Toyota’s Prius Prime saves gas money but maybe not the environment

I’ve always wondered what it would be like to own a plug-in hybrid, and recently, fate gave me that opportunity. On a recent trip to Vancouver, I rented a 2024 Toyota Prius Prime for about two months — just the right amount of time to test out North America’s most popular PHEV.

My experience with the Prius Prime

Previously, the words “Prius” and “sexy” were rarely used in the same sentence. However, I think it’s a wedge-shaped Prius Prime introduced in 2023 is something much sexier than its predecessor. The subtle shape also allows for better airflow to improve efficiency. It is lower than before, however, which can make entry difficult for tall or elderly people.

I was comfortable in the Prius Prime once seated, although the materials and options are not as luxurious as some PHEVs sold in the US. On the 10-hour highway to northern Canada I never felt pain (or cold) in the well-bolstered, heated seats. However, visibility wasn’t too great due to the low seating position and thick front pillars that occasionally blocked my view of traffic.

With its folding dash and 8-inch touchscreen, the interior is upscale but not up to par with other EVs I’ve tried recently. It came with wireless CarPlay and Android Auto support which gave me streaming entertainment on long freeways. Driver safety features (lane keeping, adaptive cruise, automatic braking and more) also boosted my confidence in Vancouver traffic. The Prius Prime doesn’t offer true one-pedal activation, but it has a mode close to that.

With a 150 HP two-liter gas engine and a 161 HP electric motor (220 HP net combined), the 2024 Prius Prime (fifth generation) has 100 more horsepower than the previous model. The electric drivetrain is powered by a 13.6kWh battery (usable 10.9kWH) that takes four hours to charge on 240 volts, or twice that on a 120-volt household outlet. That means you can fully juice it up overnight, but it doesn’t have DC fast charging for quick power on long trips. EPA electric range is 44 miles, 19 more than the fourth-generation Prius.

It was surprisingly quick (0 to 60mph in 6.7 seconds) and agile, but with a fair amount of body roll as it wasn’t designed for the race track. Still, given the Prius’ reputation as the staid hippie’s econobox, the new model was a hot mess. I enjoyed driving in all-electric mode more than hybrid mode, though – it was quiet and smooth, with low levels of noise and vibration.

So, how far was I able to drive in that electric car by myself? On the freeway at about 65 MPH, I traveled 30 miles and just over 40 miles in the city. On one trip, I drove from the city center to a place 30 km away and back with a full charge. On one trip, I was able to drive back and forth between the east and west suburbs of Vancouver (13 miles) – a typical commute for most urbanites – in about a quarter.

On a constant charge, my gas mileage over a two-week period (averaging 25 miles per day) was about a quarter of a tank or about $7.50. As for electricity, I used about 70.5kWh during that time at $.085/kWh, for a total of $6. All told, I spent $13.50 on gas and electricity over 350 miles of mixed driving, so the Prius Prime was clearly cheaper to run.

On long trips, it’s still as affordable as a gasoline-powered car, thanks to an efficient ICE engine and hybrid system that’s among the best in the industry. With a full charge of the battery and tank, I started the 547 km trip and traveled 470 km before stopping for gas, with half a tank left. That refill costs about $25.

The real savings and problem with plug-in hybrids

The timing of my test drive was perfect. In October, I saw a European study that concluded that PHEVs are more economical than expected with a large sample size. Engadget’s article about that sparked some interest among owners and potential buyers, so I wanted to compare my experience with the survey points.

First, let’s see if a PHEV is worth the extra money compared to a conventional hybrid. My figures are for the average US consumer and do not take into account state or federal clean air rebates.

When I chose to rent a “compact” car, Avis offered me a mid-range Prius Prime XSE — a model that lists for $37,320 but normally sells for $34,590, according to Edmunds. That was fine with me since it lacked a few features of the XSE Premium, notably the larger 13.2-inch infotainment display and solar roof option. A fully equipped 2026 XSE Premium model with those features costs $41,665.

Since Toyota also makes the standard Prius hybrid, that car offers a good comparison. The equivalent Prius XTE model has a list price of $31,995 in the same configuration, making it $5,325 cheaper than the Prius Prime XSE.

The average US driver covers 13,662 miles per year and gasoline currently has an average price of $3 per gallon. At that range, a non-PHEV Prius driver can expect to burn 273 gallons at 50 MPG (EPA combined) per year, spending $819 on fuel.

A Prius Prime driver, on the other hand, can use 70 to 85 percent less fuel by current EPA or WLPT ratings. If we generously take the high end of those numbers at 85 percent, that reduces the cost of gasoline to $160. That would require using about 2,500 kWh of electricity, though, so at the average US rate of $0.18/kWh, that’s about $450, for a total of $610 (gas and electricity). That means you’ll only save $209 a year, or $2,090.00 over 10 years — not enough to justify the extra price. (Gas and electricity prices, consumption and other factors vary by region and can significantly affect those figures.)

It could be worse than that, according to the European car agency Transport & Environment (T&E). After collecting real-world OBFCM data on 800,000 vehicles, they determined that PHEVs only operate in electric mode 27 percent of the time, instead of 84 percent as estimated by the European WLPT standard. As a result, plug-in hybrids in Europe produce five times more emissions and cost users €500 ($586) more per year than previously thought. Those numbers are about the same in the US.

How could the controllers be wrong about this key data? The first obvious reason is that they underestimate how often people charge their cars. With their short range, plug-in hybrids often need a full charge to get through the day in electric-only mode – but most people don’t.

Why? One reason could be the lack of easy access to a charger away from home. I’ve found them difficult to find and use, often requiring registration or an app rather than just getting a credit card (I’m looking at you, ChargePoint, Flo and Switch Energy). It can also be more expensive than just buying gas, as many companies charge three times the price of electricity or more. Another factor is that corporate or fleet drivers of PHEVs charge less for their vehicles than private owners.

There is one additional and more dangerous reason: The ICE engine often kicks in when PHEVs are said to be operating in all-electric mode, especially in heavy sedans or SUVs. That’s because electric motors alone aren’t powerful enough to function as bypasses.

Bigger batteries can improve overall power consumption, but only up to a point. Beyond 45 miles wide, emissions actually increase. The reason is simple: “Long-range PHEVs are the heaviest in the dataset, averaging 28 percent more mass and 33 percent more engine power than the group just below,” T&E wrote.

Overall, I enjoyed my time with the Prius Prime and found it fun, practical and cheap to drive. A very economical PHEV because it has excellent electric range and enough power that the ICE engine rarely needs to kick in. At the same time, it offers the highest EPA mileage rating of any non-EV sold in North America. If I’m in the market for a new car, the Prius Prime will be at the top of my list.

However, I also learned that PHEVs do not reduce emissions or save consumers as much as regulators and manufacturers have promised. Governments are to blame for much of that, as they overestimated the overall electricity consumption of PHEVs and failed to support the charging infrastructure needed to make them work.

The responsibility also falls on car manufacturers and consumers. Consumers want SUVs, but manufacturers don’t make the electric motors in PHEVs powerful enough to run all the time in EV mode or provide fast DC charging. At the same time, drivers fail to charge their cars regularly. Until those issues are resolved, in my experience plug-in hybrids can be a poor substitute for EVs in terms of carbon emissions and a less economical option than conventional hybrids.