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Transportation Technology

Lotus Teases With a Fuel-Agnostic Two-Stroke Engine 269

Posted by timothy
from the ask-a-lotus-eater dept.
JohnnyBGod writes "Lotus claim to have invented a new, more efficient engine design. The two-stroke, flex-fuel engine can achieve, according to the surprisingly technical press release, 'approximately 10% better [fuel consumption] than current spray-guided direct injection, spark ignition engines.' The engine has a sliding puck arrangement to control its compression ratio, and has direct injection and a wet sump, to eliminate fuel leakage to the exhaust and the need to mix oil with the fuel, two common problems with two-stroke engines. Lotus engineering have released a video explaining the engine's operation."
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Lotus Teases With a Fuel-Agnostic Two-Stroke Engine

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  • Ford built a Fiesta with a two-stroke engine that achieved 1.4l/100km (that’s 168 mpg!) in 1996! Not a drawing. Not a experimental model. No, a real driving prototype car. Looked just like a normal Fiesta.

    I wonder why it took until now, for something that’s still worse to come out.
    If I were the Ford engineer, I would be angry as hell.

    • by _merlin (160982) on Friday December 11, 2009 @06:41AM (#30399782) Homepage Journal

      So where is this magical Ford engine at now? A one-off prototype car is no better than a single experimental engine.

      • by fruey (563914) on Friday December 11, 2009 @07:00AM (#30399858) Homepage Journal

        Various theories hint at the interests of the oil lobby to continue four-stroke dominance (just look at the low mpg of most american manufacturers in general) and perceived customer comfort being the most widely used trump. High fuel efficiency does not usually provide sporty acceleration, low engine noise, and high torque at low revs.

        That being said, no doubt many consumers don't care as much about that as the marketing departments of the automotive industry. In reality, noisy diesels have sold well in Europe (thanks in part to diesel fuel subsidies) and customers have bought poor performing, smaller cars for everyday use. They just don't make big margins on cars that sell for less than €8000 new. So once again striking a balance between shareholder interest (increasing profits) and global economic / ecological interest (decreasing emissions and oil reliance both by better fuel efficiency and better combustion of cleaner, more varied fuel) is an impossible mission.

        Until oil prices go up, don't expect any good technology to prevail. The four stroke petrol engine will die, but not before oil costs increase.

        • Re: (Score:3, Insightful)

          by dakameleon (1126377)

          Various theories hint at the interests of the oil lobby to continue four-stroke dominance (just look at the low mpg of most american manufacturers in general) and perceived customer comfort being the most widely used trump. High fuel efficiency does not usually provide sporty acceleration, low engine noise, and high torque at low revs.

          Uh... explain then why European & Japanese manufacturers can make high mpg with the same four-stroke engine technology? Oil lobby aside, the technology has more efficiency possible.

          And irrespective of that, two-stroke doesn't necessarily mean less fuel consumption - and is far more likely to mean higher lubrication oil consumption.

          In reality, noisy diesels have sold well in Europe (thanks in part to diesel fuel subsidies)

          Where on earth did you get the idea that Europe subsidises diesel?

          and customers have bought poor performing, smaller cars for everyday use.

          That's more likely to be a pattern of behaviour - distances between cities and key locations are smaller due

          • by fruey (563914) on Friday December 11, 2009 @07:36AM (#30400030) Homepage Journal

            Euro & Japanese manufacturers are less influenced by the US fuel lobby. Explain why petrol costs way less in the US : (the answer is taxation in Europe). The taxation strategy indirectly subsidises (it's not quite a subsidy, of course, but to the end user making one fuel cheaper than the other is akin to subsidy even if the difference is the level of taxation)

            Agree in part with behaviour patterns in Europe, but I've seen roads from Fort Worth & surroundings to Dallas clogged with large vehicles mostly used for a less than 20 mile daily commute...

            • Euro & Japanese manufacturers are less influenced by the US fuel lobby.

              My main issue with your argument above is that the oil lobby is somehow colluding with the US auto industry to maintain the primacy of the four-stroke engine, which is simply not true. The oil lobby is more overtly acting to discourage high efficiency standards legislation in concert with the (former) Big 3 because they don't want to put in the extra effort.

              The taxation strategy indirectly subsidises (it's not quite a subsidy, of course, but to the end user making one fuel cheaper than the other is akin to subsidy even if the difference is the level of taxation)

              A subsidy is a reduction below market price; this is a case of a preferential tax rate. I'm being pendantic, but it's a difference in end-user behaviour

              • Re: (Score:3, Interesting)

                by plastbox (1577037)

                People tend to buy for worst-case instead of average-case scenarios - just in case they ever take that holiday to Disneyland, they don't want to pack in to a compact. Europeans on the other hand take a train.

                What on earth are you talking about? You can't just make retarded, unsupported statements like that! We Europeans are quite fond of our cars, and have no problem packing a family of four into a typical European/Asian family car for vacation. if you think you need to drive a Hummer or a 2-ton pickup truck to get where you're going, then perhaps you should learn to pack your stuff with some common sense (and perhaps put your all-American family on a diet).

                Yes, that diet comment assumed a very clique image of

          • by bazorg (911295)

            Where on earth did you get the idea that Europe subsidises diesel?

            some 60% of the retail price usually consists on oil-products tax and then VAT on top of it. In some countries like Portugal and Spain the retail price for diesel fuel used to be some 25% lower because the oil tax was lower. Then the TDIs of this world became successful enough for people to used them on stuff that is not a lorry or a tractor and the price gap between petrol and diesel was reduced.

          • Re: (Score:3, Interesting)

            by sjames (1099)

            A well done two stroke won't consume lubrication oil, that's the whole point of the wet sump in the Lotus engine. Further, it can provide nearly twice the power for it's weight since each cylinder fires twice as frequently. It also means a two cylinder engine can run as smoothly as a 4 cylinder 4 stroke engine.

            As for engine power, Americans have adapted. Every time I see a commercial talking about a powerful V6, I recall that at one time V6 was the wimpy economy option and the V8 was the powerful option. At

        • by DarkOx (621550) on Friday December 11, 2009 @07:27AM (#30399984) Journal

          Don't forget one of the big 2-stroke killers in the USA was the as usual the EPA. Because they set at the emissions requirements as ratios; rather than say an absolute value per horsepower hour. A 2 stroke looks dirty compared to a four stroke if you compare the various amounts of controlled gases in a sample but they are often allot better in absolute terms; because they can do more work per unit of displacement and revolution.

          • by Skal Tura (595728)

            Same goes for Wankel engines.
            It's ridiculous that they are measured with the same standards than a completely differently working engine.

            By design, Wankel is way more efficient (all rotating parts, no complete turns in direction). Downside with Wankel is inexistant low rpm torque, which comes from a multitude of factors (ie. lower rotating mass for one)

            In wankel, on 1-cycle you have 3 ignitions, while on 4-stroke you have 1 ignition, and 4-stroke cycle is longer than wankel's ....

          • Re: (Score:3, Interesting)

            by Scootin159 (557129)
            Thus the air pump - just dump a certain percentage of ambient air into the exhaust prior to the test section, and magically your #'s start to look better.
            • Re: (Score:3, Interesting)

              by pavon (30274)

              My '79 truck had one of those. Only thing it was good for was decreasing gas millage (caused by having to operate the pump? or by increasing the pressure engine that the engine had to push against when expelling exhaust?) My parents yanked that thing off pretty quickly at the recommendation of our mechanic. But, to this day I cannot register that truck in the city because I have removed an "emission decreasing device", even though the actual emission are well below the limits, and the damn pump actually inc

          • Re: (Score:3, Interesting)

            by Dare nMc (468959)

            Actually the ppm (parts per million) ratios are gone for on highway in the US, it is purely a grams per mile emissions standard for on highway cars in the US [dieselnet.com]. It is percent emissions only for off highway. However, that's for the manufactures to meet, your local emissions test is going to be a PPM rating that they look-up for compliance, so I understand the confusion.

          • by dr2chase (653338) on Friday December 11, 2009 @01:29PM (#30404018) Homepage

            I learned to drive in a 2-stroke car -- a 1968 Saab, AFAIK the last 2-stroke car that could legally be sold in the US (50CID was the limit for that year, it was at or a hair under). They are not better in absolute terms, old style 2-strokes are just plain filthy. Their rear mufflers would not rust, instead they would become plugged with a mixture of soot and partially-burned gunk. If you left one of those cars idling for too long next to another car, you would leave an sooty oily spot from the exhaust. You could rejuvenate a muffler, if you had access to a trash fire or bonfire, by cooking it to bake/burn off the gunk.

            Using synthetic oil for lubrication helps a little bit, because it is formulated to burn better, but in general, there is no way that these cars were cleaner.

            So -- I actually drove one for years, actually worked on their exhaust system, actually left one idling next to another car for too long, and have seen all this with my own eyes. Where did you get your information? I'm curious to know what would cause someone to spout such obvious nonsense with such self-assured authority.

          • by Burning1 (204959) on Friday December 11, 2009 @02:21PM (#30404774) Homepage

            A 2 stroke looks dirty compared to a four stroke if you compare the various amounts of controlled gases in a sample but they are often allot better in absolute terms; because they can do more work per unit of displacement and revolution.

            That's only true because they have one ignition event per revolution per cylinder. When you burn gas every revolution rather than every other revolution, you're going to perform more work per unit of displacement, per revolution yes.

            But you aren't necessarily going to perform more work per volume of fuel consumed, or more work per volume of pollutants released.

            The common 2 stroke engine blows a lot of gasoline (unburned hydrocarbons) out the exhaust, because the exhaust port must, by the nature of the common 2 stroke, be open long after air and fuel is sucked into the engine.

            Likewise, they produce foul smelling fumes, because oil must be mixed into the fuel. The common 2 stroke uses the crankcase as a pressure chamber to force air into the cylinder. Because the crankcase cannot be filled with oil, the fuel it's self must lubricate the engine, requiring a mix of oil to be introduced to the gasoline. The result is an engine that smells like a 4 stroke with badly worn out rings and valve guides.

            Now, there are a few designs that work around these issues:

            Diesel 2 stroke engines use exhaust valves, superchargers, and fuel injection. Because fuel is not injected into the cylinder until long after the intake port and exhaust valves have closed, the engine does not blow unburnt fuel out the exhaust. And because a supercharger is used for exhaust scavenging (removal) the crank case can be filled with oil, eliminating the need for premix. Anyone who's been near a diesel locomotive can attest that it doesn't smell or smoke like your typical 2 stroke.

            The same technology can be employed with 2 stroke gasoline engines. Gasoline Direct Injection with supercharging has some clear advantages over traditional 2-strokes... Never-mind the fact that the supercharger could be used to produce some pretty insane power output out of a small displacement engine.

            2 strokes also have the advantage that they are quieter than your typical 4 stroke. The only reason people tend to think of them as loud is because they don't require much in the way of silencing.

            Anyway... Long rambling post. Short version: no, traditional 2 strokes are not clean. Modern 2 strokes show a lot of promise.

          • Re: (Score:3, Informative)

            by pyrr (1170465)

            Eh, the power-to-weight ratio is good on a two-stroke, because they often can just skip the whole oil-sump design element altogether (total loss lubrication). You can't do that in a four-stroke without wrecking the cylinder walls on the non-induction strokes.

            If you take a two-stroke with an oil circulation system, say a Detroit Diesel Series 71 or Series 92 engine, you just wind-up with an exceptionally dirty (from a pollution standpoint) engine that gets mediocre fuel mileage and has an odd power curve,

        • by rufty_tufty (888596) on Friday December 11, 2009 @07:39AM (#30400036) Homepage

          "In reality, noisy diesels have sold well in Europe "
          Speaking as an Englishman and part time car nut: noisy diesels would sell rubbish,
          My GF's diesel Ford is quieter above 30mph than my petrol Honda, once you get above about 2000rpm when the turbo starts to kick in the diesel has more torque and the difference in noise is impossible to tell, but the extra torque means that you can rev the diesel lower. At idle my petrol Honda is slightly quieter but the idea of noisy/dirty diesels is old.
          Now at peak revs the petrol produces more power and I don't see me putting a diesel engine in my motorbike anytime soon, but for me the competition in none race cars has already been won by the diesel.
          Except of course that the last Monte Carlo 24 hour race was won by a diesel...

          • Re: (Score:2, Informative)

            by plastbox (1577037)

            According to Wikipedia [wikipedia.org], Diesel has the highest energy density of all the more popular fuels and as anyone who has ever driven a new diesel will know, torque, noise, etc. are non-issues.

            Would we even be having this silly discussion if not for those blasted average Americans? =P

          • ....don't see me putting a diesel engine in my motorbike anytime soon

            Too bad, apparently they are fun to ride. Neander 1400 Turbo Diesel Motorcycle Test & Review [motorcyclecruiser.com]
          • Re: (Score:3, Interesting)

            by pyrr (1170465)

            ...I don't see me putting a diesel engine in my motorbike anytime soon...

            Hayes Diversified has been developing a diesel enduro (http://www.hdtusa.com/vehicle-m1030-m2.php) for military applications, it seems like a pretty neat bike, if they start selling them to civilians, I'd really have to have a look at that.

            Also, there are some Royal Enfield diesel bikes. They have the vintage British Twin styling that RE licensed so very, very long ago (I guess it's a timeless design, especially in India), and the charming purr of a diesel engine. I must say I'm tempted by those too, but

        • by emilper (826945)

          noisy diesels have sold well in Europe (thanks in part to diesel fuel subsidies)

          pray, tell, which Europe are you writing about ? is it Europe nearby Jupiter ? Did NASA discover semi-intelligent life there (intelligent enough not to tax fuels, not intelligent enough to stop from subsidising them) ?

        • by Skal Tura (595728)

          Actually, higher fuel efficiency does likely translate to more power. But when it translates to more power, it's swapped to smaller engine, underpowered one, and then the fuel consumption is again higher because it's currently going on high loads.

          For example, an old RWD corolla.

          Stock 1.6liter, carburated engine. Producing around 70JIS HP. Sounds like doesn't consume much, yes?
          minimum 8liters per 100km (@80km/h highway), practically mixed city + highway (@100km/h) translates to 12liters per 100km, sometimes

        • Re: (Score:3, Insightful)

          by dargaud (518470)

          So once again striking a balance between shareholder interest (increasing profits) and global economic / ecological interest (decreasing emissions and oil reliance both by better fuel efficiency and better combustion of cleaner, more varied fuel) is an impossible mission.

          Why should it be the state's interest to ensure shareholder value for private companies ?!? And honestly, if the state mandates fuel economy on new cars and forces a change in production lines, I have no fear the companies would adapt their lines to make sure their bottom line does not drop. Destroying the economy my ass.

      • by jamesh (87723)

        Possibly it had problems meeting emissions standards? That's just a guess though. Two stroke engines aren't typically as clean as four stroke engines, although I don't know what technical marvels they implemented to get 168mpg.

        That said, if it's burning 10% of the fuel of an SUV it can't have been that bad...

        • by Firethorn (177587) on Friday December 11, 2009 @08:08AM (#30400188) Homepage Journal

          I don't know what technical marvels they implemented to get 168mpg.

          From my understanding, it'd be set up like the huge ship based two stroke diesels. You utilize a turbocharger and direct injection into the cylinder. That way you're not blowing gas/oil out with the exhaust. You can control precisely how much and when fuel is introduced into the chambers.

          Then you end up with an engine that's almost half the weight for the power. Cooling needs can even be reduced because you can use the air during the flush phase to help cool the engine.

      • by willy_me (212994)

        I remember reading about super efficient fuel injected 2-stroke engines back in 1990 - so the idea has been around for a long time. Implementing it in an efficient and reliable manner must be difficult.

        But just the other week I found a mass produced engine that implements the idea. Have a look at the new 600cc engine from ski-doo [ski-doo.com]. It's a 2-stroke engine that runs on gas - without the oil mixture. Oil is still used, but it is injected directly onto the main crank on an "as needed" basis. Overall oil

      • by geekmux (1040042) on Friday December 11, 2009 @08:50AM (#30400408)

        So where is this magical Ford engine at now? A one-off prototype car is no better than a single experimental engine.

        Oh, please, isn't the location obvious? It's sitting in the "high-priority" warehouse, right next to the Ark of the Covenant and the Roswell "balloon debris"...

        We'll get to it, in 30 years, 8 months, 4 depressions, 12 corruptions, and 20 trillion dollars in oil profits from now...

        Until then, YMMV...

    • by NoPantsJim (1149003) on Friday December 11, 2009 @06:54AM (#30399832) Homepage
      Yes, but keep in mind, it still looked like a Ford Fiesta.
    • by jimicus (737525)

      Purely out of morbid curiosity, what was the acceleration like? The last fiesta I had you needed to boot the damn thing to get to motorway speed before you ran out of slip road to merge into the motorway traffic - and that was a vanilla 4-stroke petrol engine (albeit the 1.25l model)

    • I wonder why it took until now, for something that’s still worse to come out.

      Worse in what aspect? While that is an impressive mpg for any car, the lotus engine has addressed several specific deficiencies with traditional 2-stroke engines, principally the requirement to mix oil with the fuel to lubricate the engine. This has a significant impact on the emissions. It can also run on a variety of fuels. This is one heck of an achievement

      oh and

      Ford built a Fiesta with a two-stroke engine that achieved 1.4l/100km (that’s 168 mpg!) in 1996!

      [citation needed]

    • by rcs1000 (462363) *

      I've googled and can't find this car.

      Source please?

    • by Raptoer (984438)

      If I had to take a guess it would be because the ford used the same design as previous 2 stoke engines, just in a different form factor to fit into a fiesta. Two stroke engines usually suffer from having to burn their oil at the same time as their fuel and letting fuel leak out the exhaust (since the intake and exhaust from the chamber happen at the same time).

  • They can be run on multiple fuels [wikipedia.org] (or indeed, mixtures thereof) and would be ideal for a series-hybrid vehicle, where the drivetrain could be eliminated (it was the weak point in the turbine cars [wikipedia.org].)

    • There is definitely an advantage in running very hot and fast. Waste heat might actually be of use that way as well.

      • by drinkypoo (153816)

        The Chrysler turbine engine actually had a regeneration system to feed exhaust gases back to the intake to lean the air-fuel ratio instead of decreasing speed, so that it would keep the motor spooled up and hot. The biggest problems with it were in the primary gear drive which brought output RPMs down to transmission levels, and in the volume of exhaust gases. A smaller, more modern car could have a smaller turbine yet, and thus less exhaust.

  • by Fantastic Lad (198284) on Friday December 11, 2009 @07:03AM (#30399878)

    This drives me nuts.

    What about this is new? Does it exist due to breakthroughs and material science we didn't have available thirty years ago? Not that I can see.

    Which means this is nothing that a team of imaginative engineers couldn't have come up with long ago, and likely would have, (and probably did) if they'd been allowed to. Fuel efficiency means the oil billionaires, (the people who have been running things since forever), make less money. The only reason this is happening now is because the corrupt deals being cut in Copenhagen [cop15.dk] with regard to carbon trading and various other ass-backward plans are a means of making more profit in different ways and promise greater control over every aspect of our lives.

    Look, I'm all for efficiency and I'm sure the engineering team on this project are fine people. But this is bullshit. It's a press release which appears in the same breath as that Israeli company and their silicone battery. The people allowing this stuff to float to the top of global media-consciousness don't care about the actual state of human affairs or about the genuinely awesome things we could be actually doing with technology. This is about agendas and sculpting public awareness and making damned sure the slaves are tightly locked down.

    So, yeah, thanks Lotus. Very courageous of you to cautiously advance this lukewarm idea past the oil barons. Because crop-based fuels are SUCH a good idea.

    -FL

    • by squizzar (1031726)

      This engine looks to be a lot more complex than the usual two strokes, so it will cost a lot more to manufacture and maintain, a lot more to design and engineer, will have lower yield rates/higher failure rates so it will cost the customer a lot more money. So, as a consumer of engines, do you spend possibly twice as much on the engine because it is 10% more efficient? If the major cost is the engine itself and fuel - as has been the case up until recently - is comparatively cheap which will you buy? As

      • This engine looks to be a lot more complex than the usual two strokes, so it will cost a lot more to manufacture and maintain, a lot more to design and engineer, will have lower yield rates/higher failure rates so it will cost the customer a lot more money. So, as a consumer of engines, do you spend possibly twice as much on the engine because it is 10% more efficient?

        They key words there being "two strokes". It's very possible it's still cheaper to make and simpler to maintain than the equivalent powered four stroke engines.

    • by rufty_tufty (888596) on Friday December 11, 2009 @07:48AM (#30400092) Homepage

      Dude, Chill!

      Let's assume you're right and it could have been done 30 years ago (it couldn't but I'll get to that later). It's newsworthy because no-one has done this before, in fact it's more newsworthy if someone has a really obvious idea that no-one has done before. I'm sure the first person to stick an internal combustion or steam engine on a cart was told it was a really obvious idea, but the first horseless carriage still deserved to be big news. I'd certainly class a major engine development as being as newsworthy as the latest revision of the Linux kernel being released.

      As I understand the article they're using direct injection similar to that used in modern performance diesels. This is a relatively new technology that requires very high pressure fuel injectors which are still a developing technology and weren't available 10 years ago never mind 30. Don't forget mechanical engineering is a much slower moving field than software - they have to design and test things in their field before they release them ;-)

    • by Raptoer (984438)

      Oh, and the government has put spy chips in our heads too!

      In all seriousness, this whole big oil conspiracy is a load of junk. I'm sure the oil companies would do that if they could, but look at it from the car company point of view. If a car company could come out and say "Hey! we got a car that gets amazing mpg and behaves just like any other car!" they would have an instant fortune. How exactly would oil companies go about stopping these companies? I've never heard of oil companies buying car companies,

      • In all seriousness, this whole big oil conspiracy is a load of junk.

        You say that with such certainty that you must have some pretty solid reasoning and knowledge on the subject. --Or be operating from a comfortable state of nearly perfect ignorance. Let's see which it is. . .

        I'm sure the oil companies would do that if they could, but look at it from the car company point of view. If a car company could come out and say "Hey! we got a car that gets amazing mpg and behaves just like any other car!" they wou

    • Which means this is nothing that a team of imaginative engineers couldn't have come up with long ago

      So is most of the new technology that you see. Even special relativity is obvious in retrospect.

      • So is most of the new technology that you see. Even special relativity is obvious in retrospect.

        You appear to be suggesting that everybody who has been thinking about how to improve internal combustion engines over the years simply failed to come up with anything smart.

        If you read through just the examples posted among the comments for this story, I think you'll find such a position is untenable. Heck, there's one example in an adjacent response to this exact post which describes a significantly more effic

        • You appear to be suggesting that everybody who has been thinking about how to improve internal combustion engines over the years simply failed to come up with anything smart.

          No, merely that a lot of the improvements we've seen in internal combustion engines have been along these lines (things that were physically possible decades earlier but needed someone to think of them). The fact that we haven't seen this particular improvement before just means that no one thought of it. No conspiracy needed.

    • Yes, Two stroke engines have been around for a long time. However, this engine purports to be a clean two stroke - something that has not been around a long time. Anyone with an mid-70's two stroke motorcycle could probably go around the block before biking in their own smoke - so yes, this is new.

      The advantage of this "system" is obviously 1) it's light, 2) it's clean; 3) it can use multiple fuel types.
      1) A light engine can be combined with a generator; a battery. Think Electric-Car.

      • Yes, Two stroke engines have been around for a long time. However, this engine purports to be a clean two stroke - something that has not been around a long time. Anyone with an mid-70's two stroke motorcycle could probably go around the block before biking in their own smoke - so yes, this is new.

        That's apples and oranges. Two stroke engines of the kind you're referring to had (and still have) oil mixed in with the fuel so that they self-lubricate. As the oil burns, it is indeed very smokey. This has exa

    • To paraphrase Robin Williams; Never have I seen a slashdotter in more dire need of a blowjob.
  • I wonder how this compares to the OPOC engine that is being developed by the same guy who did the TDI for VW. Check out the nifty flash animation: http://www.ecomotors.com/ [ecomotors.com] . I think the new found focus on economy is starting to (finally) spur some innovation in this area.

  • Not only is it a two-stroke engine, which are inherently more efficient than four-stroke engines, but it also limits the moving parts to a minimum. And Lotus never boasts about something it cannot do. However, I'd like to see a multicylinder version of it.

    And that's no mean feature when you see the number of moving parts in today's engines fitted with variable valve timing/lift systems (which, of course, the switch to electric propulsion will avoid altogether).

    The question is, however, is it too late? And i

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