Diesel just doesn't win me over....

[ORD]

I agree with the guy who said that people get annoyed because diesels are impossible to avoid. It took me months to find a decent petrol 3 series touring. Thousands of horrid 320ds!

[Welshbeef]

ORD said:

I agree with the guy who said that people get annoyed because diesels are impossible to avoid. It took me months to find a decent petrol 3 series touring. Thousands of horrid 320ds!

So few punters buy news cars personally most are
Hire cars
Rentals
Lease contract hire
Company cars
X dealer demos

Then the private buyer.

Company cars... I cannot recall seeing a petrol on the car list is say for at least ten years, hire cars always going to be diesel really.


So yep it's hard to find them as frankly hardly any were sold new.
Frustrating for sure if you are looking for a nice petrol. But ongoing there is no 330i I6 it's an I4 328i nice and faster more economic but sadly even if you want one you cannot buy one.

[luckystrike]

stavers said:

Not to say that petrol cars are free from this. Most newer petrol cars have DMFs which are just as prone to failure as the diesels. I've been looking at Alfa 159 V6s, Saab 2.8 V6T and Vauxhall 2.8 V6T and having seen they all have DMFs I am greatly put off them!

DMFs are put under less strain in petrol cars than diesels.

Vibration and excess loading is what kills DMFs, so both the combustion method itself and typical driving style for diesel cars puts them in a risky place compared to the equivalent petrol.

Diesel combustion results in much higher torque spikes than petrol, so while placed under any significant load (such as pulling away from stationary) the peak torque delivered on each combustion will be transmitting higher forces into the DMF than the equivalent petrol. This is exacerbated by the ease with which diesels can just be chugged off the line - whereas a petrol needs a few extra revs to keep it smooth/stop it stalling when pulling away, plenty of diesels can just be chugged about barely above idle, which is a high load case for the DMF.

It's not a hard and fast rule, and of course DMFs are designed for the engine application they're going into, but by and large petrol DMFs have an easier time of it.

[stavers]

luckystrike said:

stavers said:

Not to say that petrol cars are free from this. Most newer petrol cars have DMFs which are just as prone to failure as the diesels. I've been looking at Alfa 159 V6s, Saab 2.8 V6T and Vauxhall 2.8 V6T and having seen they all have DMFs I am greatly put off them!

DMFs are put under less strain in petrol cars than diesels.

Vibration and excess loading is what kills DMFs, so both the combustion method itself and typical driving style for diesel cars puts them in a risky place compared to the equivalent petrol.

Diesel combustion results in much higher torque spikes than petrol, so while placed under any significant load (such as pulling away from stationary) the peak torque delivered on each combustion will be transmitting higher forces into the DMF than the equivalent petrol. This is exacerbated by the ease with which diesels can just be chugged off the line - whereas a petrol needs a few extra revs to keep it smooth/stop it stalling when pulling away, plenty of diesels can just be chugged about barely above idle, which is a high load case for the DMF.

It's not a hard and fast rule, and of course DMFs are designed for the engine application they're going into, but by and large petrol DMFs have an easier time of it.

Agree with everything you've said.
I'm only reporting what I have seen on forums about the bigger engined petrol cars with DMFs as I (currently) don't own one but I am still worried given that people on the forums still seem to complain about clutch/DMF failures at similar miles to diesels.

[Welshbeef]

luckystrike said:

DMFs are put under less strain in petrol cars than diesels.

Vibration and excess loading is what kills DMFs, so both the combustion method itself and typical driving style for diesel cars puts them in a risky place compared to the equivalent petrol.

Diesel combustion results in much higher torque spikes than petrol, so while placed under any significant load (such as pulling away from stationary) the peak torque delivered on each combustion will be transmitting higher forces into the DMF than the equivalent petrol. This is exacerbated by the ease with which diesels can just be chugged off the line - whereas a petrol needs a few extra revs to keep it smooth/stop it stalling when pulling away, plenty of diesels can just be chugged about barely above idle, which is a high load case for the DMF.

It's not a hard and fast rule, and of course DMFs are designed for the engine application they're going into, but by and large petrol DMFs have an easier time of it.

Unless there is factual evidence stating what the failure rate per 1,000 cars is then it's all hear say - as we all know it's only when things go wrong do people make noise. What about the millions of diesels which are working perfectly fine.


The issues of HPFP (injector failure) on the 330i (petrol) were huge it's a very unreliable engine

[luckystrike]

Welshbeef said:

Unless there is factual evidence stating what the failure rate per 1,000 cars is then it's all hear say - as we all know it's only when things go wrong do people make noise. What about the millions of diesels which are working perfectly fine.


The issues of HPFP (injector failure) on the 330i (petrol) were huge it's a very unreliable engine

I don't see how that's really relevant to my post - nowhere did I say 'all diesel DMFs die'. In fact, I specifically wrote a caveat concerning that point at the end of my post.

I wasn't talking about specific failure rates, as oddly enough I don't have lots of info regarding it readily to hand. What I said was the load cases experienced by diesel DMFs are higher due to the nature of diesel combustion, of which there is plenty of factual evidence. It's not a great leap of reasoning to suggest that parts put under greater loads are potentially more prone to failure.

Iphone screens crack all the time when you drop them too - equally as relevant as injectors

[Devil2575]

ORD said:

I agree with the guy who said that people get annoyed because diesels are impossible to avoid. It took me months to find a decent petrol 3 series touring. Thousands of horrid 320ds!

But what petrol 3 series were you looking for? 320d sales aren't replacing 330i sales, they are replacing 320i sales.

A few years back it was difficult to buy a decent 328i because they were all 316s and 318s.

[Welshbeef]

luckystrike said:

I don't see how that's really relevant to my post - nowhere did I say 'all diesel DMFs die'. In fact, I specifically wrote a caveat concerning that point at the end of my post.

I wasn't talking about specific failure rates, as oddly enough I don't have lots of info regarding it readily to hand. What I said was the load cases experienced by diesel DMFs are higher due to the nature of diesel combustion, of which there is plenty of factual evidence. It's not a great leap of reasoning to suggest that parts put under greater loads are potentially more prone to failure.

Iphone screens crack all the time when you drop them too - equally as relevant as injectors

So your point is cars all cars can break. Petrol derv gas.

Unless we have failure rates then really it's a moot point.

[luckystrike]

Welshbeef said:

So your point is cars all cars can break. Petrol derv gas.

Unless we have failure rates then really it's a moot point.

No, it wasn't. Read it again.

As an extreme example to highlight the point, I've not seen reliability data concerning engine block integrity. However, given their load cases, I'd wager this:

https://youtu.be/kCsSVLZ6wCI?t=30s

is likely to happen a lot more frequently in tractor pull competitions than when driving a 1 litre micra to the shops and back.

All cars can break, but certain things can make certian failures more or less likely. In the case of DMFs, diesel load cases make it more likely compared to petrols than less.

[Welshbeef]

luckystrike said:

No, it wasn't. Read it again.

As an extreme example to highlight the point, I've not seen reliability data concerning engine block integrity. However, given their load cases, I'd wager this:

https://youtu.be/kCsSVLZ6wCI?t=30s

is likely to happen a lot more frequently in tractor pull competitions than when driving a 1 litre micra to the shops and back.

All cars can break, but certain things can make certian failures more or less likely. In the case of DMFs, diesel load cases make it more likely compared to petrols than less.

We must have failure rates per 1,000 that is all.
People can spout all sorts online but facts are indisputable

[Mr Tidy]

Welshbeef said:

The issues of HPFP (injector failure) on the 330i (petrol) were huge it's a very unreliable engine

But only on the N53 engine as it has direct injection.
The early 330is have the N52 which does not have HPFP or injector issues, and is a wonderful engine (have one in my Z4C) even if it is a band higher for road tax!

[AClownsPocket]

daemon said:

If you've jumped out of a mk7 GTI and into some Vauxhall not-so-state-of-the-art loan car, its not really a surprise you're not impressed.

Is it an Astra or Insignia?

Insignia. Might be better in an Astra. I've owned diesels in the past, a 530D, Mondeo ST TDci and found them perfectly acceptable modes of transport. This just isn't.

[ORD]

Devil2575 said:

But what petrol 3 series were you looking for? 320d sales aren't replacing 330i sales, they are replacing 320i sales.

A few years back it was difficult to buy a decent 328i because they were all 316s and 318s.

Anything from the 320i upwards. Pretty much nothing.

The 320d largely replaced all petrol 3 series, not just the 320!

[Welshbeef]

ORD said:

Anything from the 320i upwards. Pretty much nothing.

The 320d largely replaced all petrol 3 series, not just the 320!

Actually there are loads of 335is far more than 330is so look higher up or go M3 instead.

[Fastdruid]

Welshbeef said:

luckystrike said:

No, it wasn't. Read it again.

As an extreme example to highlight the point, I've not seen reliability data concerning engine block integrity. However, given their load cases, I'd wager this:

https://youtu.be/kCsSVLZ6wCI?t=30s

is likely to happen a lot more frequently in tractor pull competitions than when driving a 1 litre micra to the shops and back.

All cars can break, but certain things can make certian failures more or less likely. In the case of DMFs, diesel load cases make it more likely compared to petrols than less.

We must have failure rates per 1,000 that is all.
People can spout all sorts online but facts are indisputable

Not specific to DMF and a few years out of date but http://www.honestjohn.co.uk/news/buying-and-sellin...

[ORD]

Welshbeef said:

Actually there are loads of 335is far more than 330is so look higher up or go M3 instead.

Couldn't justify the 335 to my wife (it being her car). She thought £10k extra for performance she didn't want might be OTT

330i was the goal but they are incredibly rare.

M3 estate? Meh.

[Welshbeef]

ORD said:

Welshbeef said:

Actually there are loads of 335is far more than 330is so look higher up or go M3 instead.

Couldn't justify the 335 to my wife (it being her car). She thought £10k extra for performance she didn't want might be OTT

330i was the goal but they are incredibly rare.

M3 estate? Meh.

£10k more? They were only £3k more new will be a smaller gap now in their used values.

[ORD]

Welshbeef said:

£10k more? They were only £3k more new will be a smaller gap now in their used values.

The only one available when we were looking. It was very low mileage! I am pretty sure we ruled out autos as well, although I can't remember exactly. In any case, it came down to having to pay £10k more (or nearly that much), which seemed OTT.

[Fastdruid]

ORD said:

Welshbeef said:

Actually there are loads of 335is far more than 330is so look higher up or go M3 instead.

Couldn't justify the 335 to my wife (it being her car). She thought £10k extra for performance she didn't want might be OTT

330i was the goal but they are incredibly rare.

M3 estate? Meh.

Yeah, same with trying to find a 2005+ manual 525i or 530i Touring so I got an (equally rare) Mondeo 2.5T Estate instead..... Quicker than the 525i at least and significantly cheaper and better spec'd. Still slightly tempted to upgrade to a 530i if I ever find one although will probably run this for a few more years.

[Welshbeef]

ORD said:

Welshbeef said:

£10k more? They were only £3k more new will be a smaller gap now in their used values.

The only one available when we were looking. It was very low mileage! I am pretty sure we ruled out autos as well, although I can't remember exactly. In any case, it came down to having to pay £10k more (or nearly that much), which seemed OTT.

What was the budget?

Well worth waiting for the right one to come along and not being afraid of higher miles. Plus stick shift was £3k less new over and auto so dead cheap used us those who like to modify these cannot wth the stick shift as the clutch and torque rating of the box is vastly less than the auto.