L'escargot have you ever driven a modern diesel?
Cars and trucks.
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Cars and trucks.
fair enough, in which case we must agree to differ. :-)
I must say I wonder whether the difference is really between diesel and petrol, or whether it is more due to forced induction? A friends Leon Cupra had the same effortless low down shove as a decent diesel, and was the 1.8 T petrol. Now some of the new direct injection petrol turbo's are getting near to 40 mpg, petrol makes a lot more sense at high mileages (although I am sure I read somewhere that these suffer from similar particulate issues as diesels, so perhaps not the magical solution).
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Precisely. Diesel torque is within real driving ranges, and is so easily accessable. With the exception of some big petrol engines and turbo petrols (which are now striking a great power / economy cycle lately), natural aspired petrols dont have that luxury unless you gear down a notch or 2.
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Only my tuppence.
Depends entirely on what sort of vehicle you are looking for, there are countless variables, and a lot depends on budget.
In practice, a lot of engines, petrol and diesel, are very low on initial torque without a trailer attached and many modern vehicles seem to have quite high first gear ratio, which will not help a great deal when you are doing a hill start in Devon.
A lot of newer diesels are completely hopeless below 1800 rpm and would be a pain to get the van moving, mind you some petrols are no better too.
My own opinion of diesels is, to ignore the bhp and concentrate on torque at the lowest rpm possible, especially as a towing vehicle.
Maybe if you could say which vehicles you are intersted in, or give an idea of budget, new/used, preferences in manual or auto or indeed automated manual, and whether you have a desire for 4 x 4 or want the lowest VED possible the very knowledgable people here could give a considered opinion.
Hope i don't come over as being funny, i'm not meaning to, but its like comparing a BMW 530D with a focus petrol as tow cars, one will be superb, the other will struggle, not knocking any vehicle here, its horses (or lbs ft) for courses.
Edited by gordonbennet on 02/06/2008 at 15:09
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We have a freelander td4 and it tows really well. It just seems a bit ott for going backwards and forwards to work and the supermarket. And the kids walk to school so can't even use it for that!! Budget is probably around £7k, would like decent mpg and got to suit family of four plus associated gear and dog. Probably manual but not set in stone. OH isn't keen on Fords for some reason. Looked at passats, 407 sw, touran.
Sorry, but ratios and torque don't mean a huge amount to me! Do notice that the Freelander is very easy to stall though(not just me either).
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Just my thoughts, you've got a vehicle thats good for towing, plus its got the bonus of 4WD for when you get your van on the green stuff.
Why not get either a steinbauer (or similar) tuning box or get remap of ecu if preferable or possible. Both about £400 mark with about 20% increase in torque, but check with your insurance co first, they may load the premium/decline insurance.
Either would give you significant gains in low speed torque, and make the vehicle a lot more difficult to stall, plus make the general driving of it much more pleasurable.
I understand what you are saying about ott for normal use, but if you look at it logically, its only a fraction heavier than the other vehicles you've looked at, its just a bit higher, probably shorter, just as good co2 with the BMW engine and a better bet for your caravanning. Plus the freelander laughs at all those speed humps and holes in the road.
No wheelspin pulling away in the wet whilst towing, try that in some of the others.
Have you tried a freelander auto by the way, thats very nice to drive IMO, but i think diesel auto's (proper auto's) are the bees knees anyway, so i'm biased.
Out of your alternatives, i drive the 407 quite regularly, its ok , but unless you go for the 136, you'll find not a lot of initial torque for your towing activities, unless of course you go auto. Can't speak for the other vehicles.
Your vans not a toy at its given weight, nice to have a vehicle in charge of it.
By the way, proper kids able to walk to school, now thats amazing. Well done.
Good luck in your choice.
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Your dislike of them appears to be boundless ........
On the contrary, I absolutely love diesel engines. In their various forms ~ industrial, marine and automotive ~ they have either directly or indirectly provided me with gainful employment for most of my working life.
......... your claim that they have less torque than an equivalent petrol
I've never said that a diesel engine's output torque is less than that of a petrol engine ~ I'm completely and utterly aware that for 2 similar capacity automotive engines a diesel engine will have a higher output torque than a petrol engine. But what most people appear not to realise is that it is torque at the driving wheels that matters, not engine output torque. And because diesels are higher geared than petrols it reduces the torque at the driving wheels proportionally. I just wish manufacturers would quote torque at the driving wheels (preferably in all forward gears) and then all the common (and popular) misconceptions might disappear.
It's undoubtedly true that a petrol will generally be quicker for a 0-60
The reason that acceleration times are significant is that the torque at the driving wheels (which is the thing which really matters) is inversely proportional to acceleration times.
Edited by L'escargot on 02/06/2008 at 20:09
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I am a caravanner (OK, lay off!!) and reckon that diesel is much better having towed with both petrol and diesel. My only direct comparison is when we switched from a petrol Renault 18 to a Cit BX of very similar bhp (that's a while ago!!). The BX was very superior - both in terms of ease of driving and economy. We have stuck to diesel since, especially since diesel is much cheaper on the continent - (well it was!). The modern diect injection diesels are even better (we now have a Xantia Exclusive HDi which does over 35mpg when towing) because they pick up from very low revs - our older Xantia was a TD but was pretty useless below 2000 revs when the turbo suddenly kicked in - but it was still a good tower.
Another thought - if petrol was better for lugging big loads , how come there ain't many petrol trucks around?
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For towing work, where the engine is more likely to become bogged down and labouring than normal motoring, a different torque characteristic is required.
What is needed is called back up torque - this is in a way similar to GB's suggestion of a good torque characteristic at low speeds. Back up torque is when you have a consistently falling torque as engine speed rises.
As the vehicle begins to climb a hill, and engine speed falls, the engine's torque output rises, and there's a better chance of equilibrium being reached without needing a down-change.
Shifting the torque peak to low engine ravs can be done with petrol engines, by changing the valve timing. This is one of the functions of the different camshafts which are used in commercial petrol engines which are otherwise similar to road going engines.
Obtaining back up torque always costs outright power, but does give a better towing characteristic. 0 - 60 times are almost irrelevant in this application.
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I haved towed caravans for more years than I care to remember. Diesel everytime for me. I did use a 3ltr 24v but too thirsty 13mpg towing & still ran flat up hills. 2.2tdci storms up hills even with 1600KG on the back & get between 26-30 depending on how hard you tow. I have never had a diesel bog down towing or get stuck on a hill except for 825td Rover but that was old technology. I tow over the Alps with no probs in the TDCi & I have never had a clutch. Often go to Europe for a month & cover 5-6OOO miles.
I say diesel.
IJ
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>>I say diesel.
>>IJ
Yes, likewise - I forgot to say that older turbo diesels used to supply exactly the characteristic I described. The torque would fall with rising rpm, producing a very flat power curve, sacrificing ultimate power levels for excellent tractability.
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