[kinesiologykid]

Hi kinesiologykid

I think its the public, not the carmaker that is to blame.

I have been away from Oz for too long. I have long wondered if the Yanks have thought that the minimum weight for a baby car is two tons.  :cry:

Take a Look at the Hyundai sales figures for the USA in August here. http://www.hyundai-blog.com/index.php/2008/09/09/hyundai-car-sales-report-august-2008/#more-406
It looks as if even our American Cousins are beginning to get their heads around the benefits of driving human scale cars and not 'battle tanks'. Unfortunately by only dropping back to the delightful Sonata they still have some way to go. As there are not yet enough i30s built to let them in on the deal we shall just have to hope they will embrace the i30 Wagon to be called the Elantra Wagon, I think, when it is released in the USA. But then again the Yanks might look for a 3.0l V6.

The only consolation for those who already have one is the continuing good sales of the i30 here.[/color]

Interesting link, Bunyip,
So the US is slowly heading in the right direction.
The only thing that will really change people is sudden increased prices, otherwise its like the lobster getting slowly boiled, doesn't notice until its too late!

Yes, Governments have the power to make massive changes.
If only they had the balls!
Nobody needs a bigger car than i30/Focus/Corolla/Mazda 3/Honda Civic etc, (unless they have big loads to carry) and if the government set the standard for government cars at 4l/100km (diesel) or 6l/100km petrol, then the carmakers will make them!

If they need lengthy journeys on unsealed roads, then Subaru Foresters can be coverted to LPG.
Government cars mainly used in the city should be LPG Hybrid or totally electric (only a few years away).

This is a great site for future models, has some very green cars, including future LPG hybrid Elantra:
http://www.editorial.discountnewcars.co ... enDocument

[EymaTeapot]

[
Nobody needs a bigger car than i30/Focus/Corolla/Mazda 3/Honda Civic etc, (unless they have big loads to carry) and if the government set the standard for government cars at 4l/100km (diesel) or 6l/100km petrol, then the carmakers will make them!

What if you have 5 kids?

[kinesiologykid]

[
Nobody needs a bigger car than i30/Focus/Corolla/Mazda 3/Honda Civic etc, (unless they have big loads to carry) and if the government set the standard for government cars at 4l/100km (diesel) or 6l/100km petrol, then the carmakers will make them!

What if you have 5 kids?

Okay Eyma Teapot, you got me!
But I guess it wouldn't be a high % of governement employees with five kids?

[donc]

Different persepectives always give rise to interesting discussion! - From my perspective; I really can't understand why anyone needs a car at all if they live in one of our large city's with public transport so cheaply available. I wonder why city folk don't just hire a car for weekend trips (actually I know a lot do use public transport and hire cars when required, but seemingly a lot more seem to feel they need both a cheap public transport system and a private car at their personal disposal 24x7 - This is a huge waste of energy).

If we had trains and buses available in rural districts we could also do without expensive cars... but we don't so it's not much use dreaming

Another consideration is maybe to acknowledge how the real environmental cost of running a car doesn't begin and end at the bowser. A lot more raw materials are used to build a car that to run it for 100,000 km, and with anecdotal evidence supporting that cars last longer if the engine isn't so small as to be working overtime, it can actually work out cheaper from an environmental perspective if the power to weight ratio supports vehicle longevity.  

How many K's would you expect to get out of a 1.6 litre petrol? - I'll be very disapointed if the 2.0 ltr doesn't better 350,000 km over the life of the engine.

[kinesiologykid]

Different persepectives always give rise to interesting discussion! - From my perspective; I really can't understand why anyone needs a car at all if they live in one of our large city's with public transport so cheaply available. I wonder why city folk don't just hire a car for weekend trips (actually I know a lot do use public transport and hire cars when required, but seemingly a lot more seem to feel they need both a cheap public transport system and a private car at their personal disposal 24x7 - This is a huge waste of energy).

If we had trains and buses available in rural districts we could also do without expensive cars... but we don't so it's not much use dreaming

Another consideration is maybe to acknowledge how the real environmental cost of running a car doesn't begin and end at the bowser. A lot more raw materials are used to build a car that to run it for 100,000 km, and with anecdotal evidence supporting that cars last longer if the engine isn't so small as to be working overtime, it can actually work out cheaper from an environmental perspective if the power to weight ratio supports vehicle longevity.  

How many K's would you expect to get out of a 1.6 litre petrol? - I'll be very disapointed if the 2.0 ltr doesn't better 350,000 km over the life of the engine.

Hi Donc,
If I didn't need to travel for work (about 230kms once a week, to a place with virtually no public transport, and not knowing my finish times) I maybe could do without a car.
Launceston is such a small city, I can walk to almost anywhere in 15-20 minutes.

I think if you get 250,000 out of a 2.0 litre petrol you are doing okay.
I would expect the 2.0 litre to maybe get 50,000 more than a 1.6 petrol.
And the 1.6 diesel to get 350,000.
Just guesses, based on what I have read.
The average car probably 'dies' of old age before 250,000.

Be good to have a government funded website that factored everything in, including the freight from Korea, and where the steel comes from to build it - total environment cost. It is so difficult for the average person to work out.
It could have a graph that showed which model was best based on average km per year, and whether country or city driving.

So it could be sorted by:

Safest small car

Most economical city car
Safest city car

Most economical highway car
Safest highway car

Most economical country roads car
Safest country roads car

For instance the Mercedes A-Class tops the small car safety (howsafeisyourcar.com.au)
BUT its not meant to be driven on anything but bitumen.
So it may be safest highway car and city car, but would probably be the least economical country car based on all the (expensive) repairs it would need.
A staggering 37% would not buty another mercedes! http://www.carsurvey.org/
Interestingly on the same site only 10% of Hyundai Getz owners would not buy another Hyundai!!!!!
Unfortunately its too small a sample for the i30 - hint hint.

The Fiat 500 and Punto are great safe city cars, but considerably smaller than the i30 for highway driving.

The i30 beat a Porsche 911 in a rally and also trounced a Toyota Prius in an economy run.
But the Prius is best in the city, as it can use the electric engine.

Most of the members on this site would also have different needs.
Some need a car that can do 200km/hr.
Some need economy.
Some desire safety.
Some live in the city, others the country.
Some like zooming round winding bends.

Isn't it amazing the i30 meets all of our needs!

[donc]

Hi Donc,
If I didn't need to travel for work (about 230kms once a week, to a place with virtually no public transport, and not knowing my finish times) I maybe could do without a car.
Launceston is such a small city, I can walk to almost anywhere in 15-20 minutes.

Hi kinesiologykid - not so long ago I couldn't even walk to the end of my driveway in less than 20 mins - Nowadays we live in town so it's a little easier. Still there are times when I would love to have public transport available. IMO a lot of city folk don't realise how lucky they are to get so much public money spent on their transport needs - at least that's how it seems judging by all the complaining I see in the media when a train is 5 minutes late.

I think if you get 250,000 out of a 2.0 litre petrol you are doing okay. I would expect the 2.0 litre to maybe get 50,000 more than a 1.6 petrol. And the 1.6 diesel to get 350,000. Just guesses, based on what I have read. The average car probably 'dies' of old age before 250,000.

Mate, to be honest these are assumptions I have some difficulty with. You're suggesting an approx 30% increase in engine life from a 1.6 ltr diesel over a 2.0 litre petrol engine. I had similar discussion with my dealer when we first discussed the diesel -v- ULP option. Like most car salesman I've met when talking diesels, his immediate sales pitch was to cite the '70's - '80's truism of a diesel being more reliable and longer lasting (he said it so quickly I'm sure he had never really thought about it before)... and I think he was a little suprised when I called him on it. In the end he did end up agreeing with me.

Diesel engines of decades past did last longer on average than petrol engines and were (as a rule) more reliable. This was because most didn't rev over 2,000 rpm, were naturally aspirated and had a bottom-end 3x times the weight of the petrol counterpart. In short, the diesel generated little high-end power, reved very slowly and basically didn't work particularly hard. This is also why the few diesel cars of this era were so unsuccessful and unpopular - they lasted well, peformed terribly.  

Enter the turbocharger, higher reving diesels (i30 1.6 Crdi 85kw @ 4000 rpm), light-weight construction to try and 'trim the fat' from a traditionally heavy diesel bottom end and a diesel with peformance figures comparable to a petrol engine... some great benefits, but a counterpart of there isn't even anecdotal evidence (or logic) to suggest the diesel should have any greater life expectancy than the petrol engine. It's more likely to be the reverse considering the lengths taken to reduce the bottom end weight. Time will tell, but I would certainly take any claims of improved longevity with a grain of salt until such time as proper statistics become avaialble.

The i30 beat a Porsche 911 in a rally and also trounced a Toyota Prius in an economy run.
But the Prius is best in the city, as it can use the electric engine.

Interesting! - I haven't heard about this - How old was the Porsche? I'm guessing we are talking time trials and all things equal? Would like to hear more...

Isn't it amazing the i30 meets all of our needs!

Kinda - a  great little car - I wouldn't suggest it meets all needs, but it is a good package.

[kinesiologykid]

Hi Donc,
If I didn't need to travel for work (about 230kms once a week, to a place with virtually no public transport, and not knowing my finish times) I maybe could do without a car.
Launceston is such a small city, I can walk to almost anywhere in 15-20 minutes.

Hi kinesiologykid - not so long ago I couldn't even walk to the end of my driveway in less than 20 mins - Nowadays we live in town so it's a little easier. Still there are times when I would love to have public transport available. IMO a lot of city folk don't realise how lucky they are to get so much public money spent on their transport needs - at least that's how it seems judging by all the complaining I see in the media when a train is 5 minutes late.

I think if you get 250,000 out of a 2.0 litre petrol you are doing okay. I would expect the 2.0 litre to maybe get 50,000 more than a 1.6 petrol. And the 1.6 diesel to get 350,000. Just guesses, based on what I have read. The average car probably 'dies' of old age before 250,000.

Mate, to be honest these are assumptions I have some difficulty with. You're suggesting an approx 30% increase in engine life from a 1.6 ltr diesel over a 2.0 litre petrol engine. I had similar discussion with my dealer when we first discussed the diesel -v- ULP option. Like most car salesman I've met when talking diesels, his immediate sales pitch was to cite the '70's - '80's truism of a diesel being more reliable and longer lasting (he said it so quickly I'm sure he had never really thought about it before)... and I think he was a little suprised when I called him on it. In the end he did end up agreeing with me.

Diesel engines of decades past did last longer on average than petrol engines and were (as a rule) more reliable. This was because most didn't rev over 2,000 rpm, were naturally aspirated and had a bottom-end 3x times the weight of the petrol counterpart. In short, the diesel generated little high-end power, reved very slowly and basically didn't work particularly hard. This is also why the few diesel cars of this era were so unsuccessful and unpopular - they lasted well, peformed terribly.  

Enter the turbocharger, higher reving diesels (i30 1.6 Crdi 85kw @ 4000 rpm), light-weight construction to try and 'trim the fat' from a traditionally heavy diesel bottom end and a diesel with peformance figures comparable to a petrol engine... some great benefits, but a counterpart of there isn't even anecdotal evidence (or logic) to suggest the diesel should have any greater life expectancy than the petrol engine. It's more likely to be the reverse considering the lengths taken to reduce the bottom end weight. Time will tell, but I would certainly take any claims of improved longevity with a grain of salt until such time as proper statistics become avaialble.

The i30 beat a Porsche 911 in a rally and also trounced a Toyota Prius in an economy run.
But the Prius is best in the city, as it can use the electric engine.

Interesting! - I haven't heard about this - How old was the Porsche? I'm guessing we are talking time trials and all things equal? Would like to hear more...

Isn't it amazing the i30 meets all of our needs!

Kinda - a  great little car - I wouldn't suggest it meets all needs, but it is a good package.

Hi Donc,
As I said it was a guess, what you say about the newer diesel engines being lighter, therefore not as strong is new to me, so thanks, I am learning so much lately! I guess only time will tell.
I have only done 500km up to now, but find it hard to get to 4000 rev! I will most likely be running mine at less than 2,500 rev, over 90% of the time, so may last a bit longer than some of the members who drive redline!

There is a whole section on the Targa Rally in this site, viewtopic.php?f=7&t=796

Also on other sites, e.g. http://autodeadline.com.au/?page=ViewRe ... 8090875847

I meant meets the needs of the members on this site, even though we go from old codgers just wanting good economy to would be Corolla buyers because they can get ESP, to would be Lancer buyers, because it handles well.

[Lakes]

i just got home from a trip down the south coast. and the little CRDi was never overtaken up or down the princess Hwy. i followed a late model SS comodore Ute down we over took everything but drove safe, he could not get away from me even up hills or around tight bends and i was not realy pushing it.
very happy as it was raining heavy on way home and the i30 SX still handled that well also had traffic stop fast in the rain @ 110kph  i used the ABS and the tyres griped perfect no skid.
and on saturday night south of Narooma we had a Wallaby come out of the sticks almost hit it, so was lucky.
i'm very happy with my choice as the SX CRDi was cheap and suits me fine.
Cheers

[donc]

There is a whole section on the Targa Rally in this site,

Thanks for the link - Fascinating thread and a good read! - Would love to hear/read more on the other vehicles competing in the same class as the i30. I can see Jimmy Richards finished 2nd overal in a 911 behind a hot looking Skyline GTR, and an old '74 model 911 won the vintage class. What model/vintage was the Porsche beaten by the i30?

PS - some old codgers look for more than just economy in a car... some like a car with a bit of spirit as well!

[LuciferDarklord]

Hi Donc.  The Porsche is a 1984 911 Targa according to the entry list. Below is a pic.  Not the fastest Porsche by any stretch of the imagination, but none the less its a sports car, not an econo diesel hatchback!  I think a lot comes down to Razy's driving too, he was fairly up it at all times.  I guess in the context of it, a lot of the cars aren't readily replaceable, but Razy had the fortune of being able to drive close to the limit the whole time.

[donc]

The average car probably 'dies' of old age before 250,000.

Hi kinesiology (I'll drop the 'kid' part, but an interesting handle - practitioner or patient?)

Unfortunately I think you are correct. Another sad reflection on our 'dosposable' society. Cars don;t wear out after 250,000 km, people let them wear out through lack of proper maintenance. This lack of longevity is probably the single most costly environmental aspect of the motor car.

I spent today degreasing the engine and tuning my daughters 1992 model 2.0 ltr DOHC Mazda 626 Hatch (I was going to fit an anti-glare strip to the i30 but time got away from me!). The 626 is a classic, and one of my old work cars that I gave to her while she is learning to drive. The car has 327,000 km on the clock. The paintwork is starting to look a little sad but the car runs fantastically well. One of these days I'll give it a new coat of paint. Being a 626 I expect to get better than 400,000 km out of it.

Theoretically a car should last for ever if it's properly built and maintained.

[donc]

Hi Donc.  The Porsche is a 1984 911 Targa according to the entry list.

Awesome - Thanks lucifer! - I also note this class was speed limited (Challenge Modern), and some of the faster cars were penalised for going too quickly... It's always going to be hard to drive a fast car at less than it's capabilities during a race event, plus I don't know if the Porsche was one of these or not... nonetheless a great result for the i30!

[kinesiologykid]

The average car probably 'dies' of old age before 250,000.

Hi kinesiology (I'll drop the 'kid' part, but an interesting handle - practitioner or patient?)

Unfortunately I think you are correct. Another sad reflection on our 'dosposable' society. Cars don;t wear out after 250,000 km, people let them wear out through lack of proper maintenance. This lack of longevity is probably the single most costly environmental aspect of the motor car.

I spent today degreasing the engine and tuning my daughters 1992 model 2.0 ltr DOHC Mazda 626 Hatch (I was going to fit an anti-glare strip to the i30 but time got away from me!). The 626 is a classic, and one of my old work cars that I gave to her while she is learning to drive. The car has 327,000 km on the clock. The paintwork is starting to look a little sad but the car runs fantastically well. One of these days I'll give it a new coat of paint. Being a 626 I expect to get better than 400,000 km out of it.

Theoretically a car should last for ever if it's properly built and maintained.

Hi Donc,
I would like to think people will take more care of the newer breed of cars with ESP and lots of airbags. Thats the main thing that stopped me buying an old car!
I have owned two Mazdas, one a 1300 that we drove from Melbourne to Daintree, four up totally full of luggage, I hardly slept because when the wife was driving and I dozed off, she was doing 120km/hr!
The other car was a 929, really nice car.
I tried to find info about the newer diesels, but not much luck.
Checking a UK website there are plenty with over 200,000 miles on the clock, best was a Citroen C3 1.4, 704,645 MILES !!!!

But then I found a petrol Hyundai 2.0 coupe, 760,000 MILES !!!

Only time will tell!
Maybe some countries may have them as taxis, then we will soon find out!

[LuciferDarklord]

Theoretically a car should last for ever if it's properly built and maintained.

A few months ago I was talking to a taxi driver, he had the same Falcon Taxi for 8 years, it was one week out from retirement.  The poor old girl had done 1.44 million km's.  It was the second engine, third transmission.  The first engine died around the one million mark, the second engine will be ripped out and kept for another cab!  It was an AU Falcon I think.  Definitely a Falcon I just cant remember the exact model.  My 1991 Nissan Navara has done well over 300,000kms - doesnt use any oil, make any silly noises - just needs a new steering box and exhaust.

As for the turbo decreasing engine life, I think that if the oil is looked after, it will only marginally increase the wear on big ends and main bearings.  If you look at the pressure curve of the engine for NA vs Turbo, the pressure increase in the turbo engines comes a fair bit after TDC.  Its really hard to explain, but I read a book about this a few years ago that had the MEP (mean effective pressure) of the cylinder vs crank angle, and all the increase in torque comes around 20 degrees ATDC, when the effective length of the crank is becoming optimum.  Ah - i found the book i was thinking of.  See below for a graphic of what I'm talking about.  I think the main part that a turbo plays in engine wear is damage to the oil from temperature.

Also, the diesel i30 still weighs a fair bit more than the petrol (36kg).  I think the block is cast iron in the diesel and aluminium alloy in the petrol.  Most modern engines use a main bearing cradle which stops the flex of the webbings for the mains and keeps everything nice and parallel. I'd reckon that the diesel 'knock' would be putting a large shock on the bearings but this isnt the case.  I'm sure there is something else in the picture that makes diesel last longer than petrol - like big end journals being larger in a diesel because it doesnt rev as high?  I dont know really....

[LuciferDarklord]

i'll put the whole section up, its an interesting read.  Bear in mind its referring to a petrol engine and 2atm of boost (nearly 30psi)  Its a fairly old book I was reading when I was doing turbo conversions on diesels in the mid 90's.  My trade is in the old school mechanical injection and governor systems on diesels (Bosch trained) - unfortunately the common rail stuff was all fairly new when I finished and changed careers.

[kinesiologykid]

Theoretically a car should last for ever if it's properly built and maintained.

A few months ago I was talking to a taxi driver, he had the same Falcon Taxi for 8 years, it was one week out from retirement.  The poor old girl had done 1.44 million km's.  It was the second engine, third transmission.  The first engine died around the one million mark, the second engine will be ripped out and kept for another cab!  It was an AU Falcon I think.  Definitely a Falcon I just cant remember the exact model.  My 1991 Nissan Navara has done well over 300,000kms - doesnt use any oil, make any silly noises - just needs a new steering box and exhaust.

Hi Lucifer,
Interesting info. Was the taxi a petrol, LPG or diesel?

[eye30]

I wonder why city folk don't just hire a car for weekend trips

In London UK, but a few places elsewhere in Uk, they have a Car Club. You join the club and pick up and return as and when you need a car.

Quote from website:
"Streetcar has cars parked in a dense network of dedicated spaces across London and several other UK cities, typically within a few minutes walk of your home or work. You can use one for as little as 30 minutes or as long as 6 months................
The cost of your usage is based on how long you have the car and how far you drive but unless you a heavy car user, the annual cost of Streetcar will be dramatically less than owning a car and with lots of the hassle of car ownership removed."

So you don't own a car just "hire" when you need it.

link:

http://www.streetcar.co.uk/

[LuciferDarklord]

Hi Lucifer,
Interesting info. Was the taxi a petrol, LPG or diesel?

LPG - Ford Falcon 4.0lt inline 6

[Lakes]

Lucifer, i'm 60 years old  i've been in transport industry since i was 18. just about everyone i know does high mileage on there cars or truck's.
It's common knowledge the average Taxi in Sydney does around 600,000k and it gets every nationality and more different drivers than you can poke a stick at floging it. so with an owner driver and care they would last longer. most of reason is they are always runing , also the oils these  days are really good.
i just drive them and service them and the miles just go up fast when you use them for work. i have a few mates that have late model small displacement high mileage CRD's no problems but they know how to drive and they use good oil and have them serviced. one guy has 250.000k on the same tyres thats on the rear double wheel 2.2 CD Turbo Sprinter Van.

On the trip this past weekend even though i was driving fast i would not have gone over about 2,600 rev at the most the little 1.6 pulls good its a long stroke so piston speed would be on high side. one of the reasons i would not have the petrol is its 4 valve i found 4 valve are ok but because of the two exhast valves they need more revs to make TQ thats unless you add a turbo . that Taxi you talked about would be AU model they still used the two valve motor, i had a ute that model i did well over 250,000? and never used or needed to be topped up with oil, then i looked at a new Ute the BA used 4 valve head i drove it but did not feel as good, so tried the three valve V8 now have 205,000k on that and its still runs as good as new i have changed oil every 5,000k on that from new. i'll keep it owes me nothing now.tyres on it last me 110,000k that the four of them, the Kumho i have on the sx i rotated @ 6,000k and i keep 40psi in them they look like they will last too.
also i don't care what anyone says i'll do 15,000k on mineral based Turbo Diesel oil before going to synthetic as i think it will get a better seal. i have been changeing the oil every 5,000k.
there was a race meet last weekend at eastern creek for old touring cars, friends told me but eastern creek is not a very good track to watch a race meet at.
cheers

[Lakes]

I wonder why city folk don't just hire a car for weekend trips

In London UK, but a few places elsewhere in Uk, they have a Car Club. You join the club and pick up and return as and when you need a car.

Quote from website:
"Streetcar has cars parked in a dense network of dedicated spaces across London and several other UK cities, typically within a few minutes walk of your home or work. You can use one for as little as 30 minutes or as long as 6 months................
The cost of your usage is based on how long you have the car and how far you drive but unless you a heavy car user, the annual cost of Streetcar will be dramatically less than owning a car and with lots of the hassle of car ownership removed."

So you don't own a car just "hire" when you need it.

link:

http://www.streetcar.co.uk/

Hey Eye they have one of those type of clubs in sydney too mostly used by inner city people. that only drive righ in the inner CBD they have reserved parking too.
but for men of your Caliber  this would be the right club to join www.supercarclub.com.au
cheers

[donc]

A few months ago I was talking to a taxi driver, he had the same Falcon Taxi for 8 years, it was one week out from retirement.  The poor old girl had done 1.44 million km's.  

Hi Lucifer,

An advantage of living in a small community; everyone knows everyone else. We only have a few taxi cabs in town but most of the older cabs have travelled over a million km's. All are LPG powered, ULP engined. Not at all ununusual for a Taxi to travel this distance as the cars are driven by professional drivers, run most of the day 24x7 and are well maintained by qualified mechanics. Most are Ford Falcoms.

Comments above seem to suggest any car can do large KM's when properly driven and maintained. My experience supports this. Conversely any car can be destroyed by a lack of proper maintenance and poor driving habits. Diesel or ULP, it doesn't matter. I have rebuilt motors with less than 100,000 km on the clock (diesel and petrol).

[donc]

one of the reasons i would not have the petrol is its 4 valve i found 4 valve are ok but because of the two exhast valves they need more revs to make TQ thats unless you add a turbo . that Taxi you talked about would be AU model they still used the two valve motor, i had a ute that model i did well over 250,000? and never used or needed to be topped up with oil, then i looked at a new Ute the BA used 4 valve head i drove it but did not feel as good, so tried the three valve V8 now have 205,000k on that and its still runs as good as new

Hiya Lakes - I don't think I've seen you post without at least once mentioning that V8 Ute - it must be your pride and joy! I've owned a few V8's over the years (Torana, 2x Commodores, 351 Falcon and a Landcruiser) and they were fun. Nowadays I prefer my cars to be smaller and nippier (or 4x4), but I still miss the sound and feel of V8 sometimes

The car I talked about that started this thread-within-a-thread (with well over 300,000 km) is a 1992 model 4 cylinder 2.0 ltr 16 valve double overhead cam... and still today from a standing start it will beat most cars on the road, and it only uses oil when I give it an oil change. The number of valves should not impact on the mileage you get out of a car.

[Shambles]

You guys just blow me away with your knowledge & experience.

I just want a beer

[donc]

I think the main part that a turbo plays in engine wear is damage to the oil from temperature.

Hi Lucifer - agreed - do you think it comes back to longevity being linked to good maintenance again? I'm not sure we can completely discount increase in engine wear from other turbo-related factors; anything that increases output must have an input cost, even if it's just base metal stressors.. although I expect this to be minimal for engines designed from scratch to be turbo'd.

 
I think the block is cast iron in the diesel and aluminium alloy in the petrol.  Most modern engines use a main bearing cradle which stops the flex of the webbings for the mains and keeps everything nice and parallel. I'd reckon that the diesel 'knock' would be putting a large shock on the bearings but this isnt the case.  I'm sure there is something else in the picture that makes diesel last longer than petrol - like big end journals being larger in a diesel because it doesnt rev as high?  I dont know really....

IMO this touches on a few base design considerations - ULP engines use a combination of electrical and mechanical forces to convert fuel to energy, diesels only use mechanical force meaning a requirement for much higher compression ratios and subsequently heavier/stronger engine componentry to prevent mechanical failure.

but... it's always a balance between power and weight meaning manufacturers, especially nowadays, use every method at their disposal to make engines as light as possible within the constraint of making them as strong as necessary. I doubt this balance really differs between modern diesel and ULP engines meaning one is as reliable as the other; one is as inherently likely to fail as the other. The days of using excessive metal and weight in big-bottomed diesel tractor engines is long gone IMO - much too expensive to build and run.  

and... there have been some spectacular failures. Daewoo (another Korean manufacturer now bankrupt), rather famously tried to improve the engine power-to-weight ratio of the Leganza model to such an extent it was known for bouncing valves off pistons when the timing belt wore (a few cars over the years with this problem!)... but worse, being light in the bottom it frequently fractured big-ends and journals meaning the whole engine had to be scrapped. A lesson learned but too late to save the company. Trouble is these sort of design problems often don't show up until cars have travelled 100,000 km or more.

Its a fairly old book I was reading when I was doing turbo conversions on diesels in the mid 90's. My trade is in the old school mechanical injection and governor systems on diesels (Bosch trained) - unfortunately the common rail stuff was all fairly new when I finished and changed careers.

Sounds like you need a good shed to keep your hand in - I also changed career in the '90's but I didn't give up the spanners entirely - nowadays it's much more hobby than income necessity. I enjoy it too much to give it away completely! (and spent too many years learning to throw it away!)

[LuciferDarklord]

Hiya Donc.  The Daewoo Leganza had the Family II engine from Holden   Same as Vectra of the same vintage.  I think all those Family II's had issues with valves hitting pistons when the cam belt broke.  

I was thinking last night why the Diesels seem to last longer than petrol.  Have a look at the figure in the scanned text that has the tensile and compression forces on the conrod as the engone goes thru its cycle.  See the power load on the conrod almost balances out the inertial loads.  Now consider a Petrol engine at light loads.  Approaching TDC on compression stroke, the inertial tensile load would far exceed the force from compression/power.  Now consider a Diesel engine at light loads.  Much higher compression pressures, and the fact that the full charge of air (even more so when turbo'd) is admitted to the cylinder each stroke regardless of load.  This would balance out the inertial load much more evenly at light loads in a diesel engine.  Is this the secret?  Any comments?

Lakes, i'm hearing ya about the common knowledge on the taxis doing high k's.  But near on one million from an engine is not that common, most only do about 750k's  Also your thoughts on the two valve heads, I agree they make the engine feel torquey at low revs, but if you look at the torque curve, the velocity of the gases going past the valve the two valve head would reach terminal velocity much sooner than the four valve head.  So - for a two valve head to make more power in the higher RPM, you'd have to go to a bigger valve, hurting low down RPM.  I think the result is that a 2 valve head would have a narrower torque band than a 4 valve.  Where that torque band is achieved is purely up to the size and lift of the valve.  So I guess Ford chose to make torque down low at the sacrifice of high RPM flow.  Again, I'm no expert but this is my gut feeling.

[donc]

Hiya Donc.  The Daewoo Leganza had the Family II engine from Holden  

[Lakes]

one of the reasons i would not have the petrol is its 4 valve i found 4 valve are ok but because of the two exhast valves they need more revs to make TQ thats unless you add a turbo . that Taxi you talked about would be AU model they still used the two valve motor, i had a ute that model i did well over 250,000? and never used or needed to be topped up with oil, then i looked at a new Ute the BA used 4 valve head i drove it but did not feel as good, so tried the three valve V8 now have 205,000k on that and its still runs as good as new

Hiya Lakes - I don't think I've seen you post without at least once mentioning that V8 Ute - it must be your pride and joy! I've owned a few V8's over the years (Torana, 2x Commodores, 351 Falcon and a Landcruiser) and they were fun. Nowadays I prefer my cars to be smaller and nippier (or 4x4), but I still miss the sound and feel of V8 sometimes  Guy next door has one. but i would not trust it to get me there and back  yes those nissans go well!!

Don, thought i would ask you what you thought of the i30 Gear Box? i would expect your Wifes Petrol would have the same 5 speed as my diesel has? i thought at the start i did not like it that much specially the reverse as it never feels that possitive but seems to be improving. what do you think of them?

[Lakes]

Hiya Donc.  The Daewoo Leganza had the Family II engine from Holden   Same as Vectra of the same vintage.  I think all those Family II's had issues with valves hitting pistons when the cam belt broke

Hi evil one,

Not quite the same - from memory the engine used in Korean builds had different valve and ignition timing specs - and I think a different CDI module. There is no doubt both were weak in the top end though.

I was thinking last night why the Diesels seem to last longer than petrol (snip and...).  Any comments?

It's a good theory but IMO the truism of diesels having greater longevity really just relates to the fact early diesels ran at much lower RPM and produced far less power per weight of engine componentry. They just didn't work as hard as a petrol engine. Of course nowadays diesel technology has moved forward to the extent a little diesel powerplant is comparable to a ULP plant... and with comparable performance, comes comparable wear and tear.



Time will tell, but I expect longevity will be about equal - and the determining factors will have little to do with 'diesel or petrol', it will more come down to questions of maintenance and driving habits.

Don, you are probably right m8, just one thing, the diesel does not have ignition, and i have seen pre ignition do a lot of damage to pretol motors specialy high compression motors that don't use good fuel. other than that you are right as more power and TQ equals more wear just the diesel don't need to keep up the rev's like the petrol does, but i notice the CRDi i30 is long stroke i did not check out the 2.0 petrol so not sure what stroke just it makes TQ well up in the rev range.

[LuciferDarklord]

It's a good theory but IMO the truism of diesels having greater longevity really just relates to the fact early diesels ran at much lower RPM and produced far less power per weight of engine componentry. They just didn't work as hard as a petrol engine. Of course nowadays diesel technology has moved forward to the extent a little diesel powerplant is comparable to a ULP plant... and with comparable performance, comes comparable wear and tear.

Time will tell, but I expect longevity will be about equal - and the determining factors will have little to do with 'diesel or petrol', it will more come down to questions of maintenance and driving habits.

Yeah I reckon you might be right.  Its like arguing about religion, no-one is ever going to have the 100% right answer.  I think the closest people to knowing the answer might be a reliability engineer at a major manufacturer.  The places where they have engines on dynos and put them thru their paces for days on end.  I was talking to a guy years ago about the regime the manufacturers put the engines thru.  He was saying they pump cold water and oil thru them.  Start them stone cold and take them (petrol 4cyl) immediately to 5000rpm at full load, run them there for 10 minutes, then shut them off, get them freezing cold again, and do it over and over and over for weeks.  Kind of extreme but I guess in a limited time frame it would accelerate wear.

[EymaTeapot]

That sounds like the kind of treatment that Hemmi"s car would see day to day living in Iceland.