Volkswagen’s New Engine Cycle – The ‘Budack’ Cycle
100 Comments


Hello, everyone and welcome we are inside of the 2018 Volkswagen Tiguan. This is Volkswagen’s first model which is running their new EA888 engine running the new Budak cycle, this new engine cycle which Volkswagen has developed it was named Budak cycle by Volkswagen after their powertrain engineer who developed it. Now this cycle is basically a variation of the modern Atkinson cycle, which is a variation of the Miller cycle without a supercharger, so what does all this mean? Well that’s what we’re gonna get into in this video. How does this engine work? Why is it more efficient? That kind of thing. So in order to understand that we need to understand the Atkinson cycle, and the modern Atkinson cycle what it is is during your intake stroke, everything happens as normal your intake valve opens your piston moves down it pulls in that air fuel mixture now during the compression stroke you leave that intake valve open for a short duration, so you’re pushing out some of that air some of that intake charge and what this does is it lowers your effective compression ratio so now your compression ratio is smaller than your expansion ratio because your expansion ratio has remained the same that never changes now by having a lower compression ratio than your expansion ratio. You’re able to extract more useful work out of it so the whole idea is the piston has a longer distance to travel down and expand outward than it is compressing that gas so more of the energy from combustion is turned into useful work the ultimate goal is that the at the bottom dead center of the Atkinson in cycle, what happens is you’re at atmospheric pressure that’s the ultimate goal. So that means you’ve turned all the available heat and pressure from combustion into useful work the Budak cycle, the cycle which Volkswagen has developed is basically the same thing except instead of opening the intake valve for a longer duration you’re closing that intake valve sooner so during the intake stroke you’re going to close that intake valve before that piston reaches bottom dead center now this is effectively doing the same thing you’re reducing the amount of air that you pull in and as a result your compression ratio is less than your expansion ratio and because of this of course you’re going to have greater efficiency so the specific output of the engine goes down when you’re running this mode, but the efficiency goes up, so it’s great you know when you’re cruising on the highway when you’re at low loads and Volkswagen has a solution for when you want power, so when you do want power. There’s a cam lobe switch, so there’s this little pin that forces the cam to a longer duration profile and actually a higher profile so you open the intake valve more and you open it for a longer duration and so that’s for this power cycle when you you know you put your foot down you want full power from the engine it gives it to you and it switches over to you know the normal Otto cycle that most engines out there are running so they do have you know a pretty cool visualization of this 3D model and so I’ll try to put these two intake strokes side-by-side and hopefully you can see the difference you know the intake valve running the budak cycle closing sooner than you know when you’re just running the traditional Otto cycle and you know you want to make more power for that version. So pretty cool that you know it’s able to switch between these two different modes it’s not you know the most groundbreaking thing ever. They’re just you know it’s a it’s a different take on the Atkinson cycle, which is a way of increasing fuel economy so cool they’ve taken another approach to it and you know come up with this clever solution to differ the expansion ratio from the compression ratio. So has this engine cycle change been an effective means of increasing fuel economy? Well it certainly has improved from the previous generation Tiguan but you’re still only getting 27 miles per gallon on the highway Even if you get the all wheel drive version or the front wheel drive version both of them getting 27 miles per gallon on the highway which for this segment you know certainly isn’t class-leading the Honda CRV the Mazda CX-5 the Subaru Forester all of those you know able to achieve the low 30 mile per gallon range on the highway so they are able to do better than you know this engine cycle. This is a fairly heavy vehicle so that probably plays a big role in its fuel economy rating it is cool that they have improved it although you know compared to the competition they’re not exactly at the top. If you guys have any questions or comments feel free to leave those below. Thanks for watching!

100 thoughts on “Volkswagen’s New Engine Cycle – The ‘Budack’ Cycle

  1. This video makes out that under normal conditions during the intake stroke the cylinder completely fllls with air. You couldn't get that even with a turbo. There's a reason there's a big valve in the throttle body that literally works by restricting the amount of air the engine can take in under induction.

    On low to mid throttles there's hardly any air in the cylinders. If you pulled a full charge every intake stroke you'd need the correct amount of petrol to get the stochiometric ratio and the engine would be running permanent full throttle.

    I can't see how this helps anything other than marketing blurb.

  2. It's not exactly a new one it's just a blend of Atkinson cycle and Otto cycle just mixed both… In one engine no more Atkinson only or only Otto combination of both excellent to be honest a bit stolen from Toyota but good (1.2 turbo Toyota has exactly that) 2015 punchin out 116 Hp quiet good and a punching amount of torque not bad at all with the turbo giving a very usable torque from low down up to high on the revs max torque from 1500 to 4000 rpm enormous range

  3. What they've done is to the public absolutely nothing they can't make electric cars so they have to keep on playing with the diesel and petrol

  4. If it's a heavier vehicle than the competition and out-accelerates them then mission accomplished. You're not comparing apples to apples.

  5. I would like to see a fuel economy comparison with the engine operating at both adjustment extremes. Acceleration curves would also be nice with corresponding fuel economy underneath.

  6. Interesting. But I have a two-part layman's question: what is the practical advantage of closing the intake valve over leaving it open (and pushing some of the fresh charge back into the intake manifold)? Couldn't this lead to a vacuum effect during the bottom half of the intake stroke, which would rob the engine of some of its mechanical efficiency?

  7. If this is coupled with supercharger or turbocharger, then this will benefit from having less intake resistance than conventional atkinson cam timing.

  8. Don't forget the "BI-cycle" which is what you will be riding once your Volkswagen vehicle breaks down (sooner than later) .

  9. Excellent explanation Theory makes sense. Reality is it’s over complicated for typical mechanic , more bells and whistles to break cost of production, and repairs go up with fuel savings insignificant Better to have a simple more reliable engine

  10. Way to overly complicate something that wasn’t broken, and including several complicated components to fail.

  11. A 2wd Ford F-150 with the 2.7 Ecoboost gets 27 mpg on the highway but will stomp that VW. What exactly is the point of making this ‘new’ cycle and all the complexity if it’s not even up with its normal competition. My wife’s 2017 Escape averages about 27 mpg and gets low 30’s going 72mph.

  12. So if I put a different cam grind in any existing engine… I get to call it some new type of engine cycle? ?

  13. Of course, this is Volkswagen, so if history tells us anything. Volkswagen has brought out the latest and greatest engine since their, "CLEAN DIESEL ". Oh wait, that was BS. So how much is VW paying to spread the word of their latest technical breakthrough? NOT BUYING IT.

  14. Having knowledge & experience of VW products from the past .
    I am actually afraid of it.
    No not the innovation folks.
    It's the future repair BILLS.

  15. Here's the deal. Mid 80s, my cousin who worked for Ford motor co. Leased 2, 4 door escorts, 4 cly diesel, manual transmission. We ran all over east Tennessee 4 & 5 people in each vehicle. A/c running all the time, 70 & 80 mph sustained not uncommon . Our mileage calculations: 60 mpg. So…what's the problem? Believe it or not folks, I know, I was there drove one for days. We were not easy on them. Mfg & oil co. Don't want you to have em. End of story.

  16. This is not a "new cycle" its a four-stroke engine with what is effectively the wrong camshaft that does not count as a new cycle "oooo I retracted my valve timing 15 degrees to early"

    slaps roof of car "this bad boi fits soo many camshafts with lobes that are not correctly positioned"

  17. Why not just include a few lines of code that makes it look like it’s Budacking and save the effort and expense of actually doing it?
    Oh yeah, that parking lot with 300,000 vws that you can see from space…

  18. The mpg is not as good but how much more hp and torque are we getting? How much more fun to drive is it? The forester is not gun to drive!

  19. I like this concept, does it have direct injection also? The Atkinson cycle or this Budak cycle allows us to use the cheaper 87 octane fuel without worrying if it will cause pre-ignition

  20. I had a 1991 toyota corolla that got a very consistent 37.5 mpg!!! And it was zippy little car that would not have to wind out on the freeway. Seems like we r going backwards.

  21. There are only so many things you can do to a combustion engine. At long last its coming to the end of its life. Hydrogen Cell or Thorium power is the future….
    Next gen battery power, before the Hydrogen Cell becomes cheaper and available to masses, will be Flouride Ion.

  22. I can get 27mpg in my Lincoln town car.(Hwy) and have got as much as 30 mpg on one longer trip on Cruze at 60m/h you would think they would have come up with something more inovative

  23. What is the point of closing the intake cycle, effectively DEcompressing, just before the COMpression cycle?

  24. Doesn’t seem to make sense to over complicate the engine For just a little bit of efficiency more things to break

  25. Doesn't nearly the same thing of her when you open the intake valve before the exhaust valve is closed? It causes reversion, but it does also lowered effective compression ratio and any loss of compression ratio reduces the amount of work you're putting into the project in the first place so I don't know how much more efficient it actually can be shown to be.

    Having a switch between those two functions however is interesting. Sounds like it's more effective that shutting off several cylinders and hat 4-cylinder still have to put your bunch of dead weight around in an engine. One of the stupidest ideas I've ever seen in my life.

  26. It's not more efficient than the Atkinson. But, worhout any Search, I can predict there will be less carbon buildup for DI engine

  27. @engineering explained , why aren't they just using electronic valves yet? variable valve timing with cam shafts is fossil technology at this point

  28. By closing the intake early before bdc, wouldn't the piston be working against the fixed amount of air inside the camber?

  29. Didn't the ferrari modena have this system of a variable 3D cam lobe that would slide back or forwards. Its just variable valve timing but instead of making more power at higher RPMs it makes it worse… absolutely genius.

  30. Thankfully with EV cars set to dominate, we won't have any more nonsense like this, ICE is dead, it's ancient outdated engineering.

  31. I don’t understand why they’re having such a hard time with efficiency. Honda did it with VTECover twenty years ago. 15 years ago, their cars were safe, zippy and EFFICIENT.

  32. I'm just waiting for electronically operated valve train so we can adjust valve timing infinitely on the fly…

  33. The electronically actuated valve technology that a couple of engineering firms are working reliability issues out of has this and all other variable valve event tech beat by light years, all aspects of intake and exhaust valve events continuously variable. You can go from super efficient to blazing horsepower in a microsecond with total engine control, electric cars? Ha! Children's toys!

  34. Actually this should be a much better implementation of the Atkinson cycle, because you eliminate a lot of pumping losses that you would had if you close the admission valve in the compression stroke

  35. Sorry but the explanation given here is entirely wrong. The advantage of this type of engine's asymmetrical power cycle is NOT a lower compression ratio. That actually reduces the efficiency of combustion. Having a longer power stroke than the effective intake stroke works ONLY due to the use of fuel injection and supercharging to make up for the loss of brake mean effective pressure. The reality is that there is an improvement in low power output efficiency due to the reduction of resistance during charge compression. That's the goal of Atkinson and Miller cycle engine valve timing. After the intake valve closes the forced pressure can restore the bmep ratio for efficient combustion WHEN more power is needed but most of the time engines run at a very low level of power output and that's when this technique returns benefits. Technically, this valve timing restores more of a constant push to the combustion cycle rather than the fast explosion of the Daimler cycle engine it's based on and that is similar to the original Otto push cycle engines.

    Since Daimler (called Otto) cycle engines are least efficient at low power outputs this is a useful adjustment for that reality.

  36. Jesus they are all stupud
    Get rids of cams
    Use better metals
    Make them 700 pounds lighter each car
    [Drops mic]

  37. I felt the 2.0 turbo that put out a little over 200 h.p. was a much better engine. And that tiptronic transmission was a joy. VW is not giving the kind of value it once did in engine performance and economy in my opinion. Good review.

  38. Can you comment on carbon build up on direct injection engines and this one in particular. Are the horror stories real?

  39. A new cycle????? Who do you think you're kidding, all that means it a Otto 4 cycle engine with a different camshaft profile. Heck, I can do that with any engine and I'll name it after me.

  40. No mattef how you slice it or splice it
    It is stil a fossil fuel burner
    generating co2 and comtrubiting to global warming.

  41. So they built and engine, then said “how can we make less power?” . Looks like another german engine that will burn a quart of oil per 1000miles .

  42. I think it's a bit vain to make use of variable valve timing and claim its a while new cycle . But Thank you for the explanation.

  43. I call it "Budschit" cycle. Or variable valve timing? Wwwwhhhoooooo those Germans and their engineering skills. Not very good at software though huh VW? Buy M'erican!!!!

  44. Got this technology in my Polo GTI. Seems useful when you're trying to squeeze as many kilometers from a liter of fuel when you're just driving to work. I managed to reach about 18 kms/lt average, not bad for a supercharged 2.0 petrol!

  45. Is the effective increase in efficiency through the lowered compression ratio actually offsetting the energy loss from effectively pulling a partial vaccuum in the cylinder? Seem like pushing it back out would keep it at atomospheric pressure longer and achieve the same compression ratio thus making it more efficient?

  46. “Shultz, these fuel efficiency numbers look awfully high on our new engine.”
    “Herr Klink, I know nothzing! Nothzing!”

  47. It is actually a new cycle. When they refer to the Otto cycle, Atkinson cycle, Diesel cycle, etc., they are referring to the thermodynamic cyclical process the gases inside the cylinder are going through in terms of their pressure, volume, and temperature at every point in the combustion process. This is what determines the efficiency of the cycle, meaning how much useful work can be extracted from the burning of the fuel.

    The original Atkinson cycle engine actually had a completely different crankshaft setup with extra linkages that allowed the piston to travel down a greater distance on the combustion stroke than it traveled up on the compression stroke, giving it inherently different compression and expansion ratios. That is why he refers to current Atkinson cycle engines as "modern" Atkinson cycle engines, because they are simulating the difference in compression and combustion strokes through the use of valve timing changes. These engines actually have the same stroke length during both compression and expansion strokes (just like an Otto cycle engine), but the late closing of the intake valves makes the "effective" compression ratio less than the expansion ratio, improving efficiency.

    This new Budack cycle performs the same trick, it just closes the intake valves before bottom dead center (bdc) in the stroke instead of closing them after bdc. This does effectively change the thermodynamic cycle since the gases in the cylinder are undergoing an expansion process before compression that they do not go through in the Atkinson cycle. How this affects efficiency compared to the Atkinson cycle, I don't know, but it should be more efficient than the Otto cycle.

  48. Bro just 27 MPG remember the days when u got like 14 or 18 no madder what car u drove and those are good numbers

  49. My 2011 Hyundai Sonata Hybrid has hybrid battery ? and Atkinson cycle (8 years this came out) still getting 38 mpg City

  50. So it creates an "underpressure" by closing early, how is that different from how the throttle works? Doesn't that effectively do the same thing, restricting the amount of air/fuel mixture the cylinder pulls in?

  51. how about emissions? does this increase efficiency so less power but the burn is more efficient and therefore less emissions?

  52. I am dying to know why they've gone from a stick to an automatic why you can't find anything in the stick anymore nowadays and used to be years ago if you wanted an automatic you had to order it now everything is automatic and you can't even find a stick I want to know why and you can't tell me that an automatic is more fuel efficient than a stick they're not it's a proven fact that a stick is more fuel efficient than an automatic you can do things with a stick that you can't do with an automatic such as kickstart when was the last time you were able to kick start an automatic I don't think there is an automatic you can kick-start meaning if for some reason your starter happens to go bad you're basically s o l if for some reason you have to have it towed before you can even have it towed you have to drop the drive shaft unless it's front-wheel drive or unless you put it on a flatbed

  53. First, I think it will decrease the volumetric efficiency
    Second, as the volumetric efficiency decreases, the compression ratio will decrease too
    Third, as the compression ratio goes down, the engine efficiency will down too
    Am I wrong?
    Any tought?

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