use electric powertrains that are “add-ons” to existing ICE models.

But of course BEVs and PHEVs have a wide range of levels of efficiency, with, for example, the top five most efficient PHEVs are more efficient than the four least-efficient BEVs.

Most and Least Efficient EVs

The top five most efficient BEVs are:

• Tesla Model 3 Long Range — 4.53
• Hyundai IONIQ Electric — 4.47
• Lucid Motors Air Dream Edition Range — 4.41
• Lucid Air Grand Touring — 4.37
• Tesla Model Y Long Range — 4.35

While the five most inefficient BEVs are:

• GMC Hummer EV Edition 1 — 1.60
• Audi e-tron Sportback — 2.29
• Porsche Taycan 4 Cross Tourismo — 2.30
• Audi e-tron — 2.34
• Porsche Taycan — 2.54

For PHEVs, the top five most efficient are:

• Hyundai IONIQ PHEV — 3.26
• Kia Niro PHEV — 2.92
• Toyota Prius Prime — 2.84
• Ford Escape PHEV — 2.57
• Hyundai Santa Fe PHEV — 2.5

And the least efficient PHEVs are:

• Ferrari SF90 Stradale — 1.13
• Audi Q5 TFSI e PHEV — 1.28
• Jeep Wrangler 4xe — 1.29
• Bentley Bentagya Hybrid — 1.38
• BMW 745e xDrive — 1.42

Though PHEVs are on average less efficient than BEVs, a current and longer term challenge for electrification of personal transportation is a shortage in the supply of battery cells and the minerals used in most current EV batteries, such as lithium, nickel, and cobalt. But the smaller battery packs of PHEV means that roughly 5.5 times as many PHEVs could be produced with the same total battery size as from a single BEV. While BEVs are clearly the future, PHEVs should be a larger focus in the near-term to drive higher sales in the US and enabling a reduction in GHGs more quickly.