Audi 4.2L DOHC V-8
We already know what you’re going to say: The 10 Best Engines judges were suckered by the same formula that worked 40 years ago for Detroit muscle cars.

Stick a big V-8 in a small-bodied car and watch the concoction go like hell.

It’s a good strategy, really. One that can make just about any big-displacement V-8 perform like a hero. Audi AG’s 4.2L V-8 actually isn’t all that big (only Volkswagen AG makes a smaller 8-cyl.), but it packs a mighty wallop.

The luxury-car-smooth DOHC V-8 comes across like a piledriver in the comparatively light S4 bodyshell. The available torque – a prodigious 302 lb.-ft. (409 Nm) peaking at a wieldy 3,500 rpm – flows as inexorably as lava from a roiling volcano, so one can forgive the high 7,000 rpm needed to attain maximum horsepower.

But unlike its genuine muscle-car progenitors, this Audi V-8 isn’t just about the numbers, and its reportoire isn’t limited to overpowering a compact-car chassis. All the Best Engines judges commented on the subtlety of the S4 package. Unlike some contemporaries that seek to replicate the muscle car – notably General Motors Corp.’s Cadillac CTS-V that employs GM’s 5.7L OHV V-8 – Audi’s V-8 is fitted in the S4 with what seems to be an inordinate level of attention to package-specific development.

The engine’s exhaust tenor, for instance, is permitted to fully express itself only at the appropriate times; the idle burble is a wonderful mix of raw muscle and sophistication, while wide-open throttle tingles the spine. The rest of the time, the 4.2L V-8 minds its own business, something we can’t say of the raucous V-8 bellow always present in the CTS-V.

We also credit Audi engineers for the S4’s excellent handling balance. If you didn’t know there’s a V-8 shoehorned in this car, you probably wouldn’t know it from the driving. And the gear ratios of the 6-speed manual transmission allow the driver to perfectly channel the V-8’s power according to the kind of driving desired, the way a master strokes the head of a well-trained but not-entirely-trustworthy Rottweiler.

Despite its 5-valve-per-cylinder, variable-intake, all-aluminum refinement, Audi’s 4.2L V-8 is hand-grenade-with-the-pin-pulled exhilarating in the S4, an engine hoping you want the explosion to happen.

The beauty is, it never insists. If controlled chaos isn’t your fancy, go on your way content that you’ve got access to a technically intriguing, flawlessly refined, tidily dimensioned DOHC V-8 that also boasts, at 81 hp/L, specific output that bests almost any other V-8 in the market. That includes those passing themselves off as modern-day muscle-motors.

There isn’t an 8-cyl. engine available at the S4’s $45,650 base price that can match the sophistication and outright power of Audi’s magnificent 4.2L V-8.

BMW 3.2L DOHC I-6
There have been other 100-plus-horsepower-per-liter engines to win past Ward's 10 Best Engines awards, but none has enjoyed the staying power of BMW AG’s magnificent 3.2L DOHC I-6 “M” engine.

Credit one thing: BMW’s stalwart inline architecture.

To make in excess of 100 hp/L inevitably requires a high-rpm power peak. Internal combustion engines essentially are air pumps – the more air one can “move,” theoretically the more power one can produce. Moving lots of air typically requires lots of rpm. Ask those Formula One engine guys, who squeeze out hundreds of horsepower per liter, if you don’t believe us.

Past engines that have enamored us in the specific-output stakes eventually have proven to be rather “boring” one-trick ponies. Revving a 4-banger to 9,000 rpm – in each and every gear, all the time – inevitably becomes a grating chore to extract, say, 80% of an engine’s power. Few engines genuinely reward perpetual redline visitation.

BMW’s always-spectacular 3.2L DOHC I-6 is one, however. The inherently balanced inline 6-cyl. layout, so marvelously refined by BMW over the past four decades or so, virtually rejoices in bouncing the tach needle into the scarlet.

Equally important, you the driver enjoy it, too, because even with 103 hp/L, the 3.2L “M” engine gives no quarter to demons of ill-refinement. Spin this engine with disdain, and it responds with nothing but the same velvety demeanor whether turning 3,500 rpm or 7,000 rpm. “Thrashy” simply is not in this engine’s vocabulary.

And who couldn’t smile at the notion of six discrete throttle bodies – one for each cylinder – toiling at your whim? Or better yet, the “M Driving Dynamics Control” electronic throttle control that allows you to select an almost laughably sensitive setting for those six trumpets? It’s a sublime engine-management trick that, frankly, we’re surprised has yet to be replicated – or upstaged – by any competitor.

The 3.2L DOHC I-6 still represents the pinnacle of BMW engineers’ development of the I-6 format.

Although some of its technology-showcase starpower has been eclipsed by the company’s Valvetronic V-8/V-12s and even direct-injection technology, the inline 6-cyl. layout, which BMW says would be foolish ever to abandon, continues in this variant as BMW’s ultimate – and ultimately most significant – expression of its heritage.

DaimlerChrysler 5.7L Hemi Magnum OHV V-8
No other business rewards the latest design quite like the auto business.

So one of the surest tests of a 10 Best Engines winner’s “staying power” is how well it can fight off brand-new engines – particularly when they also happen to be direct competitors in terms of size, cylinder count and market segment. When an incumbent winner outshines newer rivals it battles directly in the market, it’s a testimony to its inherent goodness.

If you accept that premise, then consider the ringing endorsement earned by DaimlerChrysler AG’s 5.7L Hemi Magnum OHV V-8. No engine’s ever had to run a tougher gauntlet to secure a second appearance on the Ward's 10 Best Engines list.

For 2004, the thunderous Hemi had to beat back not only 23 of the 32 engines nominated for a 10 Best position, but two wickedly competent V-8s launched directly against the Hemi in the market: Ford Motor Co.’s redesigned 5.4L Triton SOHC V-8 and Nissan Motor Co. Ltd.’s all-new “Endurance” 5.6L DOHC V-8.

And although both the Triton and Endurance V-8s are unlikely to leave the owners of their respective pickup trucks feeling shortchanged, the simple fact is neither could surpass the Hemi – either in raw numbers or on-the-road punch.

Horsepower and torque ratings have assumed an almost religious importance in the pickup segment. Although Endurance and Triton engineers had the advantage of knowing the target, neither engine came to market with a number to top the Hemi.

It proves the dominance designed into the Hemi right out of the box. The new Triton makes 300 hp. The all-new Endurance, 305. Hemi: 345 horses.

Two critical new pickup V-8s hit the market 40 horses behind the Hemi? Either those 40 ponies were too hard for Ford and Nissan engineers to generate, or somebody in product planning’s asleep at the switch. It might be argued Ford and Nissan’s pickup-truck business plans don’t hinge on horsepower dominance over Dodge, but coming up short by that much is difficult to accept for any reason.

Talking torque, not much separates the three, and in fact the Nissan V-8 has a meager edge. Endurance: 379 lb.-ft. (514 Nm). Hemi: 375 lb.-ft. (508 Nm). Triton: 365 lb.-ft. (495 Nm). So at least it’s an even field in terms of twist.

But beyond the numbers, 10 Best testers believed the Hemi didn’t just beat its new V-8 rivals. It again deserves to be called one of the best of all engines because of its real-world performance and just-right NVH and driveability.

Stick your foot down, the Hemi hauls immediately. Roll down the window, the Hemi bellows perfectly (if perhaps a bit too flamboyantly). Hook up a trailer, the Hemi tugs eagerly.

The Hemi fronts great numbers, but it’s also got soul, a commodity hard to generate in this age of electronically managed might.

DaimlerChrysler 5.9L Cummins 600 OHV I-6 turbodiesel
With DaimlerChrysler AG’s “Cummins 600” 5.9L turbodiesel earning a win in this year’s Ward's 10 Best Engines competition, it’s official: in each of the last three years, there’s been an all-new or significantly revised medium-truck diesel engine. Each year, that new diesel won a 10 Best award.

The breakneck pace of diesel development for the hotly contested, astoundingly profitable medium-truck market is the new world order. Sit back for six months to enjoy your position as king of horsepower or prince of torque and your competitors have passed you by. The numbers – and perhaps more important, the refinement – ratchet up that quickly in the medium-duty diesel game.

DaimlerChrysler and engine-development partner Cummins Inc. credit heavy reliance on computer analytical tools for the new Cummins 600’s overnight burst from last in a three-way race (with General Motors Corp.’s Duramax and Ford Motor Co.’s International Truck and Engine Corp.-made Power Stroke V-8 turbodiesels) to front-runner in terms of both power/torque and refinement.

Dennis Hurst, Cummins’ chief engineer for the Cummins 600, says the incredible NVH improvement the 5.9L inline 6-cyl. Cummins 600 displays over the previous-generation engine actually was a tertiary benefit of his team’s pursuit of more power and precise combustion control that makes the engine 50-state emissions-compliant – without the use of expensive and troublesome add-on exhaust-gas recirculation systems rivals employ to reduce the excess oxides of nitrogen (NOx) emissions that plague all diesels.

So in one fell swoop, DC and Cummins went right ahead and tended to both the numbers and the NVH with the heavily revised Cummins 600. The new name reflects the class-leading torque rating of 600 lb.-ft (813 Nm). And the 325-hp rating isn’t sissy stuff, either.

But we challenge even the most-sensitive of posteriors to tell the difference between 550 lb.-ft and 600 lb.-ft. of torque. At those levels, unless the differences are vast, it’s hard to tell (and GM made late-in-the-year revisions to its Duramax that yield closely competitive 590 lb.-ft [800 Nm] and 310-hp ratings).

No, what blew away Ward's judges was the Cummins 600’s almost unbelievable improvements in NVH and refinement. “This engine makes its two competitors seem like garbage-truck engines,” says one tester. “Even when you first start it on a cold morning, the Cummins lights off and settles into idle like a gasoline engine. It’s remarkable.”

Hurst confirms the new Cummins 600’s combustion noise is markedly reduced, and detail changes like a special noise-isolating valve cover and an optimized turbocharger blade design all contribute to noise and vibration reduction. Of course, the inherently balanced I-6 architecture also presents a fundamental advantage over its V-8 competitors.

And the high-tech combustion control (hundreds of thousands of new lines of ECU software code) that makes the Cummins 600 nationally emissions-certified is a huge matter, too. The only aftertreatment system for this engine is a relatively simple oxidation catalyst to control hydrocarbon and particulate emissions.

All we can say is “Wow.” One tester delivered our bottom-line impression regarding the new Cummins 600: “I could drive this truck every day, and I never would have said that before about a medium-duty diesel.”

General Motors 4.2L DOHC I-6
The first time Vortec 4200 chief engineer Ron Kociba showed his creation to the press almost three years ago, his face had an expression, if you can conjure the image, combining cat-that-ate-the-canary satisfaction with the cautious optimism of a poker player betting a good, but not totally airtight, hand.

Kociba knew his team had developed a pivotal engine. Of that he was certain. Problem was, the new engine had only six cylinders and was earmarked to launch in a midsize SUV segment whose customers seemed increasingly hell-bent on having eight.

Now, with a third-consecutive 10 Best Engines trophy under the Vortec 4.2L I-6’s belt, General Motors Corp.’s decision to green-light the Powertrain division’s straight-6 truck engine proves the General often is capable of excellent feats of engineering. The Vortec 4200 remains a favorite of Best Engines judges because of its crisp responses and no-nonsense power delivery. If the late running back Walter Payton were an engine, he’d be the Vortec 4200: lithe, composed and always capable of the instant burst of power.

“If BMW (AG) decided to make a truck engine, it wouldn’t be ashamed if this was it,” says one Best Engines judge, paying perhaps the ultimate compliment in comparing GM’s inline 6-cyl. with BMW’s fabled straight-6 efforts.

And the Vortec 4200 passes the real acid test, the one that may have given Kociba sleepless nights: When V-8 power became available in GM’s midsize SUVs and their offshoots – so far, the only applications for the Vortec 4200 – much of the press and much of the buying public preferred the inline 6-cyl. instead of the V-8. Mission accomplished.

We see the Vortec 4200 as a win-win for everybody. We get a fabulously responsive, criminally refined, V-8-rivaling 6-cyl. in an SUV.

GM gets an engine that’s easier and less-expensive to produce (one cylinder head instead of two makes for meaningful savings, alone), an all-aluminum, high-volume engine that doesn’t put a hurting on the company’s tenuous corporate average fuel economy position.

All the things that are so right and proper about the Vortec 4200 have kept it comfortably placed on the Best Engines list. It’s surprisingly thrusty, with 90% of its peak torque available by 1,600 rpm. And the glorious inline-6 “rip” is there when snapping wide the deliciously precise, electronically controlled throttle. And heck, it’s only 15 hp short of the 5.3L V-8 it “competes” against.

The Vortec 4200 is one of the most versatile and satisfying engines available at any price. It’s skillfully engineered, brilliantly executed and immensely gratifying to use.

Honda 3L SOHC V-6
There’s probably no better measure of engine-development progress than a contemporary automotive V-6.

When Ward's launched the 10 Best Engines competition a decade ago, V-6s were only beginning to account for a meaningful portion of sales in middle-market vehicles – particularly for imported nameplates – and power levels were unassuming. Here are the power/torque ratings for the four V-6s that won Best Engines awards in 1995: Ford Duratec 2.5L, 170 hp/165 lb.-ft.; GM 3.8L, 205 hp/230 lb.-ft.; Mazda 2.3L Miller-cycle, 210 hp, 210 lb.-ft.; Nissan 3L, 190 hp/205 lb.-ft.

And in 1995, Honda Motor Co. Ltd. had yet to launch its first V-6. Now, 10 years later, Honda’s scorching 3L SOHC V-6, winning a 10 Best spot for a second consecutive year, develops 50 hp more than a same-displacement competitor from a decade ago. Almost 30% increased horsepower, along with better fuel economy and reduced emissions, seems to be genuine progress.

Credit much of the last decade’s power explosion to variable valve timing, a technology that’s been singularly responsible for some whopping horsepower and driveability gains in everything from the smallest 4-cyl. to hulking V-8s. So when Honda engineers got the bug to bring their previously sleepy 3L V-6 to world-class levels of specific output, it was only natural to go straight to the company’s seminal VTEC (Variable valve Timing and lift Electronic Control), the variable valve-timing system that made its contemporary 4-cyl. engines renowned.

For the 3L SOHC V-6, VTEC employs three camshaft lobes for each cylinder’s two intake valves. At low and midrange rpm, each valve is opened by a dedicated rocker arm following a cam lobe that maximizes cylinder mixture, enhancing torque and fuel economy.

But when high-rpm power is required, the engine management system signals a spool valve to lock the two rocker arms to a third rocker located between the two normal-operation rockers. The middle rocker arm, which “freewheels” at low- and mid-range rpm, follows a cam lobe that optimizes high-rpm power production. When the three rockers are locked together, the intake valves open according to the aggressive cam profile.

It’s obvious what the VTEC system does for power production – Honda’s new 3L has better specific output than all but the most-potent variants of Nissan’s 3.5L V-6, which for a decade has stood as the industry’s unparalleled V-6 benchmark. And nobody knows if Honda engineers intended it, but when the VTEC engines “switch” the high-rpm cam profile, the now-signature VTEC “wail” is absolutely symphonic.

At 80 hp/L, we don’t know where V-6s will go from here, but it’s likely Honda, for years focused mainly on its beloved 4-cyl. designs, will be leading the charge.

Mazda 1.3L Renesis Rotary
Where do you start with Mazda Motor Corp.’s new Renesis rotary? That we’re just plain delighted to see the rotary architecture return to thrill drivers with its eerie high-rpm smoothness? That the engine Mazda doggedly has made virtually its own since the 1960s is vastly improved, yet emotive as ever? Or that even with this new-age variant, the rotary has its critics, its foibles?

Its long-term implications for the powertrain sector remain for history to decide, but we’ll vouch for one aspect: Mazda’s new Renesis rotary handily carries on the near-mythic qualities that have earned it one of the most rabid enthusiast followings of any engine in history.

Central to the rotary mythos, of course, is the engine’s basic motion: rotary rather than reciprocating. Because the Renesis’s two trochoids – triangular-shaped rotors with an indented “combustion chamber” in each of the trochoid’s three sides – revolve in a motion that’s essentially circular, the Renesis spins to spectacularly high rpm. Witness the ambitious 7,500-rpm power peak and 9,000-rpm redline. The rotary motion’s advantage is described by Mazda as “theoretical near-perfect dynamic balance with torque fluctuation equal, if not superior to, an inline 6-cyl. engine.” All we know is this: Ram the Renesis to 9,000 rpm and vibration is all but non-existent.

The Renesis’ primary innovation over previous generations of Mazda’s 2-rotor Wankel design is the location of the exhaust ports on the engine’s side housing. By doing so, engineers were able to eliminate or reduce many of the rotary’s intrinsic combustion/exhaust-related bugaboos, which primarily were related to emissions and fuel economy.

The “High-Power” version of the Renesis is differentiated from the standard-power version that generates 197 hp by virtue of a more-complex variable-tract induction system, three rather than two fuel injectors per rotor and an elaborate intake port design that incorporates an extra port governed by a rotating valve that Mazda engineers say effectively amounts to variable valve timing for an engine that has no valves.

The Renesis intake and porting layout is astoundingly complex, and even after engineers explained the system and showed us the diagrams, we’re still not entirely certain how it works.

We just know it works. Judges’ favorite Renesis quality is its primal, mechanical exhaust snarl, which doesn’t approach its full epic potential until pushing past 6,000 rpm (one judge says it’s the sound you’d expect when wringing the neck of the beast in the movie Alien). You find yourself enjoying the snarl for other reasons, though, as the Renesis’ meager 159 lb.-ft. (216 Nm) of torque demands frequent replays to extract maximum performance.

And although the new side-exhaust is claimed to pay extensive engineering dividends, the advantages outside the realm of thermodynamics are difficult for non-engineers to absorb. For example, the new design is claimed to enhance fuel economy (since its inception, the rotary has borne a reputation as a gas guzzler), but we find it tough to praise SUV-like thirst in a 3,000-lb. (1,361-kg) sports coupe. Other high-performance cars at least manage to eke acceptable highway mileage, and we suspect the RX-8’s super-short 4.44 rear axle.

But in reality, our criticisms are window dressing. Ward's judges were overwhelmed by the Renesis, plain and simple. Mazda’s new rotary is a fascinating technical achievement and a superb, emotional performance-car engine.

Nissan 3.5L DOHC V-6
Nissan Motor Co. Ltd.’s sublime 3.5L “VQ” V-6 needs no introduction, being that it’s won a 10 Best Engines award each and every year since the competition’s inception in 1995. That the VQ has cemented itself as the dominant V-6 benchmark is without question – a decade after its introduction, the VQ, amazingly, remains the admitted development target of rivals who will discuss such details.

“No doubt about it, the Nissan V-6 is the 600-lb. gorilla of V-6s,” says a competing powertrain engineer. “No need to bring in a lot of different engines (for comparison), either. Power, torque, brake-specific fuel consumption, just about any attribute you’re looking at, the Nissan’s at the top of the list.”

Rarely has the industry seen such a seminal design. Equally extraordinary, subsequent generations have not lost the edge that made the original VQ variant, which displaced 3L, stand head and shoulders above its contemporaries.

Nissan 3.5L “VQ” V-6 only engine to be 10 Best winner ten years running.
Only now are competitors beginning to approach the alluring combination of power and refinement that have been VQ bywords since its launch. Continual upgrades and detail refinements have kept the VQ at the top of the heap, particularly in terms of power and torque. Honda’s 3L V-6 – also a 10 Best Engines award winner for 2004 – surpasses some variants of Nissan’s VQ in specific output, but the VQ’s demonstrated flexibility means there are so many variants, in such a variety of vehicle applications, that the VQ’s power and specific output figures now are widely spaced.

When the VQ was enlarged to 3.5L in 2001, its story became one not only of power and refinement, but torque as well. In almost any iteration, Nissan’s VQ is a torque monster, and it generates a tidal wave of torque no other normally aspirated 6-cyl. can rival.

“The VQ absolutely hauls when you want it to,” says one Best Engines tester. “Still the best torque sensation all the way through the range.”

Indeed, one of the VQ’s most notable attributes – apart from its precise, linear and crisp throttle response – is its brawny torque production at just about any rpm. The VQ V-6 is the stoutest V-6 around – but it’s one of the most flexible, too. Regardless of what you ask of it, the VQ V-6 responds immediately. “There isn’t a hitch or hole anywhere in the powerband. The VQ V-6 generates so much torque it seems there’s always more than you need,” says another judge.

Subaru Fuji 2.5L DOHC turbocharged H-4
Three hundred horsepower. Three hundred pound-feet of torque. Thirty thousand dollars.

That’s probably enough to summate 90% of the winning formula for Fuji Heavy Industries Ltd.’s Subaru 2.5L turbocharged DOHC H-4. The only engine with a performance-per-dollar quotient like this is DaimlerChrysler’s 2.4L turbocharged DOHC 4-cyl., and it barely missed making the cut.

This is Subaru’s first-ever 10 Best Engines winner, and it’s not surprising given the company’s reputation for reliable, though usually unspectacular and unassuming powertrains. With the 2.5L turbocharged DOHC H-4, you can forget about that reputation: Subaru’s showing us why it’s won all those World Rally Championship trophies.

In the lightweight Impreza WRX STi, this engine exhibits truly violent performance. Sixty mph (97 km/h) arrives in 4.8 secs., so wave bye-bye to the Porsche 911 and stay neck-and-neck with Corvette. We told you this engine was strong.

The Subaru 2.5L turbocharged H-4’s most-direct competitor is the big-turboed 2L 4-cyl. that powers Mitsubishi’s own rally-car-for-the-street, the Lancer Evo-lution; the Lancer mill makes 271 hp and 273 lb.-ft. (370 Nm) of torque, for performance nearly identical to the STi’s. So why didn’t we even nominate the Evo engine? The reasoning is that if you’re going to be enamored of small 4-cyl. engines with lots of turbo boost, then why not go for the one with the best numbers? Moreover, Ward's judges believe the Subaru H-4 is smoother (thanks to its opposed-cylinder architecture), more flexible and more technically intriguing.

The turbocharged 2.5L DOHC H-4 marks Subaru’s first-ever use of variable-valve timing for its signature “boxer” opposed 4-cyl. Even if you resist the urge to stab the throttle to exploit the 300 lb.-ft. (407 Nm) of twist, the variable valve timing ensures the boxer 4-cyl. remains flexible and responsive. The intercooler for the wide-mouth turbo even sports its own gimmick: the driver has a switch that sprays the intercooler with water when that last kilowatt of power is required, presumably helping to cool the intercooler itself so that it can in turn deliver cooler intake air.

But this engine’s best trick is the one it’s bought for: otherworldy acceleration at almost any speed. Packing 120 hp/L, Subaru’s turbocharged 2.5L DOHC H-4 is one of the most exciting engines available in the U.S. at any price. Its relative affordability only underscores its brilliant performance and technical sophistication.

Toyota 1.5L DOHC I-4
When Ward's named Toyota Motor Corp.’s original hybrid-electric vehicle (HEV) powertrain as a 10 Best winner in 2001, nobody was sure if the thing even qualified as a competitor to standard internal-combustion engines. After all, HEV powertrains rely on an electric motor to in some way “aid” the IC engine; both engine and motor team to deliver torque to the drive wheels.

For 2004, we’re still not sure if Toyota’s super-intelligent Prius powertrain can – or should – be compared to standard IC engine-only drivelines. But we’re going out on a limb to say that the industry is going to see more HEV architectures – and we’d better decide to deal with them, because an HEV engineering priority always is going to be transparency to the driver and occupants.

Such is certainly the case with Toyota’s excellent second-generation HEV powertrain, Hybrid Synergy Drive. Apart from some of the antics the driver must perform to get the car moving, it’s not hard to imagine the uninitiated never knowing the Prius isn’t propelled by a standard IC-only driveline.

Little about the Prius’ stout 1.5L DOHC I-4 has changed for Hybrid Synergy Drive. It’s a low-revving, Atkinson-cycle (extended expansion ratio) 4-cyl. cleverly designed for low-friction, maximum-efficiency operation. It is uprated to 76 hp from the previous 70-hp peak, but torque remains the same unremarkable 82 lb.-ft. (111 Nm) at 4,200 rpm. The engine’s primary attribute, apart from the previously mentioned efficiency, seems to be unobtrusiveness – Prius buyers presumably would prefer it wasn’t there at all.

Meanwhile, the piddling torque output doesn’t really matter, because that’s where the Prius’ electric motor comes in. The AC motor is rated at 67 hp and 295 lb.-ft. (400 Nm) of torque, and all that extra twist is fully available between 1,200-1,540 rpm to augment the gasoline engine. So the Prius steps off with more authority than many moderately powerful IC-only vehicles.

But more important, that extra-strong motor is supplied power by a new 500-volt electrical system, nearly twice the old car’s 273 volts. In fact, the much higher system voltage is the Hybrid Synergy Drive’s real secret for producing mileage figures of 60 mpg (3.9L/100 km) city and 51 mpg (4.6L/100 km) highway – electricians know higher voltage always means higher efficiency. Toyota says the Prius’ nickel-metal hydride battery pack also is uprated; it’s 15% smaller, 25% lighter and has 35% greater output.

Finally, an optimized continuously variable transmission and what’s said to be one of the world’s most sophisticated energy-management systems ensure the two Prius motivators – the IC engine and the electric motor – are optimally employed, either separately or in tandem.

Hybrid Synergy Drive is a remarkable achievement. We know much of the powertrain community says it wouldn’t get encouragement from management for a midsize-vehicle powertrain that gets the car to 60 mph (97 km/h) in 11.3 seconds. But the Prius obviously isn’t meant for power-craving buyers.

We simply say, for what the Prius is meant to achieve, it does it remarkably well. And at press time, Toyota announced a hike in Prius production to meet rising U.S. demand. The company just hiked projected full-year sales to 47,000 units – a number that makes Prius look less like a curiosity.

And in 1995, Honda Motor Co. Ltd. had yet to launch its first V-6.