Ward's 10 Best Engines

These formidable engines, our six Best Engines evaluators believe, are — or, for repeat winners, remain — benchmark executions of engine design, innovation, manufacturing. They excel in a business that holds their "contribution" to the overall product in the highest regard and stand proud of the conventional.

For 2001’s installment, nothing about the Best Engines contest has changed. Each engine nominated by our six editors must stand up to every other nominated engine in a battle unsullied by the marketing-happy "category competition" that so devalues other industry awards. We don’t "sell" the Best Engines to anybody. These engines have to sell themselves to us.

Nominations are fettered by a few simple rules. The engine must be available in a regular-production vehicle available for sale in the current calendar or model year (i.e. no 2002-model engines can be tested in the 2000 calendar year). And the engine must be fitted in a passenger vehicle with a total "base" price of no more than $50,000; this includes all applicable costs such as gas-guzzler taxes, but excludes the increasingly annoying "delivery" charge.

We’ll warn longtime readers now: the time-honored 50-grand "cap" — which has held steady since the first Best Engines competition in 1995! — likely will increase next year. Never mind that the cost-cap has claimed its first true casualty, the brilliant Porsche Boxster S (a Best Engines winner last year that, by rule, would have automatically been nominated this year), by a piddling $200. No, we believe that if sales in calendar-2001 remain robust — that is, buyers continue to pay $40,000-plus for leaf spring-equipped SUVs — then we have to assume $50,000 no longer is enough to guarantee fitment of an outstanding engine.

Enjoy 2001’s 10 Best Engines. This year’s list represents the most "turnover" in the history of the award, and we think you’ll find some genuine surprises among the annointed.

And as always, the Ward’s 10 Best Engines will continue to be praised by customers, talked about by pundits, envied by competitors. o

— Bill Visnic

Audi AG

1.8L turbo DOHC I-4

Engine type: 1.8L turbocharged DOHC I-4

Displacement (cc): 1,781

Block/head material: cast iron/aluminum

Bore x stroke: 81 mm x 86.4 mm

Horsepower (SAE net): 170 @ 5,900 rpm

Torque: 166 lb.-ft. (225 Nm) @ 1,950 rpm

Specific output: 94 hp/L

Compression ratio: 9.3:1

Application tested: A4

Three years back, we liked the Volkswagen/Audi AG 1.8L turbocharged I-4 enough to name it one of the year’s 10 Best Engines. Then in ’99, it was barely nudged off the list in a mini-era of V-6 and V-8 infatuation that saw just one 4-cyl. earn a Best Engines title in two years of competition.

Since the 1.8L’s win back in ’98, the standard for 4-cyl. "entry level" engines has perked up — so much so that this engine’s original 150 hp now is delivered by any number of unassuming 4-pot power units. In fact, in ’99, the year this engine just missed a repeat win, we expressed disappointment that VW/Audi didn’t offer the higher horsepower that everybody — most notably aftermarket "chip" tuners — knows is just an electronic tweak away.

Well, Audi has noted the notched-up competitiveness of the entry luxury market, and for ’01 serves us the same delectable 5-valve-per-cylinder package, only with a most useful 20 extra horsepower.

Okay, it’s still not the 180 horses available from the same engine in Audi’s base TT coupe/roadster, but along with another 11 lb.-ft. (15 Nm) of torque, it’s enough to again make the Audi 1.8L one the most satisfying 4-cyl. engines you’ll ever use. And Audi probably reckons that the sport-oriented TT deserves some modicum of superiority over 4-door sedans, so it enjoys a slight horsepower advantage.

Although the 20-hp jump is immediately evident, the 1.8L’s wonderfully broad range of light-pressure-turbocharged torque is what delights most drivers.

"Sparkling midrange urge," notes one Ward’s tester. "This is my kind of engine," says another, who like us all, deeply appreciates the rewards of 94 hp per liter.

The presence of the Audi 1.8L demonstrates, to our minds, a clear divide regarding the recent state-of-the-art in turbocharging "philosophy." We continue to favor the light-pressure approach, in vogue with VW/Audi; meanwhile, the big-nozzle turbos now favored by AB Saab and Volvo Car Corp., although capable of producing great horsepower numbers, are not nearly as satisfying to use in everyday driving. Saab, in particular, has disappointed by largely abandoning its excellent light-pressure turbo efforts of the mid-’90s.

Sure, we’d like to see Audi do away with this engine’s iron block, and we’re not sure we agree with the marketing strategy of micro-managing horsepower ratings, but the fact remains this is a genuinely enjoyable engine: its NVH profile is outstanding and the 5-valve head design still is just exotic enough to stand apart from the 4-cyl. herd — an ideal entry engine for an upscale brand. o

Audi AG

2.7L Twin-Turbo DOHC V-6

Engine type: 2.7L 60° V-6

Displacement (cc): 2,671

Block/head material: cast iron/aluminum

Bore x stroke: 81 mm x 86.4 mm

Horsepower (SAE net): 250 @ 5,800 rpm

Torque: 258 lb.-ft. (350 Nm) @ 1,850 rpm

Specific output: 93 hp/L

Compression ratio: 9.3:1

Application tested: allroad quattro

If you’re surprised that Audi AG places two engines on this
year’s 10 Best Engines list, the accomplishment’s more notable
because both Audi winners are turbocharged.

With the scintillating 1.8L 4-cyl., Audi dials in just enough boost to make one forget that a tiny (at least for the U.S. market) 1.8L of displacement is the entire motivating force.

With this grunty 2.7L unit, though, the turbocharging accomplishes an entirely different mission: to make you forget that large prestige cars are supposed to have a V-8.

In fact, if you think prestige cars also are supposed to promote technology, then Audi brings more to the party with this V-6 than just about any V-8 you’d care to name: twin low-inertia turbochargers, one for each cylinder bank, are fed by individual intercoolers. Then there’s the trademark 5-valve-per-cylinder layout — now featured on every Audi engine. And both the valve timing and intake manifold feature variable activation. Throttling is fully electronic, helping to cut even further what little turbo lag may be evident; the allroad, however, did evidence a peculiar and highly annoying throttle tip-in hesitation.

But folks, this engine just storms. All 258 lb.-ft. (350 Nm) of torque is there for your exploitation by the time this V-6 measures off 1,850 rpm; never mind that in terms of specific output the 93 hp/L also places this unit firmly in the upper strata of current production engines. Pair that output with Audi’s ridiculously enjoyable 6-speed manual transmission and 60 mph (97 km/h) in an A6 sedan rolls up in 6 seconds flat.

Choose a gear — just about any of the available six will do — step on the minutely responsive throttle and that monstrous wave of torque blows the car past lesser-engined conveyances with majestic aplomb. With that sort of thrust, we don’t need no stinking V-8s!

Considering the contemporary state of V-8 development, you won’t get anywhere near the Audi 2.7L V-6’s techno package, anyway. Although we tested the 2.7L/6-speed driveline in the new (and quite good, by the way) A6-based allroad quasi-SUV, the "regular" A6 sedan/wagon also is available with Audi’s engaging 4.2L DOHC
V-8 — and the fact remains that we deeply prefer the twin-turbo V-6. To our way of thinking, the 2.7L twin-turbo V-6 is the perfect engine to promote what Audis are supposed to be. o

BMW AG

3L DOHC I-6

Engine type: 3L DOHC I-6

Displacement (cc): 2,979

Block/head material: aluminum/aluminum

Bore x stroke: 89.6 mm x 84 mm

Horsepower (SAE net): 225 @ 5,900 rpm

Torque: 214 lb.-ft. (290 Nm) @ 3,500 rpm

Specific output: 75 hp/L

Compression ratio: 10.2:1

Application tested: 530i

Not that there was anything wrong with BMW AG’s "old"
2.8L DOHC I-6. Just the contrary, as the now-defunct 2.8L
unit was perhaps the industry’s ultimate refinement of the inline 6-cyl. format.

But when it comes to engines, BMW can interpret the jungle drums better than anybody, and it could smell the competition closing in, circling: If BMW holds a unique — we say "hallowed" — position as the eminent employer of the I-6 layout, the competition could at least begin to chip away at that with better horsepower than Bavarians offer.

In fact, in last year’s "summation" of BMW’s 193-hp 2.8L I-6, we said: "190 hp ain’t enough anymore — even from BMW." We had an eye on any number of V-6s that produce substantially more power and torque — and the wonderful refinement of inline sixes only goes so far in the ever-escalating realm of powertrain competition.

So BMW made haste with a 3L version of the 2.8L engine for the ’01 model year. In the blur of a torque-enhancing stroke increase, BMW makes sure that its inline reigns supreme.

The new engine boasts a stroke of 89.6 mm, versus the previous 84 mm. The extra fifth of a liter of displacement that results, though, is hardly as inconsequential as the numbers might suggest, and the new 3L unit enjoys a serious fettling of camshaft profile, intake manifold and exhaust port shapes. What’s delivered is a hefty 32-hp increase over the 2.8L’s 193 hp and 8 more lb.-ft. (11 Nm) of torque.

Okay, that slight amount of torque hardly seems worth mentioning, but on the road, the effect is astonishing, as this new engine takes up from low rpm in a broad-shouldered manner the old 2.8L just couldn’t muster. And the double-VANOS infinitely variable valve timing assures there’s almost always a bootful of power at your disposal.

In one mighty thrust, BMW puts its "volume" engine back at the top — and sweeps aside challenges from upstarts like Lexus (215-hp I-6) and matches the power output of today’s generation of muscled-up V-6s, too. o

DaimlerChrysler AG

Mercedes 3.2L SOHC V-6

Engine type: 3.2L SOHC 90½ V-6

Displacement (cc): 3,199

Block/head material: aluminum/aluminum

Bore x stroke: 89.9 mm x 84 mm

Horsepower (SAE net): 215 @ 5,700 rpm

Torque: 221 ft.-lbs. (300 Nm) @ 3,000- 4,600 rpm

Specific output: 67 hp/L

Compression ratio: 10:1

Application tested: C320

These days, it’s hard to spit without hitting a pretty good V-6.
The V-6’s emergence as the engine best-suited for fitment
in North American vehicles is a combination of engineering and marketing dictates that aren’t likely to change anytime soon.

So it’s de facto there are plenty of solid V-6s out there — the market ordains a high order of development. But as we’ve said for the past four years, the Mercedes-Benz unit of DaimlerChrysler AG, when it set out to develop an entirely new range of modular V-6 (and later,
V-8) engines — the first V-6s in M-B history, no less — its drivetrain boffins weren’t about to engineer anything less than a benchmark.

Never mind that the modular manufacturing plan dictated that the V-6 engines adopt the 90-degree layout ideal for V-8s; a balance shaft, rotating at twice crankshaft speed, rectified the inherent internal-balance compromise involved with V-6s using a 90-degree vee angle.

Instead, the ingenious forethought was directed at the valvetrain, where Mercedes’ new modulars were developed to employ a SOHC, 3-valve-per-cylinder design that also sports twin spark plugs. It’s an optimized emissions-reducing layout with no quarter given to requisite power/torque targets.

For the Mercedes 3.2L SOHC V-6, making the Ward’s 10 Best Engines list for the fourth consecutive year seems only to confirm the validity of the trend toward modular engine development: Mercedes now employs this engine in five of its eight vehicle lines: The big-bucks S-, SL-, CL-Class cars are the only models not to employ this versatile powerplant.

The 3.2L V-6, for example, is new to the C-Class and SLK ranges and is positively invigorating in either model. Ward’s testers continue to be amazed at how adept Mercedes has become at tailoring this engine to a wide variety of applications — a subtle talent still too rare in powertrain engineering. The 3.2L V-6 is a grunty workhorse in the M-Class SUV, a coltish-but-refined delight in the all-new C-Class and positively snappish — as well as brilliantly intake- and exhaust-sound-optimized — in its new fitment for the SLK roadster.

Strangely, though, we’ve heard that this engine range may not enjoy the longevity typical of Mercedes powertrain designs. The SOHC, 3-valve layout, at any rate, may be sacrificed when the company adopts direct injection (DI). WAW is told that DI will preclude the use of three valves and twin sparkplugs because the injector to deliver fuel directly into the combustion chamber must be vertically oriented directly in the middle of each chamber.

For now, though, this 3.2L V-6 still represents the pinnacle of forward-thinking engine development. Whatever one believes the term "premium" should imply in relation to engines, the Mercedes 3.2L V-6 satisfies the description. It continues to be one of the finest V-6s available in volume production. o

Ford Motor Co.

5.4L TRITON SOHC V-8

Engine type: 5.4L SOHC 90½ V-8

Displacement (cc): 5,408

Block/head material: cast iron/aluminum

Bore x stroke: 90.2 mm x 105.7 mm

Horsepower (SAE net): 260 @ 4,500 rpm

Torque: 350 lb.-ft. (475 Nm) @ 2,500 rpm

Specific output: 48 hp/L

Compression ratio: 9:1

Application tested: F-150 Harley-Davidson Ed.

Every year now, they come. Every year now, Ford Motor Co.’s 5.4L Triton V-8 slaps ’em down.

Who? Why, those pesky truck-engine competitors, Pollyanish in their belief that they’ll best the Triton’s blend of trailer-tugging torque and righteous refinement.

In ’99, the 5.4L Triton fought off General Motors Corp.’s neat-but-narrowly focused 5.3L Vortec OHV V-8. Last year, it was the upset-minded Toyota Motor Corp. 4.7L i-Force DOHC V-8.

With truck engines, it’s all about comparisons. The Triton and the Vortec are close enough in displacement to be considered dead even. The Toyota V-8, however, gives up more than half a liter.

Once you’re into the serious workaday numbers, though, the 5.4L Triton continues to shine — despite the fact that both competing engines mentioned above are newer by a large margin.

The Triton’s 260 hp beats the Toyota 4.7L V-8 by 15 hp and lags the GM 5.3L V-8 by 25 hp. Mainly, though, that’s marketing; there’s little to choose between them in the power department.

People "drive" torque, we’re always told, and in that arena the Triton remains king, or whatever the name Triton implies. The 5.4L unit develops a wholesome 350 lb.-ft. (475 Nm) of torque at just 2,500 rpm, while the GM job needs 4,000 rpm to muster its 325 lb.-ft. (440 Nm) and the Toyota has to hit 3,400 rpm to deliver its 315 lb.-ft. (427 Nm). For truck engines, that’s all you have to know: the most torque available at the lowest rpm.

Normally, that would be more than half of the story, but the numbers don’t describe how artfully Ford Powertrain engineers developed the Triton to be the just-right bowl of porridge: not too trucky, not too refined. The GM V-8 needs more refinement, the Toyota, more truckiness.

The 5.4L Triton’s fourth year on the 10 Best Engines list — which doesn’t exactly reward foot-dragging when it comes to refinement — is testimony to the inherent "rightness" of the original design. A design which, we never tire of reminding you, represented an enormous leap of faith from Ford powertrain developers.

Oh, and did we mention the SUPERCHARGED version (which shares the "base" Triton’s award)? We would have, but we’re still catching our breath from that experience. The Ford SVT F-150 Lightning, powered by the supercharged 5.4L Triton, is the best truck in the business. And wait until the ’02 model year, when that unit jumps from today’s 360 hp to 380 hp. Even for a truck, that’s a lot of juice, hombre.o

General Motors Corp.

6.6L Duramax OHV V-8

Engine type: 6.6L 90½ turbodiesel V-8

Displacement (cc): 6,599

Block/head material: cast iron/aluminum

Bore x stroke: 103 mm x 99 mm

Horsepower (SAE net): 300 @ 3,100 rpm

Torque: 520 lb.-ft. (705 Nm) @ 1,800 rpm

Specific output: 45 hp/L

Compression ratio: 17.5:1

Application tested: GMC Sierra HD

Repeat after us, please:

Diesels stink. Diesels don’t rev. Diesels aren’t powerful. Diesels are low-tech.

Now, awaken from your stupor and get into the new century. While you were sleeping, diesels have changed, Jack. And changed for the better.

Europe’s on fire about the diesel. New, beautifully designed units are launched there almost monthly. As usual, the Europeans know something that we don’t.

Actually, GM knows. GM and its diesel-engine-expert affiliate Isuzu Motors Ltd., that is. They’ve teamed up to develop and build the all-new 6.6L Duramax, and not a neuron of the two companies’ best powertrain grey matter has been wasted.

First off, the Duramax replaces the cantankerous old 6.5L turbodiesel that GM’s had around since ’82 and really did represent just about everything BAD about diesels past.

The Duramax is as "180 degrees" as its gets.

There’s common-rail fuel delivery and direct (in-cylinder) injection of fuel, THE hot setup for diesels. The combo permits extremely high injection pressure, which translates to huge horsepower and low emissions. This thing doesn’t even need an exhaust catalyst, for heaven’s sake, and one tester swore that there’s almost no detectable diesel odor.

High horsepower? How’s 300 ponies at 3,100 rpm? And let’s not even talk torquey -- always a diesel strong suit. All right, we will: a magnificent 520 lb.-ft. (705 Nm!), auguring in to snap your neck at 1,800 rpm. We literally ripped out hunks of pavement from some poor businessman’s deteriorating parking lot as we accelerated away in glee.

Backing it up is an astonishing Allison Transmission division-made 5-speed automatic. Is this a good combo? It won Editor Winter’s respect — and he is no fan of the large pickup genus.

The Duramax is stuffed with so much good design we probably should just add a link here to GM Powertrain’s Website, ’cause we sure don’t have room to describe it all. Accept that the Duramax is a very efficient package, both smaller and lighter than competing turbodiesels, yet producing enormously more power and torque.

We love the way the turbo and its intercooler are snugged into the Duramax’s 90-degree vee. We love the gear-driven oil and water pumps. The nitride-hardened, forged-steel crank is beauty personified. And we love the awesome little cooling channels built into the piston crowns.

But mostly, we love 500-plus lb.-ft. of torque — combined with refinement that, frankly, is startling.

The Duramax changes the game. Let’s hope it starts a trend. o

Honda Motor Co. Ltd.

2L DOHC I-4

Engine type: 2L DOHC I-4

Displacement (cc): 1,997

Block/head material: aluminum/aluminum

Bore x stroke: 87 mm x 84 mm

Horsepower (SAE net): 240 @ 8,300 rpm

Torque: 153 lb.-ft. (207 Nm) @ 7,500 rpm

Specific output: 120 hp/L

Compression ratio: 11:1

Application tested: S2000

We tried several times to concoct a list of reasons not to like Honda Motor Co. Ltd.’s furious 2L DOHC I-4:

It’s only available in the S2000, a reasonably limited-purpose vehicle. It shrieks like hell unleashed, and it’s tough to welcome that after a grueling day of, say, licking your boss’s boots. And there’s really not much torque.

But those excuses evaporate after the first full-wrath trip to the 9,000-rpm redline, along the way passing that glorious VTEC (variable valve Timing and lift, Electronic Control) "changeover" point at around 6,000 revs. Every time you hit the VTEC change point and get on the "power" part of the cam — and we mean every time — you’re convinced you now are a hideously overpaid Formula One pilot/god. Bootlicking is but a distant memory.

Honda engines have a penchant for taking you "away" like that; almost all of our testers have owned a Honda at one time or another, and nary a one has anything but fond memories.

But the S2000 roadster’s 2L DOHC I-4 takes even Honda’s reputation to another plane. Honda engineers have told us, with an absolute humbleness, that 120 horsepower per liter doesn’t come easily for a production car; an everyday-reliable 8,300 rpm is required for the power peak, nearing the 9,000 rpm of the redline. Stratospheric output is okay for racing-car engines, they remind, because if the engine breaks, you put in another. It’s hard to imagine paying customers accepting that sort of "warranty" arrangement, though.

It’s not just the emotion that makes the Honda 2L I-4 a great engine. There’s a host of beautifully developed internal components such as the hardened connecting rods and special ceramic/carbon fiber cylinder liners that save space and weight.

Currently, the S2000’s 2L DOHC I-4 holds the record for production-engine specific output. We continue to applaud Honda for a no-compromise (if limited-purpose) high-performance 4-cyl. engine that already deserves a note of esteem in the history of the continuing development of the internal combustion engine. o

Nissan Motor Co. Ltd.

3L DOHC V-6

Engine type: 3L DOHC 60° V-6

Displacement (cc): 2,988

Block/head material: aluminum/aluminum

Bore x stroke: 93 mm x 73.3 mm

Horsepower (SAE net): 227 @ 6,400 rpm

Torque: 217 lb.-ft. (294 Nm) @ 4,000 rpm

Specific output: 76 hp/L

Compression ratio: 10:1

Application tested: Maxima SE (Anniversary)

What’s left to be said about the brilliant Nissan Motor Co. Ltd. "VQ" 3L DOHC V-6? It’s won a Ward’s 10 Best Engines award every year since its launch in 1995. And in winning yet again this year, the 3L VQ becomes the only engine to be a seven-time winner. Every year since we inaugurated the 10 Best Engines competition in 1995, the 3L VQ has won a place.

This engine design is working toward a decade in the market, yet it still soundly whips newer engines. Ward’s testers continue to apply precisely the same praise first used seven years ago when Nissan launched the VQ: "Absolutely uncanny lack of vibration," says one evaluator. "The throttle response is outstanding," effuses another, who adds, "This is unquestionably the best-revving V-6 ever."

We credit Nissan powertrain engineers for their prescience in attacking reciprocating mass in the VQ engine family: the "downstream" results of reducing the mass of many major internal reciprocating components are manifest — and pay off in rollicking rips through the rev range and supernatural smoothness and NVH properties.

We’ve said it before and we’ll say it again: There isn’t a better V-6 in all of automobiledom — regardless of price. The fact that the VQ is standard in two very affordable sedans, the Nissan Maxima and Infiniti I30, only seals the argument that the 3L VQ is one of the world’s finest engine designs. In fact, for Nissan’s engineers to develop such an extraordinary design for a series-production engine may be one of the company’s most underappreciated engineering triumphs.

Moreover, the VQ engine "family" is the foundation for just about every near-term new engine coming from Nissan. The most recent is the new, larger-displacement 3.5L V-6 that is unfortunately available, for now, only in the long-in-the-tooth Pathfinder/Infiniti QX4 sport-utes. All the great VQ-series attributes remain, but a hint of gruffness makes us wonder about the 3.5L’s ultimate refinement, although we must reserve final judgment until the engine can be evaluated in a more civilized package.

Soon to come is a VQ-based 4.5L V-8, to be launched in next year’s all-new Q45. Nissan engineers tell us to expect class-walloping horsepower.

We can scarcely wait. Nissan’s 3L VQ V-6 is a benchmark engine, through-and-through — and we expect no less from its future variants.o

Porsche AG

2.7L DOHC H-6

Engine type: 2.7L opposed H-6.

Displacement (cc): 2,687

Block/head material: aluminum/aluminum

Bore x stroke: 85.5 mm x 78 mm

Horsepower (SAE net): 217 @ 6,500 rpm

Torque: 192 lb.-ft. (260 Nm) @ 4,500 rpm

Specific output: 80 hp/L

Compression ratio: 11:1

Application tested: Boxster

Oh, what a difference two-tenths of a liter makes.

When we tested the "original" Porsche AG 2.5L opposed 6-cyl. engine in the all-new-for-’97 Boxster, we tipped a collective hat to the ingenious design but were unmoved — figuratively and literally — by the 2.5L "boxer" engine’s comparatively docile power/torque figures and its tinny NVH properties.

Then last year, the tantalizing 3.2L "S" version of the original 2.5L engine thrilled Best Engines judges: In one swipe of the engineering pen, the displacement increase solved all of the 2.5L engine’s deficits.

For ’01, unfortunately, our strict $50,000 price cap forced the Boxster S model into ineligibility. Meanwhile, though, at the same time last year that Porsche launched the 3.2L H-6, it also threw a displacement increase at the Boxster’s old 2.5L boxer engine, bringing it to 2.7L.

With the "S" engine ineligible, we tried the 2.7L engine. You see the result: another Best Engines winner for Porsche.

We’re more than slightly surprised that such a small displacement increase could make such an enormous difference. First, there’s now a rewarding tenor to the Boxster’s exhaust.

That extra two-tenths of a liter also addresses the old 2.5L engine’s shortcomings as a worthy premium sports car engine, i.e. lack of torque and power. Neither increase is mammoth — an extra 16 hp, for 217 total and another 4 lb.-ft. (5 Nm) of torque — but the on-the-road results are energizing.

Okay, we still believe this engine suffers from an inertia just off idle, but if one can tolerate that brief moment of terror as a Taurus out-drags you, the 2.7L H-6 soon resolves your initial disappointment. From roughly 2,500 rpm to redline, the acceleration and power delivery is bombastic.

More impressive is that sound, which wails from directly over your right shoulder. Sounds are difficult to describe, and even moreso with the Boxster’s 2.7L engine, because it’s a subtle blend of bass and brass, resonance and timbre and volume. The Boxster on the throttle has the intonation of a Le Mans racer heavily refined for street use.

And oh, that throt-tle’s a delight, too. We wonder how such feel — actual texture if you will — can be engineered into a unit that provides no mechanical connection with the engine itself.

That’s what Porsche’s 2.7L H-6 is about: feel and sound and power. The sort of "emotion" that’s made Porsche what it is. If you wonder why Porsches cost so much, be a passenger. Close your eyes. And listen. o

Toyota Motor Corp.

1.5L DOHC I-4 Hybrid

Engine type: 1.5L DOHC I-4

Displacement (cc): 1,497

Block/head material: aluminum/aluminum

Bore x stroke: 75 mm x 84.7 mm

Horsepower (SAE net): 70 @ 4,500 rpm

Torque: 82 lb.-ft. (111 Nm) @ 4,200 rpm

Specific output: 47 hp/L

Compression ratio: 13:1

Application tested: Prius

To save you searching the masthead at the front of the magazine, here’s my e-mail address: [email protected].

This service I provide to facilitate your letters of rage/praise/puzzlement/edification, because I know the problem already: the Toyota Prius hybrid-electric "system" isn’t really just an engine, so it’s unfair to judge it with these other "conventional" units.

There’s no easy answer, but we’ll supply this one: The holy grail of "alternative" powertrain development has been transparency to the consumer. What the buyer doesn’t know won’t hurt. If that’s the case, then we must assume developers of hybrids and other alternative-powered vehicles seek to mimic the performance and power delivery characteristics of gasoline IC engines.

And that, by most critical measures, the Prius hybrid drivetrain does.

Let’s get the hybrid business out of the way right now. The car employs a "parallel" arrangement, meaning that it can operate exclusively on the internal combustion engine, the permanent-magnet motor, or both in concert. The motor (motors are electric, engines are combustion) develops a maximum of 44 hp from 1,040 rpm to 5,600 rpm and a nice wallop of torque right off idle, as motors do, of 258 lb.-ft. (350 Nm) from 0 rpm to 400 rpm.

The car starts off on the electric motor. The IC engine runs most of the time, providing drive and generating power for the battery pack. We’re not going to say much more, because you can learn all about the intricacies of Prius operation elsewhere.

All right. The 1.5L DOHC I-4 features weight-optimized components like low-tension piston rings, a smaller-diameter crank and lower-load valve springs, all befitting its mission in life to operate in its most productive rpm range (which happens to be right around its 4,500 redline).

In addition, this neat little all-aluminum workhorse features Toy-ota’s slick infinitely variable valve timing system (VVTi) and a delicious design feature: the cylinders are slightly offset from the crankshaft so that when the prime combustion force occurs at top dead center, the piston is not angled from the crank, as it is in a typical IC engine. Toyota engineers say this helps to get the most from combustion and reduces friction as well. It just plain makes sense — and doesn’t cost anything.

Finally, the engine employs the Atkinson cycle to maximize thermal efficiency. Primarily, Atkin-son amounts to delayed opening of the exhaust valves, or what Toyota terms a "high expansion cycle." By delaying exhaust-valve opening, the engine also can employ smaller combustion chambers to derive maximum expansion ratio and put every last joule of fuel energy to work.

We could debate all day about how it all works and whether the Prius hybrid "system" is apples-to-apples with the rest of the engines on our list. But we’re going to stretch a little here, because the future holds the need for more interpretation of the term "engine."

For now, we’re telling you that not only does the Prius work well, it goes about its business transparently -- and that, as we’ve mentioned above, is a chief concern for "advanced" powertrains.

And Toyota’s 1.5L DOHC I-4 is a technical powerhouse, even if its output figures are modest. The Best Engines competition awards special points for technical advance, and right now, the Toyota Prius hybrid system and its specially designed engine peg the innovation meter. The fact that the Prius is eminently enjoyable, supremely refined and highly functional, is a bonus. o

Who was Tested, Who Was Bested

Our sometimes catty summaries for each Best Engines nominee, with a personal touch

Audi 1.8L turbocharged DOHC I-4

170 hp, 166 lb.-ft. (A4)

+ Love that little turbo puff.

– Too much hp manipulation among models.

= Eminem: Small. Big bark.

Audi 2.7L Twin-turbo DOHC V-6

250 hp, 258 lb.-ft. (allroad)

+ Storming torque, techno-weenie appeal.

–Startlingly poor fuel economy.

= Bette Midler: Belts it out with the best of ’em.

BMW 3L DOHC I-6

225 hp, 214 lb.-ft. (530i)

+No-excuses power increase.

– Hey, these things aren’t gettin’ any cheaper.

= Muhammed Ali: Floats like a butterfly, and you know the rest.

DaimlerChrysler Mercedes 2.6L SOHC V-6

168 hp, 177 lb.-ft. (C240)

+ Can hook it up to a 6-speed manual.

– A 2.6L engine should mean C260 on the badge.

= David Spade: Trying just a little too hard.

DaimlerChrysler Mercedes 3.2L SOHC V-6

215 hp, 221 lb.-ft. (C320)

+ More than meets the eye. Way more.

– The throttle-action god wants a word with you, Mercedes.

= Mark McGuire: Big hitter, snappy glove.

Ford 2L DOHC I-4

130 hp, 135 lb.-ft. (Focus)

+Agreeable enough, good NVH.

– Gotta have a manual to actually enjoy it.

= Gloria Estefan: Petite and punchy.

Ford/Lincoln 3.9L DOHC V-8

252 hp, 267 lb.-ft. (Lincoln LS)

+ Pretty cheap for a V-8 luxo-boat.

–Outgunned by a lot of good sixes.

= Barry White: Smooth but too slow.

Ford 5.4L SOHC V-8/5.4L supercharged

260 hp, 350 lb.-ft. Ford F-150 Harley Davidson

+ Hands out a butt-whippin’, truck style.

– Two valves is looking like two too few.

= Arnold Schwarzenegger: Powertrain ofchoice for traffic Terminators.

General Motors 2.2L DOHC I-4

135 hp, 142 lb.-ft. (Saturn LS200)

+ Quite smooth, sadly unnoticed.

–Specific output isn’t competitive.

= Susan Sarandon: Nice, but a little off- base.

General Motors 3L DOHC V-6

182 hp, 190 lb.-ft. (Saturn LS300)

+ Good mill for the money.

–Usually snoozing when the pedal is pressed.

= Dennis Miller: Works too hard at being laid-back.

General Motors 3.5L DOHC V-6

215 hp, 230 lb.-ft. (Intrigue)

+ Brawnier than import V-6s.

–Underachieving output, tech spec.

= Atlanta Braves: All the pieces, yet can’t win the big one.

General Motors 5.7L LS6 OHV V-8

385 hp, 385 lb.-ft. (Corvette Z06)

+ Omigod acceleration.

–Pushing this design’s retirement date.

= Tim (the tool man) Allen: No need to tweak this for more power.

General Motors 6.6L Duramax turbodiesel V-8

300 hp, 520 lb.-ft. (GMC Sierra HD)

+ Glorious refinement, hideous torque.

– Louder than the average bear.

= Mr. T: I pity the fool who don’t like diesel!

Honda 1.8L DOHC VTEC I-4

127 hp, 114 lb.-ft. (Civic EX)

+Four-cylinder nirvana.

–Nondescript to a fault.

= Bill Gates: Unassuming but successful.

Honda/Acura 1.8L VTEC DOHC I-4

195 hp, 130 lb.-ft.(Integra Type R)

+Rev-to-the-moon circus act.

–One-hundred-thirty lb.-ft? In America?

= Howard Stern: Entertaining but too much noise.

Honda 2L VTEC DOHC I-4 (S2000)

240 hp, 153 lb.-ft. (S2000)

+Normal-aspiration benchmark.

–Earmuffs should be standard equipment.

= Bruce Lee: Fists of Fury.

Honda/Acura 3.2L VTEC DOHC V-6

260 hp, 232 lb.-ft. (CL Type S)

+Satisfying personal cruise missile.

–"Numbers" don’t jibe with the "feel."

= Steven Seagal: Stretching to be some- thing it isn’t.

Honda/Acura 3.5L DOHC VTEC V-6

240 hp, 245 lb.-ft. (MDX)

+ New level of SUV engine refinement.

– We can’t totally forget it’s a minivan engine.

= Marlon Brando: Deserves respect without necessarily earning it.

Nissan 3L DOHC I-6

227 hp, 217 lb.-ft. (Maxima Anniv. Ed.)

+ World’s best throttle response.

–Three-foot-long gearshift lever.

= Conan the Barbarian: Still slays all competitors.

Nissan 3.5L DOHC V-6

250 hp, 250 lb.-ft. (Pathfinder)

+ More refined than SUV buyers deserve.

– Gritty around the edges. Pushing the displacement envelope?

= Lee Marvin: Tough but cleans up okay.

Porsche 2.7L DOHC H-6

217 hp, 192 lb.-ft. (Boxster)

+ Best soundtrack in the business.

– Have to live with that weak step-off.

= Steve McQueen: Shut up, Leonardo, and watch a real man act.

Toyota 1.5L DOHC I-4 hybrid

70 hp, 82 lb.-ft. (Prius)

+ Subtle, subtle.

– Hard acceleration is NOT part of the formula.

= Dr. Science: It knows way more than you do.

Toyota 1.8L DOHC I-4

138 hp, 125 lb.-ft. (MR2 Spyder)

+Refreshingly athletic.

– Not as smooth as you’d like.

= Britney Spears: Too energetic to be a one- hit wonder.

Toyota 2L DOHC I-4

148 hp, 142 lb.-ft. (RAV4)

+ Gives the shirt off its back.

– Still masquerading for a V-6.

= Beaver Cleaver after a summer in the weight room.

Toyota/Lexus 3L DOHC I-6

215 hp, 218 lb.-ft. (IS300)

+ Never met an inline six we didn’t like.

– Please FedEx us 40 hp, 6-speed manual.

= Buffy the 3-Series Slayer: On a mission.

Toyota/Lexus 4.3L DOHC V-8

300 hp, 325 lb.-ft. (GS 430)

+ Insert: iron-fist/velvet glove cliché.

– Still a touch too clinical.

= Frank Sinatra: Class act that’ll kick your butt if you ask for it.

Volvo 2.3L turbocharged DOHC I-5

247 hp, 243 lb.-ft. (S60 T5)

+ Can’t deny that’s a lot of ponies.

–Driveability isn’t a strong suit.

=Braveheart: Subtle as a battle axe.