By on July 28, 2015

Mercedes-Benz CLA45 AMG. Photo courtesy Autoblog

It was nearly 15 years ago that Honda was touting their magic number — 118.5 hp/L. This was the specific output for the U.S.-spec Honda S2000 powered by a high-strung, 237-horsepower, 2-liter engine and it was a marvel of engineering, trumping the Viper and many other more expensive machines.

Fast forward to today and there are only a few naturally aspirated vehicles that top Honda’s claim to fame, but many that easily beat it with some form of forced induction. Yet, even with this plethora of new high-output, small-displacement engines, the average specific output of gasoline and flex fuel vehicles in the United States is still below the record set by Honda back in 1999.

Thanks to data provided by iSeeCars, we came up with some interesting data when it comes to specific output for 2015 model year vehicles.

For one, the Mercedes-AMG CLA45 (pictured above) and the GLA45 with which it shares its turbocharged, 2-liter, four-cylinder engine are the top performers with specific outputs of 177.5 hp/L. It should be no surprise that turbocharged engines dominate the top 100 engines ranked by specific output, but there are some exceptions. The top naturally aspirated mill in the mix — the 597-hp, 4.5-liter V-8 in the Ferrari 458 Speciale — has a specific output of 132.7 hp/L. Porsche’s 911 GT3 is solidly mid-pack with 125 hp/L.

On the other end of the scale, trucks score quite low on the specific output meter, as the Ford F-350 equipped with a 316-hp, 6.2-liter V-8 struggles to make 51 hp/L. The lower output may not be representative of a behind-the-times engine, but rather it could be characteristic of their applications. Trucks need torque more than horsepower to do the work they were built to do.

Overall, the average for specific output for non-hybrid, gasoline and flex fuel engines sits at 93.3 hp/L, just 25.2 hp/L shy of the naturally aspirated benchmark set by the Honda S2000. However, as more automakers downsize their engines and boost output with turbocharging, we may just see the overall average crest this high-water mark in the coming years.

Below is a list of the top and bottom 10 vehicles available on the retail market for the 2015 model year ranked by specific output.

Top 10

  1. Mercedes-AMG CLA45/GLA45
    2-liter turbocharged I-4, 355 horsepower
    177.5 hp/L
  2. McLaren 650S Coupe/Spider
    3.8-liter twin-turbocharged V-8, 641 horsepower
    168.7 hp/L
  3. Nissan GT-R NISMO
    3.8-liter twin-turbocharged V-6, 600 horsepower
    157.9 hp/L
  4. Volvo S60/XC60
    2-liter twincharged I-4, 302 horsepower
    151.0 hp/L
  5. Porsche 911 Turbo S
    3.8-liter twin-turbocharged H-6, 560 horsepower
    147.4 hp/L
  6. Audi S3/Volkswagen Golf R
    2-liter turbocharged I-4, 292 horsepower
    146.0 hp/L
  7. Mitsubishi Lancer Evolution
    2-liter turbocharged I-4, 291 horsepower
    145.5 hp/L
  8. Nissan GT-R
    3.8-liter twin-turbocharged V-6, 545 horsepower
    143.4 hp/L
  9. Bentley Continental GT3-R
    4-liter twin-turbocharged V-8, 572 horsepower
    143 hp/L
  10. Ferrari California T
    3.9-liter twin-turbocharged V-8, 553 horsepower
    141.8 hp/L

Bottom 10

  1. Ford F-350 Super Duty
    6.2-liter V-8, 316 horsepower
    51.0 hp/L
  2. Chevrolet Silverado/GMC Sierra 3500HD
    6-liter V-8, 322 horsepower
    53.7 hp/L
  3. Nissan Titan/NV Cargo/NV Passenger/Armada
    5.6-liter V-8, 317 horsepower
    56.6 hp/L
  4. Chevrolet Express/GMC Savana (Cargo/Passenger/Cutaway)
    6-liter V-8, 342 horsepower
    57.0 hp/L
  5. Volkswagen Jetta
    2-liter I-4, 115 horsepower
    57.5 hp/L
  6. Ram Chassis 3500
    6.4-liter V-8, 370 horsepower
    57.8 hp/L
  7. Toyota Tacoma
    2.7-liter I-4, 159 horsepower
    58.9 hp/L
  8. Toyota Tacoma
    4-liter V-6, 236 horsepower
    59.0 hp/L
  9. Chevrolet Express/GMC Savana (Cargo/Passenger/Cutaway)
    4.8-liter V-8, 285 horsepower
    59.4 hp/L
  10. Chevrolet Silverado/GMC Sierra 2500HD/3500HD
    6-liter V-8, 360 horsepower
    60.0 hp/L
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72 Comments on “Average Gas Engine Specific Output Isn’t Quite 100 HP/L, Yet...”


  • avatar
    mike1dog

    All I can say is VW should be ashamed of themselves.

    • 0 avatar
      qfrog

      Seriously? I like to beat on VW/Audi but you’re saying to be ashamed of the leftovers engine which is served with a tree trunk rear axle to make the car cheap enough to meet the poverty spec for US buyers to bite. You know what is great about the early 2.0 8v engines? The ABA code engine… the early ones had forged cranks. I use one of those early forged cranks in my 2008cc 20v turbo which is a bored and stroked AEB 1.8T. Oh and the blocks from those ABA 2.0 engines can be used to make big power too, they are a tall deck variant of the early 1.8T so you can stroke the engine and keep a reasonable rod/stroke ratio to allow the engine to rev safely. When you want more than two liters, the taller block becomes necessary. Using parts from a 115hp cross flow 8v engine to develop over 200hp per liter is pretty much standard fare when following some very effective engine recipes. As for the 8v you think VW should be ashamed of, maybe the car has some other features or better functions because the mfg went so cheap on the engine. Clearly hp/L performance was not the objective.

      • 0 avatar
        Shinoda is my middle name

        Spot on froggie….horsepower is a continuum….not every engine for every vehicle application ‘needs’ to meet the highest HP standard, even if in its basic structure a particular engine design may be capable of it. There are hundreds of millions of different drivers doing different things with their vehicles…horsepower is but one criteria that defines a vehicles capability.

    • 0 avatar
      carlisimo

      That’s why they call it the 2.slow.

  • avatar
    twotone

    Normally aspirated engines with 100+ HP/l are very impressive. Forced induction, not so much. Even the bottom ten on the list are not bad when compared with the big block V8s of the 1970’s that were making 25 HP/l, or less.

    • 0 avatar
      stuki

      The bottom list is all truck engines. Which renders the comparison about as meaningful as comparing motorcycle engines to 2 stroke container ship ones along some arbitrary metric.

      Truck engines, when used for their purpose, are generally cooling limited. Further concentrating heat stresses is just plain silly. When pulling a load up a hill on a hot day, engine management limits even their “low” output further, to prevent overheating.

      If any of the editors have reasonably easy access to the data, I would like to see a comparison of total engine weight per peak HP, between the newer blown engines, and equally modern NA ones. That would actually mean something.

      • 0 avatar
        DC Bruce

        Actually, a number of the truck engines identified produce more horsepower in their 3/4 ton (“2500”) application than their 1-ton (“3500”) application, rendering the comparison even more pointless. If memory serves, the 6.4 liter Chrysler engine in the RAM 2500 is rated at 410 hp, the 6.0 Chevy engine in the Silverado/Sierra 2500 is rated at 360 and the 6.2 liter Ford engine in the F-250 is rated at 375 hp.

        • 0 avatar
          stuki

          And, truck engines’ commercial (chassis etc.) ratings are lower still.

          And then, for genuinely continuous duty, as when marinized or powering farm equipment, pumps and generators, they (diesels, though) are generally rated much lower again.

  • avatar
    djsyndrome

    The old Toyota 2ZZ (early 2000s Celica/Matrix/Corolla) made 180HP (pre-SAE recalibration) out of 1.8L, for an even 100hp/L. IIRC Lotus was able to stretch even a bit more out of this motor.

    I’d like to see a top-10 list of naturally aspirated engines. I can only think of a few off the top of my head that will meet the 100hp/L mark.

    • 0 avatar

      We might be able to do this later on!

      • 0 avatar
        DenverMike

        I agree it’s pointless to consider turbo engines. They can be tuned to whatever the OEM feels is long-term reliable and the rest of the car can handle. And it’s rather pointless to not consider the torque output.

        The dyno gives a torque figure, not “hp”. Hp is calculated by where in the rev band “peak torque” is reached. Really misleading for the customer. The Windsor 302 V8 has 225 hp, but 300 lbs/ft of torque. The s2000 has all of 162 lbs/ft of torque. So it’s all about how soon or late “peak torque’ hits.

        So it’s kind of silly to be impressed by big hp figures without knowing what’s the “torque”.

    • 0 avatar
      CoreyDL

      I can’t think of many, and the Nissan VQ’s don’t make it unless you’re using a hybrid.

    • 0 avatar
      Demetri

      Several Honda engines make that mark. B16 engine in the Del Sol VTEC and 99-00 Civic Si made 160 out of 1.6L. K20 in the RSX Type S made 210 from 2.0L. Integra Type R, made 195 from 1.8L. There were also variations in Japan that made even more HP. They had the Civic Type R with a B16 making 180, an RSX Type R making 220, and also a Prelude Type S/SiR making 220 from 2.2L.

      The FR-S/BRZ, E46 and E90 BMW M3 and Mitsubishi FTO also come to mind, and if you want to throw Wankels in there too Mazda obviously blew that mark away with the Renesis, and even the ones in the FC RX-7 made more than 1hp/liter.

      • 0 avatar
        DenverMike

        What’s interesting about the E90 M3 was its 295 lbs/ft of torque, to its 414 hp. It could keep up with the 412 hp 5.0 Mustang only because of the M3’s way more aggressive gearing. Otherwise it would’ve been hosed. But the V8 M3 was a gas $ucker, down there with the F-150 of its day. The 4×4 crew cab F-150.

  • avatar
    SomeGuy

    I’m not too concerned with the Bottom 10 because they are trucks (why are you in this list VW Jetta??). Trucks don’t live and die by HP like cars do, so again not surprised.

    Cool list though. I knew the AMG motor had some crazy specs, but didn’t realize it was #1!

  • avatar
    rpn453

    It’s not racing, and there are no rules controlling allowable displacement (where logic rules in that regard, anyway), so these numbers are irrelevant.

    Output per unit of engine mass would be more interesting. Output per unit of external engine volume would be even more so, for packaging considerations.

    Efficiency, responsiveness, and the power/torque curve are the important engine performance factors for street vehicles.

    • 0 avatar
      qfrog

      I think the Honda F and K engines will probably do well in output for weight.

    • 0 avatar
      nels0300

      Yes, output per unit of engine mass/volume while considering efficiency and responsiveness is what it’s really about.

      Given that criteria, I think the Corvette has always been pretty impressive. The LS motor is compact and light (vs OHC engines), very powerful, and capable of 30 mpg on the highway. Say what you want about pushrods, but this motor gets it done.

    • 0 avatar
      j3studio

      That would be correct. I have never gotten this hp/liter or hp/cubic inch thing be used as an end all/be all. Mass is what matters.

    • 0 avatar
      CJinSD

      Back when people weren’t silly enough to fall for market manipulation on a scale of the new CAFE, I recall seeing a metric called gal/hphr, which measures fuel used per horsepower hour produced. This is the real measure of an engine’s efficiency. I recall that the Buick 3800 V6 was one of the top engines of its time for this metric, and the efficiency of cars equipped with the 3800 reflected it.

    • 0 avatar
      heavy handle

      The metric you are looking for is Brake Specific Fuel Consumption (BSFC). That’s basically HP per gallon of gas.

      • 0 avatar
        stuki

        Does anyone rate car engines along that metric? I’m assuming there would be variability depending on load, external conditions etc. Seeing pretty detailed measurements of that metric, would be really cool. But perhaps a bit too revealing for engine designers….

        • 0 avatar
          wmba

          The two best gas engines are the Prius and Accord Hybrid engines at about 212 grams/kWh BSFC at optimum rpm and load. Both Atkinson cycle. No turbo engine is going to match a normally aspirated engine at this game, which is why the switchover to turbo engines has baffled me.

          • 0 avatar
            stuki

            Interesting. Is the efficiency of those engines unusually peaky, hence only useful when paired with an electric co-drivetrain? Wrt engine speed, load or both?

            Highly optimized marine engines can be very efficient at a very narrow rpm and optimal loading, then once outside that narrow window, degenerate into almost the equivalent of burning diesel just for the fun of producing soot. I’m assuming the same holds for the engines powering diesel electric vessels.

        • 0 avatar
          ECarGuru

          The BSFC isn’t a number, it’s a graph. There will be a peak value, but it’s actually a 3d graph like an elevation map. It compares loads and rpm’s and from my understanding is typically only shown at operating temperature.

          Interestingly enough a lot of them are in “grams of fuel per hour per newtonmeter times RPM” or silly things that need a thousand conversions to make legible.

  • avatar
    RideHeight

    Yay, power on to that next stoplight!

    I’m more concerned about not suffering the potholes between them. What is the ultimate USDM vehicle for *that*?

    Dat wut *I* enthooz about!

  • avatar
    nels0300

    High horsepower per liter from a naturally aspirated engine isn’t THAT impressive.

    It just needs to rev. So you make an engine that can breath really well and make it out of stuff strong enough that the engine doesn’t rip itself apart at high RPMs.

    I had both a 1992 VTEC Integra and a 1991 LX 5.0L Mustang back in the day. The Integra had a much higher horsepower per liter than the Mustang, but the Mustang felt 100 times more powerful and would’ve stomped the $hit out of the Integra. Both fun cars, but the HP/liter comparison doesn’t tell you anything.

    Same deal with a rotary vs. a GM LS engine. The LS engine is a better engine all day long despite having a lower hp/liter.

    • 0 avatar
      JMII

      This is because the 5.0 Ford made huge TQ compared to the VTEC. I was once a Honda fan then I drove a turbo VW, that converted me. The TQ makes all the difference. The VW felt so much faster (butt dyno). My Hondas would only move once you rev’ed them up. Sure it was fun, but if you turned the A/C on it killed the little Honda mills. The VW powered on nicely regardless of accessories load or RPM.

      • 0 avatar
        nels0300

        Yeah, the Integra had something like 110 lb-ft at 7000 rpm and the Mustang had 300 lb-ft at 3000 rpm.

        And yeah, the AC killed the Acura. I could have 3 friends in the Mustang with the AC on and it still hauled ass.

    • 0 avatar
      sportyaccordy

      On the street, midrange is king. I love the engineering behind engines like the B18C and K20A, but in real life I can’t stand driving them. I don’t like having to wind an engine out just to keep up with traffic, and often those high revving motors are coupled with super short gearing that makes things even weirder. Took me a long time (and experience with big/turbo motors) to snap out of that mindset. HP/L gives you all the speed with none of its sensations. It’s kind of like a fast car in a video game.

  • avatar
    skitter

    All of the trucks with 300hp have an immense amount of power, full stop. 270hp is enough to drive a tractor trailer at 70mph on flat ground, so it is, as with Rolls-Royce, ‘sufficient’ for civilian loads, even in the mountains. Larger displacement and lower power generally mean lower cylinder pressures, which mean lower stresses on bigger pistons and rods and crankshafts, which plays a big part in these trucks actively doing real work for hundreds of thousands of miles. The Ecoboost F-150 isn’t a radical experiment because it’s turbocharged. There are plenty of turbodiesels lumbering around with phone-number odometers. The longevity question with the Ecoboost comes from being small displacement — fewer, smaller parts doing the same amount of work — and therefore more highly stressed. A 6-liter V8 with 300hp that will run for hundreds of thousands of miles is just as amazing as the 2.0 V6 Ghibli Cup with 165hp per liter.

    • 0 avatar
      jmo

      “smaller parts doing the same amount of work”

      You theory then, is that Ford doesn’t adjust for that? When it builds a NA motor it builds the parts far sturdier than they need to be. But, when it builds a turbo engine they engineer the parts to a lower standard?

      • 0 avatar
        skitter

        I’m sure the Ecoboost rods, bearings, and crankshaft are very well engineered. But there are fewer of them, the piston area is smaller, and the cylinder pressures are higher.

        • 0 avatar
          jmo

          ” But there are fewer of them, the piston area is smaller, and the cylinder pressures are higher.”

          Right, but presumably they compensate by using various different types of steel. So, in a NA engine they might use en16 but in a turbo they use say en19?

        • 0 avatar
          jmo

          Here is a list of differences between a Ford NA motor and a ford turbo motor:

          Head Gasket
          The head gasket on the turbo IDI has a heavier fire ring and armor wrap to withstand higher firing pressures and combustion temperature.

          Connection Rod
          To provide additional strength for the increased horsepower output, the connecting rod has a large wrist pin bore and large wrist pin bushing. The pin bore diametere has been increased from 1.1108″ to 1.3086″ which is a 17% increase

          Pistion Pin
          The piston pin for the turbo IDI is larger in diameter. 1.308″ vs 1.110″ which is a 17% increase in diameter.

          Anodized Piston Head
          The piston head for the IDI turbo is anodized. It makes it more resistant to crackes caused by the increased firing pressures and combustion tempseratures associated with turbocharging.

          Pistion Rings Keyston Design
          The top and intermediate ring on the IDI turbo is keystone designed. Keystone rings are a premium heavy duty diesel feature that complements turbocharging which improves ring life and decreses the potential for ring sticking

          Exhaust Valve
          The exhaust valve used in the IDI turbo is made of inconel alloy and the valve stem is full chrome plated. Inconel alloy provides greater corrosion resistance and fatigue strength at the higher temperatures of the turbocharged engine. The Turbo exhaust valve can be identified by the dimple and part number on the head of the vlave. The NA has a smooth surface. Both valves have the same 37.5* face angle.

    • 0 avatar
      319583076

      Reliability, or endurance, of stressed parts is fundamentally related to the ratio of working stress to yield stress as well as whether or not the stresses in a given part reverse direction. In any case, stricter quality control on materials and parts (reduced variance) can very well produce higher stressed parts with reliability matching that of lower stressed parts – provided the engineers and manufacturers have done their work correctly.

    • 0 avatar
      sportyaccordy

      Diesel engines run compression ignition and crazy boost levels… they see far greater cylinder pressures than gas engines. I’m certain they also have much higher average HP too.

      I agree though that the smaller displacement was a bad idea. My rule of thumb for turbocharging engines is the displacement should be ~.75cc/lb of car. Many of Ford’s Ecoboost engines are like less than .50cc/lb of car. So it’s no wonder they don’t make good on their promises. They should have just added DI and turbocharging to the old engines.

    • 0 avatar
      wmba

      “Larger displacement and lower power generally mean lower cylinder pressures, which mean lower stresses on bigger pistons and rods and crankshafts.”

      True. And also higher friction losses for the same output due to more bearing rubbing area and more linear feet of piston ring.

      It’s no surprise to find that all the high-power, over the road diesel engines for big rigs have usually only 6 cylinders and overhead cam four valve heads. For friction reduction compared to pushrod V8’s. Not many V8’s left – two cylinders’ worth of friction – gone. This is where you find no-bullsh*t engineering these days.

      By that big diesel metric, the old two valve gas pushrod V8 is out-of-date. Volumetric efficiency isn’t great, high valve-spring pressures create high friction at low rpm. But the apologizers will still be at it 75 years from now and rattling on about Corvette and Hemi engines. If they were that wonderful, all new GM and FCA non V8 engines would be pushrod.

      At least Ford got out of that old mentality decades ago.

  • avatar
    schmitt trigger

    That is correct. Tradeoff of longevity against hp vs displacement.

    For instance a GE 7FDL-16, 4500HP turbocharged locomotive engine, has an specific output of about 20.5 hp/lt. But it will last a million miles.

  • avatar
    carlisimo

    “Trucks need torque more than horsepower to do the work they were built to do.”

    What you want in a truck is a lot of power at low revs, which means needing a lot of torque at those low revs. At 3,000 rpm, an S2000 (AP1) makes about 60 hp at the wheels. An F-150 is closer to 150 hp (I think that’s at the crankshaft – I’m just googling dynographs). The S2000 driver is okay with that because he isn’t going to spend much time at or below 3,000 rpm.

    The F-150’s torque curve isn’t as flat as I thought it’d be… it doesn’t look fantastic at 2,500 rpm.

  • avatar
    eggsalad

    I used to drive redblock Volvos, non-turbo. About 50hp/liter.

    Won’t win any races, except one: 0-500,000 miles, without rebuild.

    I suspect EcoBoost, et al engines will need to be replaced (not rebuildable) by 250k.

  • avatar

    I think of torque as having to do with acceleration, and HP as having to do with the ability to maintain a certain speed against various forces, such as gravity on an incline. (My then 8 year old, 91k 1962 Ford Falcon had low HP, and thus couldn’t keep climbing in the Rockies in third gear.) Thus, I have long wondered why torque isn’t the number focused on the most.

    Am I correct about torque v HP, and can anyone explain why torque isn’t focused on more than HP?

    • 0 avatar
      rpn453

      Torque at the wheels is what relates directly to acceleration. The ability to generate that torque is better described by the peak horsepower rating of the engine than the peak torque rating, provided the gearing allows the engine to use that horsepower.

      However, the torque rating probably is the more important number for most drivers, who are rarely using peak power. Rather, they rely on the lower end of the torque curve for the vast majority of their acceleration events.

      I think torque isn’t focused on as much because that’s not what puts up the test numbers. The effect on driveability is harder to describe, and depends so much on engine and transmission responsiveness that peak torque numbers alone aren’t necessarily all that valuable to most drivers either.

      • 0 avatar
        See 7 up

        You both are confusing terms
        For acceleration and maintaining speed, hp is all that matters. It’s a measure of work.
        Higher hp will result in faster acceleration and greater sustain load (speed), period.

        Torque is a measured force produced by an engine. The speed at which this is measured yields hp. Torque at zero speed with result in zero acceleration.

        This issue with ICE’s is that that aren’t constant power devices and must be used across a rev range. As such people like “torquey” engines because they are higher hp engines at lower rpm.
        Torquey engines also tend to have more “area under the curve” and as such will be faster since they have more average hp over a given rev range in a gear

        Long story short, when people say they like “torque” what they mean is that they like higher relative hp at lower rpms. You don’t feel torque. You feel acceleration and acceleration is provided by hp. If you could make a 100 ft-lb engine transmit power at 20000 rpm via a theoretical gearbox, it would be faster than a 250 lb-ft engine at 5000 rpm even though one is torquier. Such a constant engine and transmission don’t exist though

        • 0 avatar
          rpn453

          Please, explain what terms I confused so I don’t do it again.

          “Torque at zero speed (will) result in zero acceleration.”

          What does that mean? That you have to already be moving to accelerate? Torque = (Moment of Inertia) x (Angular Acceleration), whether you’re starting from rest or not.

          • 0 avatar
            See 7 up

            Torque is a force, a force can result in acceleration (F=MA) but for one to do any work (movement) one must keep that force up (at speed) over whatever work period desired (be that a 1/4 mile drag or a cross country road trip).

            I stated you were confusing terms because torque in and of itself does nothing. Power is the measure of work and is the only thing that does anything. They are obviously mathematically related and derived to the moment, torque does cause infinitesimal acceleration (as your equation shows). And you won’t have hp without torque, nor will you have acceleration without torque, but you won’t really go anywhere without hp.
            But I think you know all of this very well and rereading your original comment makes that clear (“the ability to generate that torque” = hp)

            When I say torque at zero speed causes zero acceleration – think of this example. Torquing a nut to 50 lb-ft that has already been torqued to 100 lb-ft. You are providing torque, but get no acceleration (your equation again shows this). If you exceed the 100 lb-ft, you get a tiny moment of acceleration, but it will result in nothing unless you can provide power (force over distance – torque over angular movement).

            Apologies if I hurt any feelings. Honestly, I think the best answer to all of this is “look at a torque curve”. That will tell you more about your engine that any peak number, tq or hp.

          • 0 avatar
            rpn453

            Determine the rate of work all you want, but it’s still the sustained torque doing that work and the acceleration comes directly from that.

            Yes, there is no motion when the sum of moments is zero. But the sum of moments is nowhere near zero when a vehicle is putting down many thousands of lb-ft of torque at the wheels all the way through first gear.

            I’m not disagreeing with the fundamentals of what you’re saying, but if you want to try to pick apart my attempt at an explanation then I’ll do the same to you. Maybe my comment was difficult to interpret and provided no value. However, I believe it is technically correct and needs no rectification.

            This has always been a terrible subject for discussion. It was during late night study sessions in school, and it is now on forums. Even when everybody involved already understands the basics, we can always perceive faults in semantics or logic and find ways to challenge any representations of these mechanically simple concepts that are difficult to describe concisely.

            The irony in this is that I was always the one arguing that power is what really matters. I just thought I might be able to relate how gear reduction allows that power to be applied as meaningful torque at the wheels for the purpose of acceleration. Apparently I failed.

          • 0 avatar
            rpn453

            Here’s an interesting example for anyone still pondering this stuff:

            The Tesla Model S P85D isn’t producing any power the moment it launches, and only 150 hp at 10 mph, on its way to a 3.3 second 0-60 time. That’s a lot of power for such a low speed, but it doesn’t sound like it. To me, it’s the 6600 lb-ft of torque at the wheels that really describes what’s happening. It never even quite reaches its peak output of 691 hp during that run.

            Regardless, the torque and power numbers are directly related using simple equations and interchangeable as descriptors of the motor’s output.

    • 0 avatar
      carlisimo

      Power and torque are directly related: power is torque (the amount of twisting force per engine cycle) times engine speed (revs). If an engine makes the same torque at 2,000 rpm as at 4,000 rpm, then it’ll make twice as much power at 4,000 rpm than at 2,000. You can’t have one without the other

      The problem is that people like to talk in terms of peak torque and peak power. Those don’t tell you much without additional information. What you really want is the power generated at the rpm level that you will actually use – that’s what you feel. For hauling or even just driving around town, you want a healthy amount of power at 1,500 – 3,000 rpm. That means having a healthy amount of torque at those rpm. For racing, you can sacrifice torque/power in that range and focus on having them above 5,000 rpm. The best way to find out what you’ve got is by looking at dynometer graphs, e.g.:
      http://www.tune86.com/sites/default/files/pictures_photos/2012/04/scion-frs-dyno.jpg

      Here, the solid line is torque vs. revs, the dotted line is power vs. revs. They should be separate graphs with different vertical axes, but they’re usually scaled and superimposed so you can see the relationship between the two. If the torque curve were flat, the power curve would be an ascending line. The FR-S’s engine has a torque deficiency at 4,000 rpm, so power doesn’t increase as much as usual in that range. Most torque curves have a shallow peak in the midrange and then drop off at high rpm. Cam-changing VTEC allowed Honda to give its racier engines two torque peaks (e.g. http://tinyurl.com/om6obbv ), one at 3,000 rpm for normal driving and another above 6,000 rpm. Now there are fancier ways of trying to improve torque everywhere in the rev range.

      Hope that helps.

  • avatar
    danio3834

    Meh, it’s a useless metric.

    • 0 avatar
      pbr

      Eh, might actually serve as guidance on what cars to stay away from … not that anyone buying anything out of that Top 10 is concerned with cost or longevity. But I have the opinion that those in the Bottom 10 have a rep of running a lot longer than you want them to.

      HOWever, since this is a measurebating post … if you want to talk HP/L, let’s talk motorcycles. New R6, anyone? From memory, 140 HP/600 cc. 233 HP/L, in round numbers. Naturally aspirated.

  • avatar
    Rod Panhard

    Consarn it! You young whippersnappers don’t know how good you have it. Why, back in my day, getting 100+ horsepower out of a 2-liter engine fresh from the factory was a big deal. Then came the early 1970s and Mom’s Cutlass could barely muster 140 horsepower out of a 5.7 liter V8 that got 15 mpg.

    That was it. We’d all thought the whole world had gone down the toilet, and told everyone on our CB radios. We’re living in the Golden Age of the Automobile right now.

    We might not have the flashy tailfins or opera windows or landau roofs, or waterfall grilles, or Dagmar bumpers, but at least our cars run when we turn the key.

    It’s too bad about them airbags, though, but I warned ’em!

  • avatar
    APaGttH

    The only low HP engines I’d kick out of bed in that list is the VAG two-oh slow and the GM 4.8L V8. Never been a fan of the GM 4.8 and the VAG 2.0 is just an awful engine.

  • avatar
    piro

    The UK market Evos must be somewhere up the top of all time, such as the Evo X FQ-400 and even the more limited FQ-440.

    Sure, they’re basically tuned cars, but they were available to buy from a dealer, in fact, although the FQ-440 is now sold out, it’s advertised on Mistsu’s website: http://www.mitsubishi-cars.co.uk/evolution/

  • avatar
    gosteelerz

    It appears that torque per litre hasn’t changed much over the years. There is some improvement but is probably due to increased compression ratios.

    IMO the broadness of the torque band is the most important which is probably what made a BMW straight 6 such a nice engine to live with.

  • avatar
    Cabriolet

    I have no idea why everyone comes down on the VW 8V engine. It was designed by Audi back in the late sixty’s and used by VW in various sizes up to the present. Sure it is old but it does it’s job very well. I know many people who have put over 250,000 to 300,000 miles on these engines. I drove a few into NYC for over 30 years and they did just fine. Of course i drove a stick but the pick up was good and if wonders of wonders the traffic was moving i could do 60 MPH with no trouble at all. The gas mileage was good and it did not feel like a slug from a red light. I have a 25 year old VW Cabriolet that i use on the weekends that has this engine in the 1.8 version. The car is a ball to drive and only has a weight of 2,200 lbs. Of course the last 2.0 8V i had was a 2004 VW at 3,200 lbs it was still a fun car to drive. If i want power i have my MK6 GTI which has more power then i need but it nice to have around.

  • avatar
    ktm

    Yeah, this is a useless metric. All one needs to do is look at 600/1000cc sport bikes to see that they rule the n/a HP/L roost and make car engines look silly.

  • avatar
    orenwolf

    My RX8 handily beats those numbers with its’ 1.3L engine. ;)

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