3 cylinder turbo charged engines - Life Expectancy.

twofor1

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A friend is in the market for a new car and is considering the 1.0 Ford Focus Eco Boost, or the 1.0 Skoda Octavia TSI, Both are 3 cylinder Turbo charged petrol engines.

A lot of manufacturers are now using smaller 3 cylinder engines with turbos, I have heard the argument that it is expecting a lot from a very small engine, and these engines/turbos will not have a life expectancy anything near the 4 cylinder, 1.4, non turbo charged equivalent.

Any opinions ?
 

michaelm

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Turbos often end up leaking oil and are expensive to replace. If I was picking between those two options I'd go for the latter.
 

twofor1

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Thanks, the Skoda, at the moment anyway, would be his first preference too, but;

He intends to keep the car for 10+ years and does 15,000 kilometers annually.

You could reasonably expect to have no major issues, with the likes of Toyota, Mazda and I’m sure others, who still have similar 1.3 – 1.5 petrol, 4 cylinder, non-turbo models,

I know only time will give a definitive answer, but if there was an overwhelming ‘’Don’t Go Near A 1.0, turbo, 3 Cylinder’’ because…………., he would opt for one of the above instead.

If the smaller turbo, 3 cylinder is not going to last, it’s not worth going there for one who intends keeping for 10+ years, might be ok for those who trade in for new after 3 years or whatever.

So the question is do any mechanical people out there think the smaller turbo engine will have the same life expectancy, as the larger non turbo engine ?

Could you reasonably expect to get 10 years without needing to replace the expensive turbo and/or engine ?

My basic mechanical expertise says No.
 

RichInSpirit

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I wouldn't see a problem with this engine if it's designed well, which I'm sure it is.
Only to keep to the recommended service intervals.
 

Palerider

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Diahatsu charades had a one litre 3 cylinder engine diesel from 1988, a gutless engine producing 53bhp at best but it went on and on, the modern 3 cyclinder relies on a bunch of techno gizmos that may or may not be robust enough to give long and problem free motoring.

Assuming manufacturers design engines well is false, think of the Bmw diesels that were in the 5 series and other models that break/stretch timing chains as an example, did BMW stand behind their product design when this now well known fault came out....
 

roker

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Apart from the tubo, these 3 cylinder engines are the equivalent of having a normal 4 cylinder engine and hammering the guts out of it, of course it won't last unless they have discovered a new material to make them with.
 

RichInSpirit

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Been thinking a bit about this since and also talking to my trusted mechanic about it.
He brought up about the Diahatsu Charade having a 3 cylinder engine in the past that was super reliable.
Also if you divide 1000cc by 3 and multiply by 4, the engine components will have similar dimensions to a 1333cc 4 cylinder engine.
There are less parts, less to go wrong.
Also the power strokes are spaced at 120 degrees to each other so it might actually be smoother than a 4 cylinder engine.
Similar to 3 phase electric motors.
 

newtothis

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Some amazingly ill-informed posts in this thread. A comment like "3 cylinder engines are the equivalent of having a normal 4 cylinder engine and hammering the guts out of it" makes no sense whatsoever: does the person saying it have any qualification, or can point to any evidence backing it up? There were marches across the world yesterday protesting (with good reason) the side-lining of evidence based science by alternative facts of "common sense" backed by nothing but feelings.

In terms of the last post, yes 3-cylinder engines have perfect first and second order reciprocating balance (unlike 4-cylinders), but they have a rocking imbalance not present in 4-cylinder engines. It's not clear how either would effect the lifetime of the engine. And no, there's nothing really analogous in this with 3-phase electric motors, which have no reciprocating parts.

To answer the OP: there is nothing inherently less reliable about a 3-cylinder engine than a 4-cylinder of the same power output; if anything it is inherently more reliable, having fewer components. Turbo engines are inherently less reliable than non-turbo engines for the same reason (it's an extra component that can fail). However, they are extremely common in modern engine design: it's doubtful this would have sufficient practical impact for manufacturers to continue to use them.

The reliability of a particular engine is far more a factor of its individual design, the usage it's had and whether or not it's been maintained to schedule than anything inherent in its basic configuration. You'd need to look at the rates of failures over an extended period to get a sense of the design quality, and for newer cars this isn't available. Like investments, the only thing you're left with is using past performance to give an indication of likely future performance, i.e. the track record of the manufacturer (care needed here, as some models are designed and made by A, but badged and sold by B). In terms of usage, mileage is in general far more important than age, so the OP needs to look at the expected mileage over the 10+ years rather than just the timeline. Regardless of everything else, the car should be serviced, in particular the oil changed, according to recommended schedules.

Finally, when the OP asks "Any opinions?" the answer would seem to be "yes". Are they worth listening to? Up to the OP to judge that, I guess! I'd recommend looking to the evidence rather than opinion, though.
 

roker

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To newtothis. Yes I have engineering qualifications, it makes perfect sense that a small engine working hard is not going to last as long if it is giving the same output as a larger engine, but time will tell, and common sense will prevail over your arrogance.
 

newtothis

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Sorry you've read it that way: all I'm saying is that what may be apparent to some and "makes perfect sense" is simply an opinion until backed by evidence. You're statement that 3-cylinder engines "...won't last unless they have discovered a new material to make them with" is backed by what evidence exactly? Can you explain why 3-cylinder engines might be less reliable? And, yes, I have engineering qualifications too, so feel free to be technical about it.
 

Palerider

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Opel Corsa model D came with a 1.0 3 cylinder and a 1.2 4 cylinder, I drove both as I was looking for a starter car for one of the family, the Corsa 3 cylinder is known to be a poor engine, I found them noisy and the engine rattled like hell, these were 6 year old cars, I looked ata few and made extensive enquiries, I got him the 1.2 4 cylinder, a far superior drive and engine is miles quieter, just my experience.

New to this suggested that if you buy one ensure that you change the oil according to recommended schedules, oil is the lifeblood of an engine and whilst this seems logical advice I would ignore the manufacturers recommended intervals and change the oil every 6000 miles, it is inexpensive and will add years to the life of the engine.
 

noproblem

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Sorry you've read it that way: all I'm saying is that what may be apparent to some and "makes perfect sense" is simply an opinion until backed by evidence. You're statement that 3-cylinder engines "...won't last unless they have discovered a new material to make them with" is backed by what evidence exactly? Can you explain why 3-cylinder engines might be less reliable? And, yes, I have engineering qualifications too, so feel free to be technical about it.
Going on your thinking there's no need for anything bigger than a 3 cylinder v 4 cylinder. I don't need an engineer to tell me why i'd buy a 4 cylinder over a 3 cylinder given that they're the same price, etc. Don't think i'd be too wrong or, making a mistake either. Then again, what do I base that on? Good old time gut feeling, that's what.
 

newtothis

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Going on your thinking there's no need for anything bigger than a 3 cylinder v 4 cylinder.
Oh dear, oh dear: you'll have to explain how you can extrapolate from "3-cylinder engines are no less reliable than 4-cylinders" to claiming it's the equivalent of saying "there's no need for anything else".

Any engineering design decision is based on a multiplicity of requirements and a multiplicity of potential designs to meeting them: there's usually no one perfect design (if there was, all engines would converge onto it). Engine reliability is simply one of those requirements. 3-cylinder designs are better at meeting some requirements (their weight reduction influencing fuel economy and reduced cost of manufacture springs to mind) and worse at others (relatively poor noise, vibration and harshness or NVH). Fine if NVH is important to you and your gut tells you not to buy, it's your choice. But that choice is simply part of your buying decision in purchasing. Others will be less concerned with the drawbacks and more concerned with the benefits of reduced fuel consumption, lower cost and so on. Because 3-cylinder designs tend to be better at requirements more important in smaller cars and worse at those more important in larger cars you will tend to find them in smaller cars and so larger cars will tend not to use them. So no, I'm not saying there's no need for anything else. For the same reason, larger engines again tend to have more than 4 cylinders, which have a second order reciprocating balance issue requiring (costly) balancer shafts to correct as the size of the pistons gets large enough to make it apparent.

The OP asked a question about the reliability of 3-cylinder designs. I've pointed out that there's no inherent reliability issue with them, with reliability far more governed by individual design, usage a particular car is subjected to and whether or not it's been maintained to schedule. By the way, I should have said maintain "at least to schedule": I'd agree more frequent oil changes are a good investment if longevity is important to you, though with modern oils not as much as it used to be.

I've also recommended looking to evidence to establish the reliability of a particular model (or track record of manufacturer if the design is relatively new). On that, you should take a look at an independent source of information such as Warranty Direct's index, based on warranty claims in the UK. See http://www.reliabilityindex.com/top-100 where a model with a 3-cylinder option just happens to be #2 on the list of the most reliable cars.

Now ranged against a point of view that says look to the evidence, we have "perfect sense" and now "gut feel". That's fine if it's just an input to a buying decision; gut feel is what most people use in deciding to purchase a car (me included by the way: it's not a completely rational decision by a long shot). But please don't use notions of "common sense" or "gut feel" to claim somehow that of course 3-cylinder engines are less reliable unless you can point to some evidence to back it up.
 

AlbacoreA

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Personally I think the least complex engine will give least trouble in the long run.

But it really depends on the engine. You could have two simple engines one is designed well the other badly. One made well one made poorly.

You can only really go on people experience with them over time. You can't really make a judgement call on a new engine until it has been out a while.
 

newtothis

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Personally I think the least complex engine will give least trouble in the long run. .
Agreed: a good engineering rule of thumb is that simplicity begets reliability. Alas, most modern designs are heading in the opposite direction in terms of complexity. Having said that, modern engines are also significantly more reliable than those from years ago, so I'm not sure that much can be inferred from the principle as might be thought.

But it really depends on the engine. You could have two simple engines one is designed well the other badly. One made well one made poorly. .
One of my points exactly, though I'd missed the bit about quality of manufacture.

You can only really go on people experience with them over time. You can't really make a judgement call on a new engine until it has been out a while.
Agreed, though as I also pointed out track record does give some indication on likely outcomes.
 

roker

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Maybe I did not explain clearly, I was not referring that 3 cylinder engines where less reliable, but of the small size of the engine working very hard
 

mathepac

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The "fewer cylinders with turbo" vs. "more cylinders na" engine paradigm is shifting both up and down the price and performance ranges. Porsche have just released their new Cayman with a 4 cylinder turbo versus the previous models 6-cylinder na power-plant. Even the Yanks are beginning to let go of some of the 8 cylinder behemoths for 6s etc. We'll soon be back to V-twin's like Harley-Davidsons or single cylinder diesels like the old canal barges.
 

AlbacoreA

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Does it not depend how you drive it, and what you using it for.

Thinking 10yrs + I think you'll have problems with the turbo, or other things like electrics or bodywork, that will make it uneconomical to fix before the engine. Unless there's some design flaw in it.

Even if the engine failed its going to be small light and thus cheap to replace.
 

newtothis

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Maybe I did not explain clearly, I was not referring that 3 cylinder engines where less reliable, but of the small size of the engine working very hard
The OP was asking about reliability. I'm not sure how you relate to "working very hard" to the engine configuration.
 

roker

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How long will it last in the long term? Does that come under reliability?
The post heading says Life Expectancy
 
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