Well, Alex. I'm just using the figures in all these road test comparisons and the like that they do in Autocar etc (I'm sure you're familiar )

I didn't mean as if to say that diesels were "better", merely that in real world driving they are quicker and more practical for average Joe. I'm not saying that throttle response is as good as a petrol, however compared to.. say 8 or 10 years ago it's worlds away from the old Fiesta 1.8D's.

I think Autocar did a comparison between the Seat Leon Cupra and the Diesel one, and they said although it was a bit more nose heavy, unless you're really going for it the diesel was quicker (both were turbocharged so there's no "omg i hav no turbo!1! problem ) unless the petrol version (which incidentatly had some 60 extra BHP) was on boost, which is likely to happen if any car has that amount of power more...

I mean, I feel like this is a debate not worth having. I'll let the facts and figures speak for themselves..

You can find a direct comparison between diesels and petrols here

I think in all but one or two (forgive me I am tired :shy), diesels will outdrag their petrol counterparts at all the important milestones 30-70, (as I was saying in mah spinoff) 30-50 and 50-70 in 3rd, 4th and 5th.

In nearly every occasion, the diesel will outpull the equivalent petrol..

in the real world, you wont be drag racing the equiv petrol car, anyway. you will be accelerating, at the same speed as everybody else, up to a bit over the speedlimit and staying there, full throttle drag races dont matter a jot in the real world, which is what we are talking about.

Quote from DeKo :

I am indeed not, im just dis-agreeing with ridiculous things your saying. you did try to insinuate that i didnt know what i was talking about because you thought i had never driven a diesel car, when it turns out its actually you.

I never thought you didn't. And so what, you don't need to drive something to know it's quick...!

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I have seen that episode, and IIRC they drove round, mainly in traffic, not trying to see "who would pull away" from each other. they were just staying with each other.

Apart from the arm flailing bit where the petrol one has to change gears

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True, but if you cant tell if your in a petrol or diesel car, you have big problems.

I'm sure if I sat there intently watching the revs, feeling the acceleration and listening for any hint of the rattly diesel engine, then yes I'm sure I could tell. Modern diesels do a remarkable job of covering up their clatter.

Quote :

well, i disagree, as do many people i know, aswell. i would rather have instant response than have to wait, for a tiny bit more power. it may indeed pull a bit stronger, but the difference is hardly noticeable. and anyway, peak torque in the 330d, for example, is at 4k RPM, surely you arent driving around at 4k all the time, are you?

Bullshit, frankly. I guessed peak torque would have come in at around 2,200RPM. A quick google gave me these figures.. 368ft/lb of torque between 1500 and 3000 rpm.. nice?

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i fully agree, i also consider myself an avid reader of various car-related publications, but i value my own opinions more than somebody elses, people can be wrong, you know.

And normally I'd fully agree with you - But perhaps you haven't had the experience they have, driven the range of cars that they have. After all, you said you've driven 3 (rather crap, admittedly) diesels, where as these road tests between them have probably driven thousands of different diesels, and I'm sure that if say, 95/100 of them say "this diesel pulls better than this car", or "we'd suggest the diesel over the petrol <whatever car>", that it won't be the 5/100 that's correct.

Quote :

Im actually not in any hate diesel group, if i did a decent amount of miles (over 15000 a year) then i would buy a diesel car as soon as i could, but i just do not agree with the fact that diesel cars are better for just plain 'driving' than petrol cars, which you seem to think. why do you think most enthusiast cars (MX5, S2000, etc) have petrol engines?

Because people like you wouldn't buy them. :sadbanana

Look at the Fabia vRS, fantastic little car. Has a diesel engine, doesn't really sell all that well! Besides, it's all very well having an 'enthusiast' car, but with potholed roads, sleeping policemen and speed cameras everywhere, I'd rather drive when I have to, to get to A to B as easy and comfortably as a can. Besides, in small hatchbacks (cars the size of the Ford Ka) I agree, a diesel isn't really better.. it's a personal choice. However anything bigger than that probably benefits... say, from the Focus size upwards.

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and your saying I have to change gears more? its pretty damning that a lot (im not saying all, but a lot) of modern small engined diesel cars have 6 gears, while petrol have 5. i think that speaks volumes for the amount of stirring of the gearbox is actually needed.

Amount of gears doesn't equal need to change gears... I'm sure that you don't need to "stir the gearbox" in your Pagani Zonda or the like do you?

Quote :

Lighten up, i was joking because you had'nt replied.

tired sorry.

Quote from DeKo :

in the real world, you wont be drag racing the equiv petrol car, anyway. you will be accelerating, at the same speed as everybody else, up to a bit over the speedlimit and staying there, full throttle drag races dont matter a jot in the real world, which is what we are talking about.

But the point is proven : Diesels do pull better, whether they're "better" for everyday driving is another matter, but for the kind of person that just wants to leave his car in top gear and drive around, it's certainly more relaxing and easier..

Quote from S14 DRIFT :

Amount of gears doesn't equal need to change gears... I'm sure that you don't need to "stir the gearbox" in your Pagani Zonda or the like do you?

You will have to change gear more often in an equivalent diesel car, the powerband of a diesel is so small you won't be able to get away with sticking in one gear in a diesel like you can in a petrol. Often torque gets confused with powerband and people who have never driven one like yourself get the impression that a diesel will produce its torque from idle and be comfortable reasonably quick and economical to drive in such a way (which larger petrols are), couldn't be further from the truth.

I think you still don't understand what throttle response means and how it relates to driving satisfaction and comfort, not to mention how performance figures never give a true indication of what the real world performance of a car will be like.

:doh: They are 'real world performance figures.' :/

I spend the last half an hour or so reading through the comparisons and in the case of the Focus and the Merc, the road tests claimed that the diesels were "more responsive", had "stunning real world performance" and were more "relaxing to drive"

The Tiguagaugaugauananau and the Yaris would both up for the petrol, mainly down to the value thing, because diesels are more expensive to buy. The petrol engine in the Yaris was better, and I think in the Tuguguaugauanuannaan was breathless and something else which I've forgotten..

I guess it really all boils down to a) the type of car and b) what you're 'gunna use it for.

But you're right, Alex. You do have to use the gears more on a diesel car (although I only find this an issue at really low revs, say under 1,300 or so.) It's two completely different ways of combustion and it's probably fair to say only a numpty would get out of one and try to drive the other in exactly the same way.

True, for an out and out thrash petrol is the way to go. I'm not debating that, but as I said, where can you use the performance.. certainly not on the way to work.

Trackdays? Rent an Elise for the day so it's not your tyres, brakes and engine you're giving a hard time..


As said, this is all from these various reviews and what-not, but yeah.

Quote from danowat :

Nice constructive post from someone who comes from a place where a pickup is seen as acceptable transport

Pickup / Ute


Not the same.

Quote from S14 DRIFT :

:doh: They are 'real world performance figures.' :/

You can't measure how a car will be in the real world on a test track, they're still acceleration figures from full throttle acceleration between a certain speeds and show nothing about responsiveness.

Quote :

I spend the last half an hour or so reading through the comparisons and in the case of the Focus and the Merc, the road tests claimed that the diesels were "more responsive", had "stunning real world performance" and were more "relaxing to drive"

Where?

I prefer diesels, simply because of the way they drive, in the same way I prefer v-twins to revvy 4-pots

I have driven both diesels and petrol. I would say by far a petrol car has better throttle response over the diesel. The diesel had much more torque in the lower rpm ranges (afterall thats what diesels are designed for), but I was constantly changing gears to get anywhere because the powerband was so small compaired to a petrol.

Diesels were designed in trucks for a reason, and it's not for their crisp response...

Dan, compairing V-twin to a diesel?

I didn't drive the Fiesta fast, but even just going around town it felt horrible to drive - it felt totally unconnected to the road and was uncomfortable as hell to boot.

EDIT - This was a 55 Fiesta not the older ones...

So you staying with the proton yet? There is nothing wrong with it, you know how it was driven and the insurance is cheap. Not to mention you get ok gas milage with it.

Quote from Christopher Raemisch :

but I was constantly changing gears to get anywhere because the powerband was so small compaired to a petrol.

Dan, compairing V-twin to a diesel?

The opposite to my experiance, in both twins and diesels it's easier to keep the vehicle in a higher gear, rather than have to drop down into a low gear to get it going again.

My car makes plenty of power to get it moving from 1500rpm, all the way up to the heady heights of 4500rpm (LOL), but thats more than enough span for my driving style on the road.

My v-twin works in a similar way, however, it's got a bit more up top, I can ride it easily at revs less than 3000rpm, and it makes a SHED load of power from 3000rpm all the way to 10500rpm, which compared to my CBR, which would struggle under 8000rpm.

Quote from Jakg :

I didn't drive the Fiesta fast, but even just going around town it felt horrible to drive - it felt totally unconnected to the road and was uncomfortable as hell to boot.

EDIT - This was a 55 Fiesta not the older ones...

Have to agree with you on this one, drove a 2008 fiesta once for a driving lesson, worse car I've ever drive, and the lesson was crap too I vow never to drive one of those again

Quote from Blackout :

But isn't the diesel turbocharged while the petrol isn't? You think diesel would still win if both or neither had a turbo...no you wouldn't.

Quote from S14 DRIFT :

But you can't say that, Blackout.. it's an unfair comparison to make.

Nearly all diesel engines are turbocharged, it's just how they work. Irrelevant point to make. They turbocharge them because if unturbocharged, they'd be so slow and woeful no-one would buy them.

That's a 1-0 for Blackout. I fully agree. A modern diesel needs a turbo in order to be as fast as a normally aspirated petrol engine.

Responsiveness is not the amount of power available at a certain rpm, but the time it takes from stepping on the throttle to delivering that amount of power. Correct me if I'm wrong.

Quote from hrtburnout :

That's a 1-0 for Blackout. I fully agree. A modern diesel needs a turbo in order to be as fast as a normally aspirated petrol engine.

Responsiveness is not the amount of power available at a certain rpm, but the time it takes from stepping on the throttle to delivering that amount of power. Correct me if I'm wrong.

throttle response and the general responsiveness of the engine are 2 different things. you can have amazing throttle response, but still not go anywhere.

Oh dear. So many untruths about diesels here. Clearly few in this thread understands how they work (and yes, one ofmy fingers is pointing at your Jamie)...

Now this has gone to typical diesel vs. petrol willywaving battle of nerds.

Well, all I'm going to say that I prefer diesel in big engines, in trucks, boats, trains and tanks.

I have driven different diesels, a bit shortly I admit, but enough to give an impression of the car. The worst one (if we talk about small cars now) being an older VW Transporter, a driving experience I wouldn't wish even for my worst nemesis. Yes, it wasn't a TDi so it didn't really go anywhere. But then, a newer Transporter TDi 4motion is pretty much the opposite and if I dare to say, quite fun and quick for a van. But then, it has 130 horses, so it should be.

Other positive driving experiences with diesels I've had include a Toyota Avensis, VW Passat and Golf TDi, and Land Rover Defender which wasn't that bad engine wise either. That's pretty much all diesels I've driven if you don't count trucks. I'd say there isn't much wrong with them other than you might need more gear changes and the sound. But I wouldn't buy one myself either. While diesel is still cheaper than petrol over here you still need to do more kilometers per year to have any benefit over petrol I think. Of course if I had my own fast food joint and access for free used cooking oil then I might consider.

edit. Just realised that all of the "positive" diesel experiences I've had have been in the more powerful models, which might have been the reason they were any fun at all. The most powerful petrol drive must been 115 horses. Or if by power to weight probably Smart Brabus.

edit2. Back on topic actually.

Yes, Jack if you are considering a diesel, don't buy a old lower range model with no turbo as you will hate it. :P

Diesels are meant to be run within a very small rpm range. Their powerbands http://www.diesel-cold-air-int ... -results-Duramax-Dyno.jpg. Diesels are meant to resist changes in RPM over differing loads. Hence why they are compression driven.

Diesels are not meant to 'be run through the gears' and accelerate quickly. They tend to have larger, and heavier engines and internal components, to handle the massive amounts of torque they produce, part of the reason why they have such a low max RPM.

Will diesel get you better drivability? Maybe if you enjoy shifting all the time while accelerating because they are peaky with short powerbands. Will you have to shift going up hills? Probably not because this is what a diesel is designed for. Will you have to shift to pass someone on a single carriageway? Probably, when you run out of RPM. You will not have to shift to get into the powerband because you are probably already cruising in it.

If diesels did have such wonderful and wide powerbands what would be the need of having 16 or 32 gears in a lorry then? Surely if there was plenty of power available through the whole rpm range that 1/2 that would be needed? Don't tell me these diesels are different than car diesels, both run the same fuel and operate under same laws of physics...


FTR the pug had a powerband of about 1500. Anything before 1500 was useless, and while it did have a rev limit of 4500 the 1500 leading up to it was useless and flater than the bonnivlle salt flats. This gave me a whopping 1500 RPM to work with...

Now my petrol car.. I get max torque at 2200, sooner than the diesel in fact, My torque doesn't even start falling off until 4400 (all 250ft-lbs) by then I am well into my power which starts showing itself at about 3500. Max power is at 5200. Then from there they both slide off to a 6125 redline.

If I do my math right that leaves me with a powerband nearing 4k. Almost the maximum rpm of virtually every diesel.

Newer diesels will probably have a little larger band, but not 4k...

Newer diesels generally have narrower powerbands as emissions and noise control techniques squeeze it down to the tiny area of rpm they work in. Which is why they have a million gears these days. They are also worse for the planet, but people seem to ignore that and trust the contrived taxation system as a reliable guide for actual 'greenness'.

ILY too Tristan..

I still maintain diesels are FTW.

Quote from ajp71 :

Where?

I can't point out exactly which line, but it's around the "midway" mark of the review for both cars.

Yeah, yearly taxation does now favor diesel in a way over here too as it's based on CO2 values, and I guess as diesel takes less fuel it will make less CO2. Which in any way probably is irrelevant to anyone as more hevier gases like methane are released from the earth all the time, but that is too complex for people to understand and you can't put a tax on it.

But modern diesels should be cleaner if you mean small particle emissions (or whatever they are called in English) than just few years ago.

And lorries having plenty of gears, well, you also need to consider that they easily weight 10 times more than a normal car with some load, but only have 3-4 times larger engines. I know the math might not work like that, but just pointing out that they need to pull a lot of mass with relatively low power to weight ratio. If you don't have a heavy load you only use half of the gears anyway, so it's there to ease thing up.

Not sure if I made any points there..but mehh, I still like truck engines. :P

And 48 liter twinturbo V12 tank engines...mmmm

Quote from S14 DRIFT :

I still maintain diesels are FTW

That's only because you don't know enough about diesels.

Well my Mum drives a Toyota Rav4 diesels which I've driven (sorry Deko, I lied).. various family members and freinds have other diesel cars but since I don't often go in them it's hard to make a judgement.

The Rav4 pulls like a train, will do 45mpg and makes a fair bit of dug-dug-dug while it's doing it.

I'm sorry, but owning some agricultural diesel vehicles doesn't qualify you to judge diesel's worths. Just like owning a hamster doesn't qualify you to discuss the merits of particular gene structures or protein growths.

Just think how much quicker, quieter and greener that car would be on the road with a gasoline engine. It might be less good at pulling up tree roots because of the high peak torque figures with suitable low-ratio gearing, but at road speeds you've got nothing but horrible compromises.

Don't be mean about our Rav! It's a lush little car. Hairdressers car you.