The "which sort of engine" dilemma

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#2187508 26-Feb-2019 12:57

Coil:

I don't know many makes of cars where literally every single diesel they made was prone to head issues.......

About 20 years ago there used to be a saying don't buy a diesel car with an "M" in the name.

I think one of the problems with diesels is the higher internal combustion pressures mean the engines need to be heavier to withstand the internal pressures. I guess manufacturers are balancing strength against weight and weight is winning out.

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#2187520 26-Feb-2019 13:12

Coil:

Well with Toyota you now need to press a button and sit idle for 30 minutes while it starts smoking like it is on fire.. Or take it to the stealer.
https://www.toyota.co.nz/globalassets/documents/brochures/2016/quick-guide-to-the-diesel-particulate-filter-dpf.pdf

Sorta OT, but this is something that only needs to be done every 80,000-100,000km or so, dependent on driving. They only have added a switch because people would just ignore the warning light telling the driver to that it was ready for auto regen and to keep it at operating temp conditions (for high exhaust gas temps). And then cry murder when they had to replace a $5000 DPF.

Excessive idling (waiting in traffic) or short a/b trips will bring that figure down though. But the same can be said for any car though, most OEMs will state a half service interval for these sort of conditions (7,500km instead of 15,000km).

On topic, one thing you will find though is that cars that can take advantage of higher octane fuel may run more efficiently on it. For instance, I have recently switched to BPs 98 from Zs 95 for my Mark X, and I find there is a noticeable bump in fuel economy. And it drives smoother as well. Depends on the sort of compression and injection setup the motor is running though, YMMV.

You will find smaller displacement turbo motors becoming more prevalent as manufacturers work towards meeting increased emission standards. Turbos work well for emissions, as they work more efficiently with higher exhaust gas temps and in turn help the motor burn more efficient mixtures. As well as a 1.2l turbo can usually match a 1.8-2l power and torque output figures. There IS a replacement for displacement.

Really it comes down to are you planning on keeping this car forever or just the warranty period. A modern car is a complex machine and a turbo-charged motor, even more so. Issues under warranty = not your problem. Outside of that, there is a whole lot more expensive stuff to possibly go wrong on a turbo-charged motor vs NA.

Some OEMs such as Toyota do extended warranties after the original warranty expires, so as long as the car has a good service history, keep that sucker covered.

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#2187572 26-Feb-2019 14:14

Im going to chime in and address some of the misinformation around the 1.2 Turbo comments.

Wife has a skoda fabia 1.2 turbo.

By no means is the 1.2L engine stressed in any way, the manufacturers build these engines like this to behave more like a diesel. In other words low down torque which is where the majority of road users sit in the rev range and actually want the power.

As for servicing you should check each brand. The 1.2L turbo in the wife's car only needs servicing every 20,000 or 2 Years (whichever comes first)

Typically fuel useage and engine displacement can be equally attributed to how much low down torque is produced and needed to push the car along the road.

I would be willing to bet that real world comparisons of the 2L vs 1.2T would show a different picture in drive-ability and fuel consumption.

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#2187596 26-Feb-2019 14:48

ratsun81:

Im going to chime in and address some of the misinformation around the 1.2 Turbo comments.

Wife has a skoda fabia 1.2 turbo.

By no means is the 1.2L engine stressed in any way, the manufacturers build these engines like this to behave more like a diesel. In other words low down torque which is where the majority of road users sit in the rev range and actually want the power.

As for servicing you should check each brand. The 1.2L turbo in the wife's car only needs servicing every 20,000 or 2 Years (whichever comes first)

Typically fuel useage and engine displacement can be equally attributed to how much low down torque is produced and needed to push the car along the road.

I would be willing to bet that real world comparisons of the 2L vs 1.2T would show a different picture in drive-ability and fuel consumption.

I Eek'd twice in that. As an ex VW employee, all I'm gonna say is do it every 10,000.
And the 1.2L is also quite a lot smaller with a lot lighter duty components that if worked hard will wear out faster. Thats a fact.

And as you say re peak power and so fourth, the time it takes for your turbo to quit lagging the 2.0 N/A will be out the gate and down the road. Don't forget most turbo engines are only at peak efficiency when on maximum boost and to make boost you need to dump a lot of fuel in. Sure a small petrol turbo is great at a constant load, but a larger N/A will beat it if the load is varying and the engine is not constantly labored.

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#2187597 26-Feb-2019 14:48

I have a 2.0L turbo on a 1600kg vehicle that puts out 221kw and climbs the steepest hills fully loaded at 1800 rpm.

It does 8L/100km in long distance travel. Town travel - never estimated.

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#2187602 26-Feb-2019 14:53

The internet is full of videos like this, he seems to explain ok.

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#2187623 26-Feb-2019 15:24

jamesrt:

Thank-you for all your input.

It sounds like my reservations around the 95 octane turbo are not entirely unjustified, which helps narrow down the selection criteria!

I think you can safely say that your question is inaccurate - it is not which sort of engine.

Rather, it is which engine and which car.

I think you can have really good small turbo and really bad big NA, and vice versa.

Now, good depends on what you want. A high power engine may not be fuel efficient. A fuel efficient engine may give you little power. Then there are the hidden gems that give you truckloads of power and is also fuel efficient!

And you can't generalize.

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#2187637 26-Feb-2019 16:03

Coil:

ratsun81:

Im going to chime in and address some of the misinformation around the 1.2 Turbo comments.

Wife has a skoda fabia 1.2 turbo.

By no means is the 1.2L engine stressed in any way, the manufacturers build these engines like this to behave more like a diesel. In other words low down torque which is where the majority of road users sit in the rev range and actually want the power.

As for servicing you should check each brand. The 1.2L turbo in the wife's car only needs servicing every 20,000 or 2 Years (whichever comes first)

Typically fuel useage and engine displacement can be equally attributed to how much low down torque is produced and needed to push the car along the road.

I would be willing to bet that real world comparisons of the 2L vs 1.2T would show a different picture in drive-ability and fuel consumption.

I Eek'd twice in that. As an ex VW employee, all I'm gonna say is do it every 10,000.
And the 1.2L is also quite a lot smaller with a lot lighter duty components that if worked hard will wear out faster. Thats a fact.

And as you say re peak power and so fourth, the time it takes for your turbo to quit lagging the 2.0 N/A will be out the gate and down the road. Don't forget most turbo engines are only at peak efficiency when on maximum boost and to make boost you need to dump a lot of fuel in. Sure a small petrol turbo is great at a constant load, but a larger N/A will beat it if the load is varying and the engine is not constantly labored.

If a manufacturer specifies a service interval then they need to back it up if its insufficient then the mass breakages that would occur will be noticed quite quickly. Either way warranty and CGA applies.

I think you should consider that ALL engines if overworked will wear out faster so blanket statements like this really do need a bit more thinking.

Any vehicle that has an engine underpowered for the chassis will be labored and cause higher fuel consumption, suggesting that a 1.2 turbo engine with more useable torque output than its 2L counterpart is over stressed is not correct.

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#2187645 26-Feb-2019 16:12

ratsun81:

Im going to chime in and address some of the misinformation around the 1.2 Turbo comments.

Wife has a skoda fabia 1.2 turbo.

By no means is the 1.2L engine stressed in any way, the manufacturers build these engines like this to behave more like a diesel. In other words low down torque which is where the majority of road users sit in the rev range and actually want the power.

As for servicing you should check each brand. The 1.2L turbo in the wife's car only needs servicing every 20,000 or 2 Years (whichever comes first)

Typically fuel useage and engine displacement can be equally attributed to how much low down torque is produced and needed to push the car along the road.

I would be willing to bet that real world comparisons of the 2L vs 1.2T would show a different picture in drive-ability and fuel consumption.

Either Skoda is brave or wants to break your car.

I sure hope your dealer used Skoda's long life oil in there. Even then, it depends on the driving style. Lots of city hilly driving, will make the oil degrade faster. Once the oil loses its lubrication ability your engine and turbo is toast. Unless it's a toyota corolla or hilux, then they probably run fine on sterile spit.

ratsun81

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#2187656 26-Feb-2019 16:29

Batman:

ratsun81:

Im going to chime in and address some of the misinformation around the 1.2 Turbo comments.

Wife has a skoda fabia 1.2 turbo.

By no means is the 1.2L engine stressed in any way, the manufacturers build these engines like this to behave more like a diesel. In other words low down torque which is where the majority of road users sit in the rev range and actually want the power.

As for servicing you should check each brand. The 1.2L turbo in the wife's car only needs servicing every 20,000 or 2 Years (whichever comes first)

Typically fuel useage and engine displacement can be equally attributed to how much low down torque is produced and needed to push the car along the road.

I would be willing to bet that real world comparisons of the 2L vs 1.2T would show a different picture in drive-ability and fuel consumption.

Either Skoda is brave or wants to break your car.

I sure hope your dealer used Skoda's long life oil in there. Even then, it depends on the driving style. Lots of city hilly driving, will make the oil degrade faster. Once the oil loses its lubrication ability your engine and turbo is toast. Unless it's a toyota corolla or hilux, then they probably run fine on sterile spit.

Its in the service manual and the dash does alert when its time/due.

From what i can gather there is only one oil type specified for these so i would hope the skoda dealer is using the correct spec oils.

Driving type does matter, on my diesel with long life service and shortish trips being most of its driving i probably only get to 14,000 before the oil quality sensor decides its service time.

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#2187704 26-Feb-2019 18:27

ratsun81:

....., suggesting that a 1.2 turbo engine with more useable torque output than its 2L counterpart is over stressed is not correct.

I think you are misunderstanding the use of the term stressed in this situation. A smaller capacity engine producing the same or more power than an engine with 66% more cubic capacity is by definition more highly stressed. More power has to be produced per CC and usually that engine will run hotter and will have more wear.

In your 1.2 litre engine the turbo is increasing the effective compression ratio in order to produce the extra power compared to a normally aspirated 1.2 litre engine. When you increase the compression ratio you increase combustion temperatures. Increased temperatures - increased wear and tear. You don't anything for nothing.

Under normal circumstances a bigger engine producing the same power as a small one will give a longer service life.

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#2187726 26-Feb-2019 19:42

ratsun81:

Its in the service manual and the dash does alert when its time/due.

From what i can gather there is only one oil type specified for these so i would hope the skoda dealer is using the correct spec oils.

Driving type does matter, on my diesel with long life service and shortish trips being most of its driving i probably only get to 14,000 before the oil quality sensor decides its service time.

Ah that'll be fine if it has an oil quality sensor. As it's not just accelerated oil degradation as a real world problem, but you can also get water ingress over time "diluting" your lubricant.

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#2187735 26-Feb-2019 20:57

Do any of these engines have sensors as such or just run time and start counters with short trips earning more penalty points than longer trips?

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#2187736 26-Feb-2019 21:02

Bung: Do any of these engines have sensors as such or just run time and start counters with short trips earning more penalty points than longer trips?

I don't know what Skoda uses but I search oil quality sensor and sure enough they exist

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#2187739 26-Feb-2019 21:22

Bung: Do any of these engines have sensors as such or just run time and start counters with short trips earning more penalty points than longer trips?

They're not just timer based. The use a much more in-depth analysis of duty cycle which can be determined by multiple sensors from the engine and transmission, fuel injection system, engine temperature, speed sensors etc etc.

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