Head vs Heart

obi_waynne

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My head is telling me that Diesels are great, economical powerful torquey and fantastic. My heart is telling me that I want a petrol?

Am I alone? Can you help convince my heart that Diesels are a good idea? (Or perhaps you could help my heart convince my head that I'm better of with a Petrol!)

What is it about Diesels that is preventing me from making the jump!
 
Noisy days are gone Pgarner... you can go for your head Waynne, with a turbocharged engine...but I suggest to follow your heart, it'll keep disturbing you...:D . Besides I think petrols are more friendly to modifications...
 
You could always take a test drive and see whether your heart will allow the derv route. Unless you're after top dollar machinery like the sueprcharged Jag XF I think you'll get more performance per £ with derv.
 
f you're not concerned with mpg then go for a nice big petrol. If mpg is a concern but you still want some grunt, get a diesel and remap it.

Love my diesel but once I have the pennies it will be swapped for something automatic and V8
 
but its the sound you get from a petrol v8.exhaust vroooooooooom.even on a small engined petrol with a nice performance exhaust.

I don't agree with you on that front when it comes to 4 cylinder diesel engines. The supercharger(s) can make them sound like gas turbine engines under firm acceleration with the hysterical scream they emit and they don't even need dump valves.
 
having had many diesels, i always go back to petrol, it's all to do with the power delivery. I just don't like it, even in a BMW 330, bags of torque but no rev range, and you still have that diesel exhaust note.
 
I'm a firm petrol fan.. again because of the power delivery and rev-range. I've had and driven numerous diesels, but I always end up coming back to petrol.
 
Yep, you've got to love the midrange clout that turbo diesels offer,

and diesels do sound good these days especially with a performance pipe, go on the Milltek website and find the A5 3.0 TDI clip on there, you'll be presently surprised, and the Astra 1.9cdti on there as well
 
Don't suppose they do a dual fuel petrol/diesel option? ;)

Not yet!

Seriously though, you should consider derv with an open mind, especially if you're going to buy new/nearly new with manufacturers warranty.

I think that the current diesel technology is beyond reproach in performance, refinement and FUEL economy terms. But it's quite immature, especially considering the very prescriptive emissions control systems.

With a new car you can stick to the 30,000+ mile service intervals. It's this which attracts fleet operators. But if you're buying new and plan to keep the car 10 years, let's say, then I'd advise you service much more often. Let's say no more than 20,000 or one year between major services.

Common rail diesels (my 2002 model year 2.2 HDi was one of these) deliver stonking performance in stock tune. The fuel economy isn't bad. Note that I'm not saying it's sensational either.

The midrange thump is addictive and all the time engine desingers are getting cleverer, the usable rev range gets better. One thing diesels are not good at is pulling from sub 1000rpm, despite what others say. A petrol engine will do that quite happily, even if it does it slowly at first.

Long term running costs can mount up though. As I said, the technology is still green and wet behind the ears, despite its spirited and muscular on-road performance.

Basically I suggest that you go and try a few diesel models alongside similarly priced petrol ones and see which you'd rather drive day in, day out.
 
I have seen technology where engine burn petrol and diesel together and the results have been astonishing, they burn at different ratios depending on engine load etc,

I've been looking for the article on the Internet and haven't found it yet,

I'll let you guy know as soon as possible
 
Stick with petrol if you don't do man miles Waynne. Diesel as a fuel is more expensive to buy in the first place, and usually diesel varients are more expensive than their petrol counterparts. Thus, unless you do a lot of miles you might find running a derv more expensive.

Not to mention considerably less fun than a turbocharged petrol car. You get a big grunt of torque for about 2k rpm them it's all over and you have to change up. Get a good petrol turbo car and you'll get a big shove right through the rev range.

Also, if its Audi's you're looking at, they do sound like tractors. As do Fords diesel engines. They are without a doubt noiser than any petrol engine I've heard. BMW's offerings though are brilliant in terms of noise and refinement.
 
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Diesel all the way, you know it make sense,

TN has never owned a good diesel so wouldn't know ;P


He would and he has.;)
I've had a few Diesels actually and i've had a fair few Courtesy cars that was diesel this year alone. All being more or less brand new.
yeah they got the Torque but as already said no rev range at all. Pointless imo.
 
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I dunno they're all that bad. My 406 was redlined at 5300.

OK, it's not as high as the 7500-7600 in a decent petrol engine but still usable.

I'd still take diesel for my liking of mid range slam.
 
That's not entirely true ma,

My old 306 will pull from about 2500 rpm to 5k easy, it just depends on what you buy,

I do like petrols but they are a bit "ordinary" in the tuning world, time for something different I think
 
My old 306 will pull from about 2500 rpm to 5k easy, it just depends on what you buy,

Lol I think you've just proven my point. My GT will pull hard from 2k to 6k, runs out of puff after that due to the standard turbo but it will still rev to 7300rpm, you'll have changed gear three times by then :lol::lol::lol:
 
Not really, granted my current gearbox is rubbish but with a different gearbox ten I think things will change, 1krpm isn't a great del difference and if I install the piper cam then I'll be able to make power to 6.5k with diesel torque that would make for one quick car...
 
No point arguing, because I'm right lol. Greater lift and duration won't increase your powerband, it'll just shift it higher up the rev range and possibly out of the efficiency range of your turbo (depending on which you use of course). What you're essentially trying to do, is turn it into a petrol.

1500rpm isn't a massive difference though, but I was being modest. A difference of 2300rpm in every gear however is a pretty big difference.
 
I dunno they're all that bad. My 406 was redlined at 5300.

Yes but it's not really about the redline, you've had your peak torque by about 3000rpm then it's just a fat lot of nothing especially with the relatively small turbos dervs roll out of the factory with. A petrol car will pull and pull hitting its peak power around 5000rpm or after.
 
Yes but it's not really about the redline, you've had your peak torque by about 3000rpm then it's just a fat lot of nothing especially with the relatively small turbos dervs roll out of the factory with. A petrol car will pull and pull hitting its peak power around 5000rpm or after.

I know all this. I just happen to be fond of the midrange slam. I also like leggy revvy petrol engines such as in the E39 I have at the moment but in general I find that diesely 1500-3500 wallop more useable.

Yet I'm not a great fan of the VW PD 1.9 units for the reasons stated here. It's all over by 3000rpm. There are better 4 cylinder diesels on offer.
 
Bigger torque and longer ratios will make up for it without a doubt but my car is heavier that a punto though

It does in the case of some of the more recent common rail engines. Funnily enough the biggest weakness I find with modern diesels is not the lack of 'revability' but more the fact that they really don't wanna know at idle speed.

I think this might be due to the current fad with modern diesels for lowering the compression ratio to reduce the clatter at cold idle. Even my 406 (2002 year model) was only about 19.5:1 compared to the more usual 22-24:1 ratio. Once under way the turbo sorts things out nicely but there is that latency below about 1300-1400rpm so you have to be pretty methodical with your choice of gears. Most petrols will tolerate being 1 cog too high at low speed.

The old 1.9 litre NA diesel Seat we had, however, pulled superbly from idle. Of course, things went downhill thereon in.

It is becoming more subjective all the time, and diesel engines have had massive investment made in the last decade. Blimey, even I've taken a liking to the things and I was the original diesel hater.

It is largely down to personal preference now regarding what you choose to drive.

Let's not kid ourselves, however.

No car is cheap to run anymore. The governemntal rules have made sure of this.
 
I'd quite like to fit the GTI6 gearbox to my 1.9, I know it's fits on but the ratios are way out,

If I could some how equip it with a longer (much longer) final drive then I could make a very entertaining car...
 
I thought diesels had longer gear ratios than petrols ive driven my nan vauxhall zafira 1.9 cdti 120bhp and it goes quite well you really feel the turbo boost in 1st 2nd and 3rd but only revvs to about 4k its not slow but my laguna II 1.8 16v with about same bhp dont have brilliant lowdown revvs under 2k not as good as the zafira but once there it will pull away from it up to 80-90mph
 
I thought diesels had longer gear ratios than petrols ive driven my nan vauxhall zafira 1.9 cdti 120bhp and it goes quite well you really feel the turbo boost in 1st 2nd and 3rd but only revvs to about 4k its not slow but my laguna II 1.8 16v with about same bhp dont have brilliant lowdown revvs under 2k not as good as the zafira but once there it will pull away from it up to 80-90mph

It's all about torque at the driven wheels when it comes to acceleration. Gears just trade revs/torque at the flywheel for torque/revs at the roadwheels. The total power transmitted in the whole system is the same either side of the box.

A diesel has higher gear ratios but the payback is that they don't have the revability of a petrol engine. But diesels do generally pull much harder from much lower revs.

You shouldn't really be aware of boost on/off with the 120 CDTi; it should be pretty linear across the rev range if the engine is running properly and is well maintained. Not my favourite 4 cylinder diesel units either, they can be quite rough, as can VAG's 4 cylinder PD units.
 
I thought diesels had longer gear ratios than petrols ive driven my nan vauxhall zafira 1.9 cdti 120bhp and it goes quite well you really feel the turbo boost in 1st 2nd and 3rd but only revvs to about 4k its not slow but my laguna II 1.8 16v with about same bhp dont have brilliant lowdown revvs under 2k not as good as the zafira but once there it will pull away from it up to 80-90mph

That's like comparing a dog poo with a cat poo though :lol:
 
That's like comparing a dog poo with a cat poo though :lol:

The analogy presented here by MA might be a little harsh; in practice neither car has any pretentions of performance.

Yet neither is inadequate for daily usage - they'll both do it well, even if they each do so in an uninspiring fashion.

They'll both get on with the job at hand in an unoffensive way.
 
It could just be mostly the torque that pulls it well working with the turbo. Remapped diesels can be impressive when pushing over 180 bhp with big torque.
 

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