Still the Gold Standard Among Hybrids
By Erin Riches, Senior Editor Email
Date posted: 03-24-2009

MPG is still what you think about when you drive a 2010 Toyota Prius.

You can't stop watching the hybrid car's instant fuel economy bar graph. In the 2010 Prius, this graph has moved from the navigation screen to the dash-top instrument panel, so playing the Prius mpg game doesn't force you to take your eyes far from the road ahead. It's fun in a way that Jeff Jarvis, the author of What Would Google Do?, would surely understand.

And to its credit, the 2010 Toyota Prius is more open to letting you have fun than any Prius before it. Come late May when this car appears at dealerships, you'll meet a Toyota Prius that doesn't need you to micromanage its behavior.

Feels More Normal To Drive
Point the famous hybrid hatchback down the freeway and the 2010 Toyota Prius feels uncharacteristically stable and secure. Even better, the car's electric-assisted power steering (EPS) has a reassuring weightiness to its on-center response and reasonable precision when you steer into a corner.

You don't take this kind of stuff for granted on a hybrid, and indeed, the Prius' move to Toyota's current MC platform architecture (shared with the Corolla, Matrix and Scion xB) has transformed this car's personality.

Dimensionally, the 2010 Prius hasn't changed much. At 175.6 inches, it's only 0.6 inch longer than the second-generation car, and it rides on the same 106.3-inch wheelbase. Track width is the only difference of note, as the car's wheels are 0.7 inch farther apart in front and 1.5 inches in back. The suspension still consists of struts in front and a torsion-beam setup in back. More significantly, though, the structure of the hybrid's front end is 100 percent more rigid than before; its rear is 50 percent more rigid; and the whole chassis is 50 percent more resistant to torsional flex.

In addition, Toyota has added steering caster to enhance the car's straight-line stability, plus the steering rack is rigidly mounted to improve on-center feel. The steering ratio remains a leisurely 19.1:1, but the electronic-assist power steering has been recalibrated to make it feel more like real steering.

Our 2010 Toyota Prius test car is also unusually quiet. The fact that it's a base-model Prius with P195/65R15 89S Yokohama Avid S33 tires, rather than a Touring model with the wider, stiffer P215/45R17 rubber, undoubtedly helps, though Toyota has also upgraded the car's acoustic insulation for 2010.

More Engine
Engine noise is also way down in our 2010 Toyota Prius, as last year's 76-horsepower, 1.5-liter engine gives way to a comparatively torque-rich, 1.8-liter inline-4 with variable intake valve timing. Power output is rated at 98 hp at 5,200 rpm and 105 pound-feet of torque at 4,000 rpm.

Running on the Atkinson cycle, this 1.8-liter is the single biggest factor in the 2010 Prius' climb to the coveted 50-mpg combined rating (from 46 mpg in 2009). "The main improvement is to reduce engine speed," Chief Engineer Akihiko Otsuka tells us. And with the exception of full-throttle runs on uphill grades, our ears tell us the 1.8-liter is operating at lower rpm. Without a tachometer, though, we can't prove it.

Still, the engine feels less strained than the old 1.5-liter, and this makes for saner freeway drives. Also, our Prius test car averages 52.2 mpg on a 115-mile fuel economy test loop that's 60 percent highway driving. Pile on a few dozen more Prius-friendly city miles and mid-50s would be easily attainable.

Additional fuel-scrimping features on the 1.8-liter engine include cooled exhaust gas recirculation (which reduces pumping losses), exhaust heat recovery (which allows the engine to shut off sooner) and an electric-motor-driven water pump that eliminates the need for a power-robbing serpentine belt.

The gas tank still holds 11.9 gallons, but, says Chris Risdon, a product educator for the University of Toyota (the company's sales training arm), "we've eliminated the bladder system, so this is a conventional style fuel tank." So if you're a hypermiler fervently tracking fuel consumption, you should finally be able to get a truly full fill.

But Less Motor
Total system power for the 2010 Toyota Prius is 134 hp, as there's an additional 36 hp coming from the carryover nickel-metal hydride battery pack.

The batteries provide juice for the hybrid car's two electric motors (one a drive motor, the other a generator), which are smaller and lighter this year. Although a smaller electric drive motor can't produce as much torque, this one is part of a new front transaxle that reduces power losses by as much as 20 percent, improving efficiency in compensation.

The transaxle incorporates the planetary-type continuously variable transmission (CVT), which is now gear-driven rather than chain-driven to reduce friction, just like in the Camry Hybrid. It now includes a reduction gear as well, so the downsized electric drive motor can run at higher rpm where it makes more power. Its limit is 13,500 rpm — more than double the previous motor's 6,400-rpm max.

Not All Numbers Are Better
With a bigger gasoline engine and a more efficient transaxle, Toyota predicts a 9.8-second 0-60-mph time for the 2010 Prius. That's about a half-second quicker than most of the second-generation cars we've tested.

However, our best 0-60 run in our base-model tester is 10.1 seconds. If you allow 1 foot of rollout as on an NHRA drag strip, the time drops to 9.7 seconds, which supports the company's claim. Fact is, though, several of the second-gen Priuses have come very close to our 2010 Toyota Prius test car's 17.3-second quarter-mile time and 79.7-mph trap speed.

Curb weight isn't an impediment here, since at 3,060 pounds, our 2010 Prius is barely 100 pounds heavier than the previous-generation car. Instead, it's a matter of priorities: Toyota swapped in the 1.8-liter engine to raise fuel economy. It isn't about improving straight-line performance.

We get similar results in handling tests. Although you can't ask for much better than 0.78g on the skid pad from a fuel-sipping hybrid, the 2010 Prius' 59.1-mph slalom speed is 2-5 mph slower than most second-gen Priuses we've tested. If anything, the car's undefeatable stability control system has gotten more aggressive.

On back roads, the car's extra dose of steering caster creates a strong self-centering effect through turns. Understeer keeps you safe, and truthfully, if you're hammering on a 2010 Toyota Prius, you probably need some looking after.

Brakes Make a Difference
You'll trust the brakes in the 2010 Toyota Prius more than before, though. Pedal feel is still a bit strange because of the customary blending of the traditional friction brakes and the electric motor's regenerative contributions, but the overall response is less wooden than before.

More important, Toyota has put a set of 10.2-inch rear discs on the back to complement the 10.1-inch discs up front. Our best 60-0-mph distance of 118 feet isn't radically better than the 119 feet we got in the most recent '09 tester, but the lack of fade in subsequent stops is an improvement.

Living the Eco Life
To help keep you interested in the mpg game, Toyota has added three specialized driving modes to the 2010 Prius — EV, Eco and Power.

You can use EV ("Electric Vehicle") mode to get the drop on unsuspecting pedestrians, provided they don't exceed 25 mph or stray further than 1 mile. And with its promise of quickened throttle response, Power mode will please latter-day Prius drivers who already blow past us at 85 mph on the freeway.

For dedicated Toyota Prius drivers, though, Eco mode is the real deal. It reduces throttle response, but also smoothes it out, so it's a pretty painless way to raise your mileage if you can tolerate the reduced air-conditioner oomph.

In any of these modes, you'll see an additional "Eco" symbol on the instrument panel if the onboard computer determines your combination of throttle angle and vehicle speed constitutes efficient driving.

Strangely enough, the parameters for Eco driving vary by market. The most conservative parameters are applied to Japanese-spec Priuses, while the most leeway is given to European Prius drivers. The Europeans, one Toyota engineer told us, demand sharp throttle response, but evidently don't want to be made to feel that they're not driving in a frugal manner.

We also learn that the Eco parameters for U.S.-market Priuses were finalized on Los Angeles area freeways, so even if you hate L.A. drivers, they've left their imprint on your 2010 Toyota Prius.

Equipping Your Prius
There's nothing lavish about our base-model 2010 Toyota Prius, which has cloth seats and nothing more extravagant than an optional JBL audio system upgrade and Bluetooth capability.

You can take your 2010 Prius far uptown, though, starting with a roof-mounted solar panel. It powers an auxiliary ventilation system that keeps the cabin from getting too hot or cold while you're parked at Whole Foods. It will not recharge the battery pack even a little (apparently because in Toyota's internal testing, the solar panel generated a frequency that could disrupt radio or cell phone use). But nobody outside the Prius community has to know this.

There's also an advanced technology package that turns your Prius into a Lexus that parks itself, keeps you from inadvertently departing your lane and battens down the hatches in the event of an unavoidable collision.

Oddly, you can't get a USB port as a factory option. Every Prius with a navigation system can have Bluetooth music streaming as a work-around, but at this point, running a hard line from your iPod is still the standard for integration.

50 MPG Is the Gold Standard
You don't need us to tell you that the 2010 Toyota Prius won't stimulate your senses. It's not that kind of car. The third-generation Toyota Prius is, however, a vast improvement over its forbears. It finally offers the kind of safe, predictable road manners expected of a modern car. And it now has a gas engine capable of moving around 3,000 pounds of hybrid piety.

Yet it's that 50-mpg combined fuel economy rating that will ensure the continued celebrity status of the new Prius. It doesn't matter whether it makes perfect economic sense to spend $25,000-$30,000 on a car just because it hits this magic number. After all, driving the most fuel-efficient car in the nation is a psychological victory, and it's a more attainable one than driving the quickest car (for the moment, the $82K Nissan GT-R).

And should you ever doubt your motives in buying a 2010 Toyota Prius, just have a look at its useful backseat and expansive hatch area. You see there? It turns out that you are one of our most level-headed and conscientious citizens. Thanks for playing.

The manufacturer provided Edmunds this vehicle for the purposes of evaluation.

Driven: The 70-MPG 2010 Toyota Prius
What happens when you unleash a pack of automotive journalists on the newest hybrid on the block--and challenge them to beat the chief engineer's best fuel economy?

If you plan it right--set a low bogey--you'll let journalists write the best story on the 2010 Toyota Prius from behind the wheel. The fuel economy story. That's exactly what Toyota did at the Napa unveiling of the new Prius, where car writers far and wide topped the engineer's 62.9 mpg by as much as 12 mpg.

On a total loop of 33.2 miles, I logged in at 69.5 miles per gallon, without even really trying--just coasting to stops, accelerating very gradually and using the Prius' EV mode to coast into our host hotel. It's 70-mpg performance, if you're only counting two sig figs--and even that was strictly mid-pack. One pair of drivers hit 75.3 miles per gallon under vaguely real-world driving conditions.

Fuel economy is what the 2010 Toyota Prius is all about. Even today, with gas back under $2 a gallon and hybrids selling way more slowly than in 2008, the Prius is still the sales champ of the gas-electric category. No other car even comes close, and no other car is so closely identified with greener driving. The news of the 51-mpg city rating for the Prius, and our mind-blowing economy ratings, simultaneously takes some air out of the lower-mileage 2010 Honda Insight and 2010 Ford Fusion Hybrid, while also also making us wonder why anyone would really need a plug-in Prius.

The 2010 Prius is significantly improved over the prior car (confession: I'm an owner of a 2004 model) in dozens of small ways. Along with exceptional fuel economy, it benefits from a taller, more airy cabin and improved driving feel. It's also a more upscale effort in general, likely because of its close family relationship to the new 2010 Lexus HS 250h.

At the same time, the new Prius is still a hybrid, in driving feel and in appearance. Some of the upgrades have cut down on utility, like the nicer center stack between driver and front passenger that reduces knee room. The biggest concern right now is price: exactly how much will the new Prius cost, and will top versions break the $30,000 barrier?

Pricing comes later, as the Prius goes on sale in a few weeks. Until then, our Bottom Line on the 2010 Toyota Prius is that it ups the ante in the hybrid world with 51-mpg city fuel economy and a finer style.

Get our hands-on road test on our 2010 Toyota Prius page, along with dozens of high-resolution photos.

When you sit in the 2010 Toyota Prius, you notice all those little things that provide the "Prius experience" – the shift lever, information screen, center-mounted instrument panel – are all present, but they're slightly different and noticeably improved. The time it takes to adapt to the revised interior is emblematic of the new Prius experience. It's the same oddly shaped hybrid that almost two million buyers love, but it gets better mileage, looks sharper and is packing more technological whiz-bangery than any vehicle this simple to drive has the right to.

We recently tested the 2010 Prius at its North American launch through the vineyard-covered fields and hills surrounding Napa, California. Through it all, the hybrid, officially rated at 50 mpg, performed well and delivered better-than-expected fuel economy. In fact, when we pushed the car's eco prowess by using the EV mode as much as possible and employing a few other tricks, we blew that EPA estimate out of the water by almost 15 mpg. And we weren't alone.

The Prius' chief engineer, Akihiko Otsuka, drove a 33-mile route in and around Napa and averaged 62.9 mpg. During the drive week, he levied a Beat-The-Chief challenge to anyone who wanted to take him on. AutoblogGreen was able to get the in-dash display to read in the mid- to low-70s for most of the route, but the last ten miles on a busy 55-mph road dropped that to 64.5 mpg. Not bad, but only good for a standing near the absolute bottom of the rankings among other journalists. Overall, the best score was 94.6 mpg, although that involved some less-than-real-world driving behaviors and conditions. The best "honest" score was 75.3 mpg. In all, about half of the journalists were able to get over 70 mpg, while the rest, save two, were able to get more than 66 mpg.