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Bit confused about engine sizes now

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Posted

Seems they are getting smaller and smaller and my old fashioned rule of thumb about 1800's seems to be a long way in he past. Visited Nissan amongst others at the weekend and their 2014 1.2 Qashqai is the equivalent of the 1.6 2013 model etc.in fact it is quicker and has more hp but surely it would be a lot lighter overall and 1.2? But if you had a smaller van these would probably make a good choice?

The Qashqai 1.2 DIG-T produces marginally more power and significantly more torque than the 1.6-litre petrol engine

Now I am not saying a 1.2 could pull my van but as an example Kia are saying the 1.7 Optima could and checked it towcar.info and says it is a near perfect match at 84%. But a 1.7ltr?

Sooo after that ramble where I am more confused, what are your views and if your are looking at tow cars are you looking at smaller engines or still looking at 2.0 ltr plus

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Posted

Why venture from a 'proper' car? Unless you specifically need 4x4s/SUVs, plenty of modem saloon cars available to tow your caravan?

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Posted

Mark

I know what you mean but it's all down to the technology these days

The cars you have to watch are the small ones the supposedly ECO models

I have just had the displeasure to have had a hire car whilst mine was being repaired

the car a Vauxhall Corsa 1.1 which compared to the Fiat Uno 1000 I used to have was woeful on all counts including economy

BUT

towcars we have a Kia Sorento 1 ( the 1 means Front WD not AWD) at 2.2L dci has less power than the next tow car I have on order a Nissan XTrail nTec 2Ldci

Have fun looking or just get another Sorento - I wish I could but they are no longer on the Motability list due to costing more than the threshold £25000 now

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Posted

I switched from a people carrier to an ordinary estate car 2 years ago - and from a manual to an auto.

Have to say, even though it's over 85% match (about 87% I think) compared to the previous 76% I have absolutely no regrets, The Passat is, in my opinion, an excellent all rounder - great solo around town, excellent on long journeys, huge boot space and a really good tow car.

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Posted

The modern engines are more efficient but the smaller ones are working on their limit where as a slightly larger displacement engine will not be so stressed personally I think around 2 litres is a good place to look.

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Posted

My first tow car was an 850cc mini pulling a Sprite Cadet caravan. 8 cwt in old money.

I think in those days it was 100cc per cwt was the accepted ratio for engine size.

The largest cars in those days were ~1500cc and matched the then largest van sizes. The 85% advice - rule came in about then as well.

We took our mini/cadet rig all around Scotland and down to Cornwall with no problems.

Maurice

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Posted

Perhaps time to think about a motorhome so that you can stop worrying about towcar capabilities.

David

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Posted

The great leaps forward in engine design mean that we are now in the position that was familiar to lucky owner-drivers in he 1930s, i.e. that it is possible to obtain more power and more torque from a smaller displacement. Yes, it takes some getting your head around, but it makes sense really. I think the old rule of >2ltr is outdated.

The only concern I would have in towing with a smaller capacity model (if power and torque were greater or at least comparable) would be the longevity of the engine. So many larger engines run at an unstressed level for most of the time whereas the smaller engines aren't. But then, if the engine has a greater power output, perhaps it doesn't matter how it does it.

I wouldn't worry about it. If a 1.2 has the correct power-to-weight ratio for your 'van, there's no problem.

So says the man who tows at about 62% with a 3ltr diesel!

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Posted

There are some less obvious pluses with pushing a small capacity diesel:

  • The turbo's variable vanes will be switching all the time, by far the best thing to stop them coking up.
  • The DPF will be frequently running at self cleaning temperatures, by far the best to keep that from coking.
  • Arguably the EGR valve(s) will be kept cleaner.

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Posted

We've been looking around at cars today, as Jason has a new job which comes with a car. Has the option to provide his own and charge the company or get one from their list and pay company car tax. There is so much to think about, engine sizes, weights, measures etc - my head is spinning. It was bad enough when we bought our current car. If we get a company car it won't be used for towing, whereas if we provide our own it would be, BUT we'd have to get rid of our current car and buy two cars, one for Jason's work and a smaller runabout for me! Head is in bits!

Wasn't impressed by the Mondeo though even though we've had two in the past.

Good luck Mark, sure you'll find something - is the Sorento dead now, or is this the contingency plan?

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Posted

They're now squeezing a lot more out of the top end of modern turbodiesel engines, which inflates the peak power figure that they can quote.

It isn't a million miles from what happened with petrol engines in the 90s, when manufacturers often doubled the number of valves and reduced the capacity by 200cc to achieve the same quoted peak power figure. It looked good on paper, but you had to thrash the engines so much harder to get the same performance. The gains were in the fact that you could (for example) hit 60 in second, whereas you'd be in third by 50 with the 8v donk. But in-gear acceleration suffered rather badly when you weren't driving like a boy racer, because you had less torque than the larger engine, until you got pretty close to the red-line.

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Posted

I'm with the "Clarkson" school of thought here - power! There was an interesting thread some time ago (can't find it just now) which suggested something like 40bhp minimum per trainweight tonne was a good rule of thumb for choosing a towcar powerplant and I think this a reasonably sound theory. My old 2.5 litre 300Tdi Discovery (nominally 110bhp when new) didn't tow my 1540kg van nearly as comfortably as the 2.0 litre Antara (150bhp) did - and the Antara was a smaller car. Good torque figures are equally important but I think that whatever engine size you might go for an adequate power ratio will make for easier towing.

Just my personal thoughts of course which may well be wrong - but they're mine.

Also, the Antara is a part-time 4x4 SUV which is not that much different to an average estate car really, just a bit taller.

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Posted

A friend of mine has just bought a new Skoda Yeti (facelift model) with the 1.2 turbo petrol engine, cracking car and drives really well, have to admit I was pleasantly surprised at the performance.

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Posted

wine.gif

I'm with Dave on this ...

18 months ago I got rid of my 1800 Focus 115bhp TDCi estate and replaced it with a 1.6 Focus 110bhp TDCi saloon. In theory there shouldn't be anything between them considering the way I drive however my gut feel is that the 1.6 isn't as economical (despite my commute changing and having 30 mile less country road to cope with) and while it's quite nippy at the bottom end it peters out quickly as the speed builds. A full load shows a marked drop in performance too - I love the car, nice and nippy around town, excellent handling, blue tooth, DAB radio and iPod connectivity (£30 pa road fund licence !) but it's certainly a bit lacking in some areas.

Overall it doesn't impact me too much as it's my commuting wagon but if the same issues were to occur on my towcar I'd be gutted !

The best suggestion I can make is to try and find some real world (ie caravanning related) reviews or get around a few forums and ask for opinions from owners of models on the shortlist. Personally I'd be more inclined to the Clarkson approach - POWER !!! or to be more precise TORQUE !

wine.gifwine.gifwine.gif

England.gif

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Posted

Our Vectra Estate 1.9cdti is proving to be a good choice. Plenty of poke, and seats are comfortable. Load space is excellent and fuel economy (which is not rocket science) is better than the Fronty.

We have yet to put a tow bar on it.

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Posted

wine.gif

I'm with Dave on this ...

18 months ago I got rid of my 1800 Focus 115bhp TDCi estate and replaced it with a 1.6 Focus 110bhp TDCi saloon. In theory there shouldn't be anything between them considering the way I drive however my gut feel is that the 1.6 isn't as economical (despite my commute changing and having 30 mile less country road to cope with) and while it's quite nippy at the bottom end it peters out quickly as the speed builds. A full load shows a marked drop in performance too - I love the car, nice and nippy around town, excellent handling, blue tooth, DAB radio and iPod connectivity (£30 pa road fund licence !) but it's certainly a bit lacking in some areas.

Overall it doesn't impact me too much as it's my commuting wagon but if the same issues were to occur on my towcar I'd be gutted !

The best suggestion I can make is to try and find some real world (ie caravanning related) reviews or get around a few forums and ask for opinions from owners of models on the shortlist. Personally I'd be more inclined to the Clarkson approach - POWER !!! or to be more precise TORQUE !

wine.gif:wine:wine.gif

England.gif

Clarkson is right. It is all about power. But it's about the power curve, rather than a misleading peak power figure. The thing that makes conventional diesel engines so flexible is their very flat power curve (thanks to maximum torque being produced as soon as the turbo spins up, but tailing off markedly as the revs rise.) This means that there's often no great power advantage to being in a lower gear, whereas the power advantage is much more pronounced in a petrol engine, which needs to be red-lined to achieve the peak figure, and may be producing less than half of it at sensible engine speeds. A 200bhp petrol engine that hits peak power at 8000rpm is likely producing only 100bhp at 4000, and even less at lower engine speeds. A 200bhp old school turbodiesel is probably producing a minimum of 150bhp for the entire range between 2000 and 4000rpm.

In the absence of a power curve, it's worth looking at both the peak torque and peak power figures, and perhaps even looking at the two as a ratio. An engine with a high peak torque figure relative to its peak power one will be a good, flexible cruiser, capable of delivering the goods without too much hunting through the gears. An engine with a low peak torque figure relative to its peak power figure will need to be thrashed in a low gear to get anything close to maximum potential.

Power is simply torque with speed factored in. Since you're rarely just 'accelerating', and instead are 'accelerating from 30mph' (as an example) torque without speed is meaningless for anything other than hill start ability in first gear.

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Posted

My BMW 5 series estate had a 3 litre diesel and pulled the Challenger 540 with no problem whatsoever. In fact I often forgot I was towing and a glance in the mirror often led to the momentary thought of white van man tailgating me.

I also had a blow out on the van doing 70+ (I know) on the M6. I was towing with a Volvo V70 at the time. I simply took my foot off the pedal and we pulled onto the hard shoulder. At the time it was scary when I thought about it later, the car hadnt moved. I noticed the blow out by the smoke coming from the wheel which had totally disintegrated and had flapwheeled its way through the van floor.

Weight and power is the way............why mess around over the 80% ratio

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Posted

There's no doubt you get more from less as far as engine sizes are concerned. There's an old saying that "There's no replacement for displacement" but it's really not true any more.

On any measure you care to name an engine now is way ahead of the engines of decades ago. More power everywhere, more torque everywhere, more reliable, more economical,

To illustrate:

My Dad always used to say that you needed at least 3 litres if you were going to get an automatic. That was in the 60s.

By the 80s that was down to 2 litres

The last car he bought, in 2010, was a 1.1 litre auto.

Anyone looking back through rose tinted spectacles at old fashioned vehicles is kidding themselves that they are anything other than inferior to modern cars by any measurable criteria

Having said that, I would love a MkII Jag, or an E-type, or .....

You can't measure aesthetics or nostalgia.

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