On Autos: Hyundai, Toyota hybrids strive to beat Prius’ efficiency

The 2017 Hyundai Ioniq hybrid is a new competitor to the best-selling Toyota Prius. (Brady Holt/The Current)

It’s not easy to find a more fuel-efficient car than a Prius. Toyota’s gas-electric hybrid is now in its fourth generation, and its EPA ratings have climbed with each new iteration. Most of today’s Priuses are rated for a whopping 52 mpg in mixed driving, a figure that climbs still further to 56 mpg in the extra-thrifty Eco trim.

So it’s perhaps not surprising that one of two new challengers for the fuel economy crown is actually a model based on the Prius: the new 2017 Prius Prime plug-in hybrid.

The 2017 Toyota Prius Prime is the plug-in hybrid version of the standard Prius. (Brady Holt/The Current)

While conventional hybrids like the standard Prius recharge their electric batteries during routine driving, plug-in hybrids are charged up at a power outlet for additional gas-free range. Once the battery is depleted, a gasoline engine fires up to keep the car running until you can charge it again.

In the Prius Prime, 5.5 hours of charging time from an ordinary household outlet results in an EPA-estimated 25 miles of all-electric range. Use a 220-volt car charger at home or on the go and that time falls to just over two hours. After that range is used up, the Prius Prime still averages an excellent EPA-estimated 54 mpg.

During a weeklong test of the 2017 Prius Prime, one full recharge resulted in 27.8 miles of all-electric range and a second charge lasted 29.6 miles, both beating the EPA estimate. These figures aren’t impressive next to the Chevrolet Volt that pioneered the mass-market plug-in hybrid — it goes an estimated 53 miles per charge. But recharging the Chevrolet’s bigger battery takes longer, and the Volt isn’t as fuel-efficient: It’s rated for just 42 mpg when running on gasoline, and 106 mpg-equivalent in all-electric driving compared to 133 mpg for the Prius Prime.

The Prime replaces the Prius Plug-In, which was sold from 2012 to 2015. That car could travel just 11 miles in all-electric mode (and always needed the gas engine to go faster than 62 mph), cost thousands more than the regular Prius and had only the most subtle aesthetic tweaks.

The 2017 Toyota Prius Prime is rated to travel 25 miles per electric charge, after which it behaves like a standard hybrid. (Brady Holt/The Current)

Toyota corrected all those issues with the Prius Prime. Unique front and rear ends distinguish it from the standard Prius, and the interior also stands apart for its double-height touch screen — a design cue cribbed from the Tesla electric car. And despite these advantages and the greatly improved all-electric performance, Toyota also lowered the price. The 2017 Prius Prime starts at $27,995 compared to $31,000 for the 2015 Prius Plug-In and $24,685 for the standard 2017 Prius. Factor in a $4,502 federal tax credit for the plug-in Prime — nearly twice the credit available on the 2015 — and the Prime can actually be a better deal than the base Prius.

Like every current Prius, the new 2017 Prime also benefits from livelier driving dynamics than older models. Toyota introduced more responsive steering and improved the suspension composure that result in superior ride and handling. There’s also an interior that’s spacious enough for four adults to sit comfortably, along with the cargo utility of a hatchback.

The 2017 Toyota Prius Prime has a useful double-height touch screen, but some controls are fussy to use. (Brady Holt/The Current)

Inside, the Prius Prime’s bigger batteries and electric motor do show their drawbacks: They cut into cargo space compared to the standard Prius and eliminate a fifth seating position. The competing Chevrolet Volt generally has a tighter cabin in most respects, but Chevrolet did manage to squeeze a fifth seat into the Volt’s second generation.

Not everyone will love the Prius Prime’s flashy dashboard, either. While the larger screen can display a convenient variety of information simultaneously, Toyota eliminated physical buttons and knobs — leaving only the touch screen and other touch-sensitive controls in their place. Moreover, Toyota has bucked the trend toward allowing Apple CarPlay or Android Auto smartphone integration.

If the Prius Prime doesn’t sound appealing, there’s another new way to beat the Prius’ EPA fuel economy ratings — one that doesn’t require off-street plug-accessible parking. That’s the all-new 2017 Hyundai Ioniq, a conventional hybrid that not only costs less than the Prius but also edges out its EPA estimates.

The 2017 Hyundai Ioniq’s gas mileage is excellent but didn’t beat the Prius’ in real-world testing. (Brady Holt/The Current)

The Ioniq also offers a more conventional experience than the Prius, with understated styling, a more user-friendly dashboard, a more solid-feeling ride and a quieter, less buzzy engine. Essentially, the new Ioniq feels like an ordinary economy car that uses a minimal amount of fuel. And with a base price of just $23,085, it’s doesn’t command an unreasonable price premium over a Honda Civic or Subaru Impreza gas-only hatchback, despite its EPA ratings of 55 mpg on most versions and up to 58 mpg on the Ioniq Blue variant.

The Prius, however, retains some important real-world advantages. As long as you accelerate fairly gently, even the standard Prius is willing to remain in gas-free all-electric operation — only summoning the gas engine when you accelerate harder or when the battery runs low. The Ioniq is technically the same, but in practice it’s almost impossible to coax it up to speed without help from the engine. Like the Prius, the Hyundai will shut off the gasoline engine willingly when cruising, but accelerating from a stop — for instance, moving up a few car lengths in rush-hour congestion, or cruising gently between two four-way stops — gives full advantage to the Toyota.

The result: A week of driving around the D.C. area returned 57 mpg, compared to a whopping 69 mpg in a Prius Eco tested last year. That experience is in line with a weeklong test of the 2017 Kia Niro — the wagon/crossover version of the Ioniq hatchback — earlier this year.

There’s also a disadvantage inside the car: Although here too the Ioniq competes well on paper, the Prius is the hybrid hatchback with more real-world passenger and cargo space.

Even on price, Toyota has one trump card: the safety features that come standard. Every Prius and Prius Prime has a suite of crash-prevention technology that includes radar-based automatic cruise control with emergency automatic braking; a lane-departure warning; and lane-keeping automatic steering. The former isn’t offered on the base Ioniq Blue, costs $1,000 on the mid-level SEL model, and is offered only as part of a $3,000 Ultimate Package on the tested Limited. The Ultimate Package also includes lane-departure warning, but the automatic steering feature — though included in some other Hyundais — is missing altogether from the company’s new hybrid.

The 2017 Hyundai Ioniq has a more straightforward and user-friendly interior than the Toyota Prius. (Brady Holt/The Current)

That’s not to say that the new Ioniq is a dud. Many buyers will appreciate the Hyundai’s less aggressively hybrid-like experience, and because neither car will burn much gasoline to begin with, even a 12-mpg difference between the two cars is a comparatively modest gap. Furthermore, although it’s rewarding to coax all-electric miles out of the Prius by feathering the accelerator, the Ioniq’s mileage likely won’t drop as quickly as the Toyota’s if you prefer to accelerate more rapidly.

But the Prius remains competitive on the value front, offers more room and — at least for eco-conscious drivers — the potential for far greater gas mileage. Accordingly, it would be hard to argue that Hyundai has defended the reigning champion, and the new Prius Prime plug-in option only furthers the Toyota’s appeal.

Plug-in versions of the Ioniq are also on the way to D.C. A slick all-electric iteration is already on sale in California with broader distribution expected in the near future, and a plug-in hybrid model like the Prius Prime is slated to debut in the next few months. Buying a car from new can be expensive so you should also consider looking at used cars in las vegas, for a cheaper alternative.