Are diesels very different from petrols

[billyo]

Ive been thinking of getting a Diesel turbo but all I have ever driven is a petrol. What are the differences from a petrol from the drivers point of view. Other than changing gear more often do you have to be more gentle or brutal with the gas pedal?

[waynne]

I'd say they are more forgiving. It's easy to kangaroo in a petrol but not as easy in a Diesel.

[HDi fun]

The presence of turbo lag, however brief, does have a damping effect in general. You don't really need to change gear more often, you just change at different points in the rev range. A good diesel will produce usable power from 1500rpm but the party's over by 4000rpm.

As for pedal response - this depends entirely on the individual car, exactly the case as with petrol cars. People tend to lump diesels into one category. There's no way you can liken a modern diesel car to the way a 1985 Cavalier 1.6D was.

[turbonutter69]

Originally Posted by HDi fun

The presence of turbo lag, however brief, does have a damping effect in general. You don't really need to change gear more often, you just change at different points in the rev range. A good diesel will produce usable power from 1500rpm but the party's over by 4000rpm.

As for pedal response - this depends entirely on the individual car, exactly the case as with petrol cars. People tend to lump diesels into one category. There's no way you can liken a modern diesel car to the way a 1985 Cavalier 1.6D was.

I had an L reg Mondeo Td. It was a proper slug in first and second, But get in third and wind the boost up an it really shifted from third and above. I got 100mph or so on the back straight when I took it round cadwell park.. Had nothing in 1st or 2nd but above that it was great.

[pgarner]

i got a diesel last week as a courtasy car, bit different to drive in the sense of changing earlier but that was really it. constantly foun myself wantingto drop it as i was sitting under 2k rpm.

[HDi fun]

An L plated Mondeo TD is nothing like the current crop of diesels. Contrast its 80-90bhp with the 190bhp and 320 lbft plus (that's the really impressive part - go and look up the torque figure for an XK8 and you get an idea of the shove on offer) mine delivers. Agreed it's remapped but it's not underpowered in stock tune either.

Acceleration in 3rd and 4th is phenomenal.

[turbonutter69]

Oh yes I agree totally. I was just giving an example thats all. Diesels have really come along way haven't they in the last few years.

[HDi fun]

They have. In some ways we've lost the original design goal, which was simplicity. No electrics whatsoever - mechanical injection etc. etc all featured.

But, to drive - they're stunning. My Primera was lively by anyone's standards but it wouldn't get near the 406 I have now. (Nor will most 3.0 litre petrol V6 cars either).

[turbonutter69]

Originally Posted by HDi fun

They have. In some ways we've lost the original design goal, which was simplicity. No electrics whatsoever - mechanical injection etc. etc all featured.

But, to drive - they're stunning. My Primera was lively by anyone's standards but it wouldn't get near the 406 I have now. (Nor will most 3.0 litre petrol V6 cars either).

I'd have a go lol But I understand what your saying mate. I just like the sound of petrol so I think it'll be a few years till i'm converted to diesel...

[HDi fun]

There's a way to go yet with the sound they make outside the car. Much quieter than they used to be but a decent V6 petrol is almost inaudible outside.

In the car though, things have really improved. You really can't tell that it's a 4 cylinder engine, let alone a diesel one.

I'll also add that I was a diesel HATER for years.

[turbonutter69]

Originally Posted by HDi fun

There's a way to go yet with the sound they make outside the car. Much quieter than they used to be but a decent V6 petrol is almost inaudible outside.

In the car though, things have really improved. You really can't tell that it's a 4 cylinder engine, let alone a diesel one.

I'll also add that I was a diesel HATER for years.

Oh I'm not a hater I do quite like some diesel models. But I do like a long rev range. But generally if it's a 2 litre or above diesel i'll prob like it. I loved my mondeo when the turbo spooled up,,,when...lol

[BAD63R]

Diesels are definatly gettin better these day. I've heard a couple of V6 diesels that actually sound quite meaty. Plus if you think of the Audi diesel that won the Le Mans 24, they have very kindly given that engine to us public in the Audi R8, and to be fair you couldn't even tell from the sound of it that it's diesel. Sounds awsome.

[HDi fun]

A V6 or V8 diesel can sound very nice indeed, especially when both turbochargers are running at full pressure. It's not dissimilar to a jet aircraft under full acceleration at take off.

[waynne]

I thought we had dispelled the myth that a diesel won Le Mans, just like the faked moon landing.

[HDi fun]

Try a 1985 Sierra 2.3D and find out just how bad a diesel engine can be. The VW Audi mid 1990's 2.5 5 cylinder was also a dog even in 140bhp tune.

VW and Peugeot Citroen led the way to today's smooth, quiet, and powerful diesel engines.

It's the massive torque figures that really make 'em fun, especially with a performance remap. Consider this, the Jaguar XK8 has 320lbft torque at 4000rpm, and that's a 4.0 litre V8. My car delivers this much at 2300rpm. For sure, it won't rev round to 6500rpm so the top end is not there but in everyday driving you have that same driving 'feel' urgent feel of immediate and strong acceleration.

And, yes, for clarity, I have driven an XK8.

[turbonutter69]

Originally Posted by HDi fun

Try a 1985 Sierra 2.3D and find out just how bad a diesel engine can be. The VW Audi mid 1990's 2.5 5 cylinder was also a dog even in 140bhp tune.

VW and Peugeot Citroen led the way to today's smooth, quiet, and powerful diesel engines.

It's the massive torque figures that really make 'em fun, especially with a performance remap. Consider this, the Jaguar XK8 has 320lbft torque at 4000rpm, and that's a 4.0 litre V8. My car delivers this much at 2300rpm. For sure, it won't rev round to 6500rpm so the top end is not there but in everyday driving you have that same driving 'feel' urgent feel of immediate and strong acceleration.

And, yes, for clarity, I have driven an XK8.

Totally agree with you there mate diesels have come a very long way. An I do like a strong pull on acceleration. But you know me I like that rev range of a petrol. An throw in a turbo for added fun lol....
But yes diesels are very very good nowadays.

[HDi fun]

Diesels are a bit limited in revs. But modern ones are doing useful work from as low as 1300rpm. so it's not so bad. Mine revs to over 5300rpm before the limiter starts to intervene. This, I know, is unusually high and, to be honest there's no point in going over 4300 where peak bhp is produced.

When there's a TQ cars meet we'll have a little race if you like. I think you'll get a bit of a surprise. I used to have a primera and it was quick, without question. But I reckon the remapped 406 will flatten it.

[turbonutter69]

Originally Posted by HDi fun

Diesels are a bit limited in revs. But modern ones are doing useful work from as low as 1300rpm. so it's not so bad. Mine revs to over 5300rpm before the limiter starts to intervene. This, I know, is unusually high and, to be honest there's no point in going over 4300 where peak bhp is produced.

When there's a TQ cars meet we'll have a little race if you like. I think you'll get a bit of a surprise. I used to have a primera and it was quick, without question. But I reckon the remapped 406 will flatten it.

I'm up for that mate but I'm not saying diesels are slow. I just like a long rev range. But we should organise a meet sometime next year I think...

[HDi fun]

It's about time really. We've all been planning something for a while. I think it's the financial situation that's stopping all us organising this.

I, too, like long rev range that a good petrol engine can offer - I adored the way my Primera would go beyond the 7300 red line and limiter started to intervene at 7600!

But I did find it spineless below about 4500rpm throughout the whole time I owned it, which was from about 300 miles to 170,000 miles. And there was no way I'd have bought a diesel in 1997 as they were just not up to it, in my opinion.

The P11 is a stunning handler, I used to take ridiculous liberties with it, take bends at 85mph in the wet that I wouldn't have taken at 65 in the dry in something else.

[jarrus]

Originally Posted by HDi fun

They have. In some ways we've lost the original design goal, which was simplicity. No electrics whatsoever - mechanical injection etc. etc all featured.

But, to drive - they're stunning. My Primera was lively by anyone's standards but it wouldn't get near the 406 I have now. (Nor will most 3.0 litre petrol V6 cars either).

If you want a good simple reliable diesel then nothing beats the old pug 1.9 DT engine.....

You can get sizeable gains from a simple tune up, and they already have a redlline of 5000 rpm my car will pull up to that in every gear except 5th (exhaust is very restrictive)
love it....

http://jacmech.co.uk/tuning.html

http://jacmech.co.uk/projects.html

there something in there about the HDi engines as well....

[turbonutter69]

Originally Posted by HDi fun

It's about time really. We've all been planning something for a while. I think it's the financial situation that's stopping all us organising this.

I, too, like long rev range that a good petrol engine can offer - I adored the way my Primera would go beyond the 7300 red line and limiter started to intervene at 7600!

But I did find it spineless below about 4500rpm throughout the whole time I owned it, which was from about 300 miles to 170,000 miles. And there was no way I'd have bought a diesel in 1997 as they were just not up to it, in my opinion.

The P11 is a stunning handler, I used to take ridiculous liberties with it, take bends at 85mph in the wet that I wouldn't have taken at 65 in the dry in something else.

Mine is really strong on the top end of the rev range above 4000 revs and it flies.

[HDi fun]

"Mine is really strong on the top end of the rev range above 4000 revs and it flies."

Yes, I know that, too. I had one for eight years. I also found it sppineless at lower reves.

And I still guarantee that the 406 I have now will flatten it effortlessly.

[HDi fun]

Originally Posted by jarrus464

If you want a good simple reliable diesel then nothing beats the old pug 1.9 DT engine.....

You can get sizeable gains from a simple tune up, and they already have a redlline of 5000 rpm my car will pull up to that in every gear except 5th (exhaust is very restrictive)
love it....

http://jacmech.co.uk/tuning.html

http://jacmech.co.uk/projects.html

there something in there about the HDi engines as well....

I'll stick with my DW12TED4 thanks.

[turbonutter69]

Originally Posted by HDi fun

"Mine is really strong on the top end of the rev range above 4000 revs and it flies."

Yes, I know that, too. I had one for eight years. I also found it sppineless at lower reves.

And I still guarantee that the 406 I have now will flatten it effortlessly.

You know what I'll say to that lol......
If I pull off in the Primera and floor it straight away its great pulls strong through every gear. But if say i'm cruising in third gear at about 2500rpm and then floor it, It's like turbo lag then when the revs get to that sweet spot all hell breaks loose it's great.

[HDi fun]

30-60 - four seconds in third gear