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Everyone says that the 3-cylinder engine is not good. Why do manufacturers still desperately produce it?

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Everyone says that the 3-cylinder engine is not good. Why do manufacturers still desperately produce it?

Recently, I have seen this china YouTuber giving a very good explanation of why manufacturers are giving a bang on a 3-cylinder engine. 

The disadvantages of a 3-cylinders engine are like a open secret everyone and even the manufacturer knows it. The main reason most of the car manufacturer still goes ahead and produce 3-cylinder engine have 3 core business benefit. And as what the YouTuber is saying, it is like one stone kill three birds. There might be a little dissatisfaction with the consumers but with extensive marketing of the 3-cylinder engine, consumers will still buy.

And so the factor that concluded the resurgence of a 3-cylinder engine is fuel economy, emission reduction & R&D costs.

Actually 3-cylinder engine is nothing new to the market. Suzuki has been using a straight 3 engine in 1979 on a Suzuki Alto.

Suzuki_Alto_101.JPG

And some of the notable mention of a 3-cylinder engine car.

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Subaru Justy

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Saab 93

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Alfa Romeo 33

All these cars have a glorious history about straight 3 engine. But the 3-cylinder was still eventually gotten abandoned by the manufacturer.  Mainly is because of the 3-cylinder engine have this unrefined(wobbly) movement that is very annoying.

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When the 3-cylinder engine is running, although the internal interaction forces are just balanced, but the torque is unbalanced. This would lead to a 3-cylinder engine undulating wavelike motion on both ends. And like a see-saw, the engine will shake from one end to another. In the early days of the 3-cylinder engine not only it will shake, but the sound frequency of the sway when idling at low speed is also close to the frequency of our brainwaves at around 15Hz. This will cause the idling of the 3-cylinder engine to have a very significant noise that is easily detected by humans. There is a lot of complaints in the past, making the manufacturer had to give up on 3-cylinder engine.

But nowadays, one of the reasons why the comeback of the 3-cylinder engine is because every country has a stringent environmental protection law and emission guideline. And every government is asking the manufacturer to reduce the car's fuel consumption.

There is a US & Japan automotive masterplan that states by 2020, the average car fuel consumption must be less than 6L / 100KM & 4.9L / 100KM. China also has a rule that stipulates the average car fuel consumption must be less than 5L/100KM. So once again, the manufacturer re-introduces the 3-cylinder engine. 

There are 3 viable ways the car manufacturer can reduce fuel consumption. Firstly, invent and build an electric vehicle, secondly is to reduce vehicle mass weight and lastly is to reduce the amount of fuel burned per revolution. The car manufacturer is clever, so in the end, they still chose the 3-cylinder engine. Because other solutions have obvious disadvantages to car manufacturers. 

If you want to build an excellent electric vehicle, you need to pour a lot of R&D and investment to specifically research and develop the vehicle structure. Tesla is the world's most famous electric car manufacturer and they only have 4 - 5 models in total for now. But just 2018 itself, Tesla's R&D has spent $1.46 billion. Volkswagen's R&D spending in 2018 was only 14.7 billion. But, Volkswagen group itself have more than 100 models of vehicle on sale. Averagely each model R&D investment is much lower than Tesla.

The traditional car companies want to build electric cars on a larger scale, they need to reinvest in R&D costs. Maybe as much as what Mr. Elon Musk has spent and they must be thinking that if I already have the money inside my pockets, why do I still need to fork out?

So if building an electric car is not feasible, how about weight reduction? Reducing vehicle weight is also not a good choice. Here's an example, the average fuel consumption of a passenger car in China in 2018 is 5.8L / 100KM, and from the target of 5.0L / 100KM in 2020, there are a 9% fuel savings to be met.

Published bt Southwest Aluminum, Aluminum alloy components promote the modernization of the automotive industry. The research report shows usually every 10% of the vehicle's own weight, there will be an 8% reduction in fuel consumption. Simply says, car companies can achieve fuel consumption goals by 2020 by reducing weight 11.2% of weight for each vehicle.

The average passenger car in China weights about 1,456kgs. It is equivalent to averagely per car companies need to reduce 163kgs per vehicle. The data released by Gasgoo.com shows every 1kg of a vehicle weight loss, the production cost per car will increase by 60RMB (SGD $12). To sum it up, there will be an increase in 9784RMB (SGD $1,898) of production costs per car. And just a mathematical analogy,  Volkswagen sold 10.83 million cars in 2018. If all these cars, the production cost of each car increased by 9784RMB, just imagine how much Volkswagen has to pay per year? It is a whopping 106 billion of manufacturing costs!

This is as good as you go down and just want to have a hair cut,  but the barber keeps asking you to sign a $200 membership in order to cut for you.

tenor.gif

The idea is the same, no one wanna fork out the extra for paying the same stuff you are getting. So on the weight reduction part, this is not the optimal solution for traditional car companies.

The last resolution will be a 3-cylinder engine left. So how to control the amount of fuel in the 3-cylinders? A research finding from SAIC-GM Pan-Asia Research Center. If the displacement of a single cylinder is small, then the surface ratio will become a larger increased surface cooling loss. With the same small displacement of a 1.5L engine, efficiency of a 4-cylinder engine is significantly lower than a 3-cylinder engine. In laymen terms, 1.5L of 4-cylinder engine is not as fuel-efficient as the 3-cylinder 1.5L.

So car companies want to reduce emissions, right?

Then the only solutions are 3-cylinder engine. The modern engine mostly are built with modular technology. This helps to reduce the R&D costs for a 3-cylinder engine.  BMW has introduced officially of using modular technology, BMW's new B-Series 3, 4, and 6-cylinder engine more than 60% of parts can be shared and parts are shared between gasoline and diesel engines have also reached 40%. Using a unified architecture when developing the engine, and cut off excess cylinder if needed. They just need to do a simple modification with matching components and they can create a 3-cylinder engine!
tenor.gif

There is no additional research cost at all!

So with one less cylinder, it can help the OEM save a whole set of institutions like pistons, rods, spark plugs and so on. These cost savings are immediate.

So the end of the day, the 3-cylinder engine not only meets car companies cost reduction, but it also can meet the fuel consumption set by individual governments, and there isn't an additional investment in R&D.

With that, I shall present you with the upcoming 3-cylinder engine from the latest 2019 Thailand international motor expo!

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Nissan Almera

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Honda City

 

 

 

 

 

 

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The reason is very simple. 

Save 25% on cost. 

And spend zero on R and D. 

If you have a 4 cylinder engine then just make it with one less cylinder. 

So if 3 cylinder save 25% then 2 cylinder engine can save 50%?

Yes but only half the power. If the car is very small then enough power. If bigger then need 3 cylinder. 

:D

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The article kept mentioning about lowering building costs and getting lower emissions etc, but what about drivability and overall drivetrain refinement? 

The title already said we consumers tends to jeers at 3 cyln engines becos of its lack of refinement and driveability. Yes today's engine tech has largely eliminated the inherent buzziness of a 3 cyln engine (I will never forget  the sheer crap sounds and feel from the 1988 Daihatsu Charade 1L), technologies couldn't overcome the fact that there's only 3 cyln to work with.

Power delivery from a modern forced fed 3 cyln are still generally uneven. You see the torque op in particular, have u ever seen a flat torque curve from a 3 cyln engine before? And reality have shown that actual FC of these tiny 3 cyln engines are anything but close to the manufacturers claims. 

Ford 1L Ecoboost is a prime eg. Engineers sang praises on it when it was 1st released, but very soon consumers found out that the average fuel economy of that tiny engine was anything but fuel saving. Ford said it can replace a NA 1.6-1.8L engine, but ended up the FC was closer to a 2L NA engine in real life...  

Edited by Cheefarn
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What's good for the car maker doesnt mean it will be good for the consumer.

I will avoid 3 cylinder engines at all cost regardless of what ppl say.

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I speak from my last year experience in renting a Audi A3 1.0 from our local “Audi on Demand” website.

I had the car for 1 day and while I like the low end  torque the 3 cylinder 1.0 litre Ea211. What I can’t stand is the buzzy noise i get when the engine is going about from 1500 to 2000 rpm. To save fuel, the DSG upshift early and by 65km.hr you are in 7th gear and cruising at 1200rpm, that’s the part where you can feel the vibration and buzzy feeling from the engine.

 

Edited by No_worries
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3 hours ago, Jamesc said:

The reason is very simple. 

Save 25% on cost. 

And spend zero on R and D. 

If you have a 4 cylinder engine then just make it with one less cylinder. 

So if 3 cylinder save 25% then 2 cylinder engine can save 50%?

Yes but only half the power. If the car is very small then enough power. If bigger then need 3 cylinder. 

:D

Is there such a thing as a production 2 cylinder car?

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Somewhat I feel more cost cutting than Fuel saving. Same capacity divide by 3 cylinders means each cylinder becomes bigger. Doesn’t that mean more fuel being sprayed? 

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25 minutes ago, Karoon said:

Is there such a thing as a production 2 cylinder car?

Yes, the most recent being the Fiat TwinAir 0.9L that is installed in a variety of small FCA cars. 

In 70s SG, I remembered the Honda Life and Subaru Sex had twin-cyl engines. More recently the Subaru Viki had 660cc twin. 

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42 minutes ago, Karoon said:

Is there such a thing as a production 2 cylinder car?

Tata Nano

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image.thumb.png.84515a1f74d7da057a150057b639db6d.png

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Actually the perfect engine is a 3 cylinder engine

but with 2 pistons per cylinder. 

No need for valves and camshafts and no cylinder head.

:grin:

image.png.ba3cb78c17797df7bf51b0d251f2eeff.png

 

 

Edited by Jamesc
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5 hours ago, Jamesc said:

The reason is very simple. 

Save 25% on cost. 

And spend zero on R and D. 

If you have a 4 cylinder engine then just make it with one less cylinder. 

So if 3 cylinder save 25% then 2 cylinder engine can save 50%?

Yes but only half the power. If the car is very small then enough power. If bigger then need 3 cylinder. 

:D

thats why bmw split straight six into two inline 3 :a-toast:

 

you are authentic Kerata Guru [drivingcar]

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My BMW M240i 3.0,6 Cylinders,average 11.2Km/L,my Friend's 218i 1.5,3 Cylinders can only get 13Km/L...so 3 Cylinders,not really save Fuel.

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7 minutes ago, ER-3682 said:

My BMW M240i 3.0,6 Cylinders,average 11.2Km/L,my Friend's 218i 1.5,3 Cylinders can only get 13Km/L...so 3 Cylinders,not really save Fuel.

Your fc is good. Someone I knew driving same car only told me the biggest issue w this car is same small fuel tank shared w the other 2series. 

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https://www.topspeed.com/cars/these-are-the-most-powerful-three-cylinder-engines-in-new-cars-ar183861.html

Modern 3 cy are OK for average performance cars.

Some makes register very good fuel savings comparing 3 vs 4 cy. Some makes make less. 

https://www.honestjohn.co.uk/real-mpg/

The traditional downsides of 3 cy have been much minimized in modern engines. So I don't have an issue with a 3 cy if it is well engineered, especially wrt the rest of the car including the tuning, turbo, exhaust and weight.

 

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