At RTJ70's suggestion, let's not confuse a general, though interesting, issue with Oldgit's original question specific to the VW Golf 1.4 TSI.
The more general issue - which some people have commented on already in the other thread - is "is there a risk of early failure in a small, highly tuned and (presumably) highly-stressed engine like the VAG 1.4 TSI, as compared to a bigger, less stressed engine?"
I'll reproduce what I said there:
It seems logical that a big, comparatively unstressed engine will last longer and be generally less temperamental than a small highly-tuned - even highly-strung - powerplant. The big engines - even some petrol ones - tend to have plenty of low-end torque which is surely far more useful for the sort of driving that most of us do every day.
Particular favourites of mine have been -
- the B-series Austin engine in my first car, the beloved A50
- the 2.0 Renault engine which I had in a 20TS and two 18 GTX estates in the 1980s
- the V6 24v in the Laguna
- the 1.8 XUD in the Peugeot 205
- the 2.5 TDI in the A4 Avant of blessed memory and the current VAG 2.0 TDI (though I believe both these can give trouble when they get to high mileages).
I've only test-driven the VAG 2.0 TFSI (in an Octavia vRS) and liked that too: I suppose I should reserve judgement till I have a go in a 1.4 - but it does sound as if it may be at its best only at high revs - which isn't what I want.
One comment - which may be the answer - is that it depends whether the small engine is turbocharged or not.
I'm no engineer so I shan't mind being told I'm wrong!
Edited by rtj70 on 27/12/2008 at 19:43
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I'm certainly no engineer either, but as i see it there's no reason why the engine itself should be any more at risk of early failure than a larger easier running motor.
I think the more highly stressed engine would have to be made to a much higher standard, and probably be made of higher quality materials to be able to withstand the stresses exerted on it for much more of its working life.
I do think it may well be more unreliable, not through failures of the engine itself, but to extract the sort of power we are talking of means that the engine will have forced induction of some sort, and probably variable valve timings etc.
That also means that all those extra devices need controlling mechanisms, and goodness knows how many extra sensors etc, which we all know will at some point go wrong, or at least will need careful servicing and monitoring, as some of those parts failing could have catastrophic results.
Would i want a small engine blown and stressed to extreme's to wring the last ounce of power out of it?
No, not because of my admitted luddite views, but i like my cars to be powerful but low stressed (inefficient in some peoples eyes) and therefore very easy to drive in a relaxed manor, thats why i prefer larger engined cars with proper automatics, effortless cruising ability at very low revs, and with the ability to hurl themselves forward instantly but still effortlessly without me having to pre plan the moment into some relatively narrow power band.
If i drive a car thats trying to stall unless i provide lots of revs and drive it hard, then it takes off like a scalded cat all wheelspin and fuss i really don't want it, so give me the larger simpler non turbo motor every time, however a powerful engine in its own right turbo/supercharged (volvo T5 and the like) is a different kettle of fish, and probably gives the best of both worlds, but at the cost of fuel consumption.....cake and eat it?
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Inclined to agree with you GB. Plenty of torque from low revs is my preference too. Can live with or without auto though. Have had many of both but on balance prefer manual. Don't mind a nice auto but certainly wouldn't pay extra for one. Sometimes feels a bit like a ready meal if that makes sense.
I suppose though that I'm quite glad that manufacturers continue to experiment with and develop engine technology. Every so often they will find cleverer ways of configuring them I guess.
Early 16v engines used to irritate me in the way you describe. All or nothing power.
I had an 850 T5 a good while ago. I want to say about '97/'98. It did, as I recall, have a bit of a thirst, 25 mpg was normal or fewer if you were in a hurry. But like some human heavy drinkers it could be the best of company for a while if you were in the mood for it.
To drift back to the topic, I think, until persuaded otherwise, that I probably fall into the traditionalist category for now.
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Agree also, front engine, preferably six or eight cylinders and rear wheel drive. Red line around 6000 with bags of low end torque. Dual exhausts and the window down on a sunny day so you can hear the music. Lovely.... :-)
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Perfect description of my Z3, Captain. Roll on summer - let's be optimistic and remember that the days are already getting longer.....
I forgot the BMW straight-six in my above list of engines. Mine's a 2.2 which gets the balance just right between low-down torque and enough oomph further up the rev range.
Edited by Avant on 27/12/2008 at 23:06
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How refreshing Avant! A smidgen of car related optimism, a sentiment conspicuously absent from this little corner of the internet in recent times. Good man!
I sometimes think that those of us who drop in here regularly are inclined to be caught up in the gloom of the day ( I don't excuse myself either ) The truth is that we come here because we probably like cars a little bit too much. It has almost become slightly sordid to admit that.
Let's have more of it I say!
Parp Parp!
Edited by Humph Backbridge on 27/12/2008 at 23:16
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"front engine, preferably six or eight cylinders and rear wheel drive. Red line around 6000 with bags of low end torque. Dual exhausts and the window down on a sunny day so you can hear the music. Lovely.... :-)"
Sounds like a Maserati 4200 GT Coupe to me!
When I win the lottery ....that body .....that engine......mmmmmmmm!
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Turbo diesel Focus - great for lazy driving with that surge when you needed it.
750cc Fiat Panda. Fantastic fun for the challenge of keeping up with (and surprising) other traffic. How high will they rev?
Horses for courses?
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Horses for courses?
>>
Yup. Make mine a Mustang :-)
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I prefer to have something which I will only rarely stretch to its limits. The fact that it is designed to be capable of giving more than I usually need inevitably means that the way I drive it will give it an easy life and maximise its durability. I apply the same philosophy to washing machines, vacuum cleaners etc.
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I think it depends on the car. Big and lazy in a daily driver for sure (modern diesels have perfect power delivery for daily A to B driving), but something like a Caterham would be wrong without a 7000+RPM, slightly lumpy screamer under the bonnet.
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Just for preference I prefer lots of low-end torque, which applies to quite a few diesels, but far from all of them and also lots of older BMC/BL cars... as well as American V8s... droool!!
As for "big" or "small", it doesn't really matter, BMC/BL had a habit of producing "small" engines with plenty of low end torque, whilst Ford's 1.3s were the opposite - hence we used ford engines in the race engines in preference to BMC engines even though both could be tuned!
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I am in the large and lazy camp, although it is possible, especially with diesels, to run them too light. This probably comes from my marine background where we had to be careful to keep some load on diesels.
In Australia, I had 4-litre straight - 6 Fords. Bit heavy around cities, but excellent machines for long hauls, and essentially indestructible. Cruise control at 2000 revs and the automatic box locked up gave me just under 70 mph and a bit over 30 mpg. If I needed grunt in a hurry, it was there as 2000 rpm was just beginning to work up the torque curve.
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As an engineer, I would say that in theory a big lazy engine will indeed last longer than a small highly stressed one. The big caveat is though that almost all road car engines however small, are very under-stressed. In real life conditions you can't drive any car foot flat for any sustained length of time as you hit corners/speed limits/traffic. Sure you can accelerate hard between bends on a twisty road but how long are you on full power for? 15, maybe 20 or 30 seconds at the outside? Compare that to something like an aircraft or helicopter engine, a rail engine or even a truck engine. These engines spend their time at or near full power for much of their working lives. In this situation you do need a more robust engine design.
A large and lazy engine will always be the easier drive because you can "abuse" it more and get away with it. It doesn't matter if you try to accelerate from 20 in 4th, there's enough reserve to manage it. Hence a larger engine car is generally more drivable than a smaller engined car.
As you have surmised it does depend how that power is delivered. If the engine is turbocharged you can get away with a much smaller block and still have the flexibility. Imagine if all the 2.0TDIs on the roads were overnight 2.0DIs... drop your 140-170HP to 75-80Hp and your 230-260lb.ft to maybe 100-110 at the outside... they'd be a whole lot harder work. Of course the trouble you now have is everyone has a 2.0TDI and so you need more grunt to be able to get past someone who decides to accelerate while you overtake...
In general I'd take a smaller turbocharged engine over a larger non-turbo block in most cases. I've driven the Golf 1.4TSI in 170Hp Super/Turbo form and it was a very impressive block - very linear and enough low down grunt for day to day driving. I doubt someone coming from a 2.0TDI would think it was as instantly quick because it doesn't have the hit in the back kind of delivery but it's certainly not slow.
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I'm currently on 120,000 miles on a 1.6L, 120hp, peak at 6k rpm vehicle and at 90,000 miles on a 1.0L 150hp, peak at 12k rpm vehicle. They both have the advantages and disadvantages, but both seem equally reliable so far.
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Newton explained it years ago.
For every unit of power available for use, a similar unit has to be dissipated within the engine. That's why little high powered engines don't last long, and big low powered one's do.
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big and lazy........
are cars like their owners?
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Westpig... that's :-) from me.
I know I would like a big V6 or V8 petrol for power an torque but don't like the emissions or MPG they come with. I have had some low pressure turbos (VAG ones) and now diesel. I like low end torque and easy/flexible driving.
My brother had a V8 Jeep years ago (now a diesel VW). It was a 5.2l V8 with only about 250bhp! It had lots of torque and did 0-60 is about 8s. But a European 5.2l V8 would be a lot more poweful and efficient - hos did probably 15mpg.
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little high powered engines don't last long and big low powered one's do.
It's all down to the initial design and then the tolerances and materials used.
Even my humble Africa Twin, which is only a humble thuddy V-twin will do 100,000 miles on nothing more than regularly changed mineral oil and valve clearance checks.
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I'm really anything but a motor engineer but this seems like a bit of nonsense discussion. How often do you hear of engines failing because they couldn't take the pressure and blew up or expired? If a car goes terminal it will be because a part failed like a pump or maybe an ECU fried making it an uneconomic repair.
It's not like it's the Enterprise with Kirk asking for Warp factor 20 or some submarine captain demanding 110% power.
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I'm really anything but a motor engineer but this seems like a bit of nonsense discussion.
This appears to be the norm nowadays for the backroom.
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This appears to be the norm nowadays for the backroom.
Oh dear. Somebody else who had a good Christmas.
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If a car goes terminal it will be because a part failed like a pump or maybe an ECU fried making it an uneconomic repair.
I agree. When was the last time any of us saw a car driving along smoking heavily, or with the ends knocking? These two classic signs of a worn engine that's about to expire have all but disappeared.
The last car I heard with knocking ends was a starship mileage C reg Montego 1.6 which came through West Oxfordshire Motor Auctions when I was there about 15 years ago.
In almost all cases nowadays, barring the aforementioned component failure, the engine will still happily pull the thoroughly knackered car to the breakers yard.
Edited by DP on 29/12/2008 at 09:24
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I doubt someone coming from a 2.0TDI would think it was as instantly quick because it doesn't have the hit in the back kind of delivery but it's certainly not slow.
Trouble is, my Octavia 2.0 TDI PD engine can be very annoying on take-off as for a moment there is naff all acceleration then the wallop you describe. Not useful for a quick entrance onto a roundabout or pulling out from a junction.
I'd much rather some more low-down useable power.
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