Is diesel a dead end as a technology?
Discussion
I was chatting to a tech in the trade about diesels a couple of weeks ago, and was horrified at what they were saying about the costs of injectors and pumps. Some of the newer ones - as used by VAG and BMW are circa 1k EACH!!!! and as yet are not refurbishable. Some of the pumps being used are £2k new, and that ignores the massive labour cost to extract and replace the unit.
Even when looking at exchange/refurb injectors, the costs mentioned were several hundred pounds per injector; pumps £500-700.
Will we soon see a period where second hand diesels are effectively worthless when they hit the <£8k value as people will just not want to take the risk.
I have to say I was shocked and horrified at what I was told, as the argument for using the DI and common rails etc is emissions, but it's hardly very ecologically sound if you have to scrap entire car because it becomes BER when a new set of injectors are needed.
Even when looking at exchange/refurb injectors, the costs mentioned were several hundred pounds per injector; pumps £500-700.
Will we soon see a period where second hand diesels are effectively worthless when they hit the <£8k value as people will just not want to take the risk.
I have to say I was shocked and horrified at what I was told, as the argument for using the DI and common rails etc is emissions, but it's hardly very ecologically sound if you have to scrap entire car because it becomes BER when a new set of injectors are needed.
Modern petrols are getting good enough that diesels will be pointless. Small capacity turbocharged petrols the manufacturers are moving to will hopefully put the nail in the coffin of diesels in cars.
I'd much rather have a 1.4 turbo petrol that does 140hp and 37mpg than a 1.9 turbo diesel that does 140hp and 45mpg.
Ford's EcoBoost, the newer VAG TSI, and GM's newer small petrol turbos are getting better and better. Even Renault's 1.2TCE is a cracking little engine thats got rid of the 1.4 and 1.6 NA petrols.
I'd much rather have a 1.4 turbo petrol that does 140hp and 37mpg than a 1.9 turbo diesel that does 140hp and 45mpg.
Ford's EcoBoost, the newer VAG TSI, and GM's newer small petrol turbos are getting better and better. Even Renault's 1.2TCE is a cracking little engine thats got rid of the 1.4 and 1.6 NA petrols.
Most people won't pay any attention whatsoever to the cost of replacing the injectors though. Maybe PH'er's but most people won't know any different.
Joe Public see's a motor that's cheap, comfortable to drive, economical and powerful enough to punt about in. Injector costs are unlikely to enter most peoples heads when buying the car.
Joe Public see's a motor that's cheap, comfortable to drive, economical and powerful enough to punt about in. Injector costs are unlikely to enter most peoples heads when buying the car.
tenohfive said:
Most people won't pay any attention whatsoever to the cost of replacing the injectors though. Maybe PH'er's but most people won't know any different.
Joe Public see's a motor that's cheap, comfortable to drive, economical and powerful enough to punt about in. Injector costs are unlikely to enter most peoples heads when buying the car.
Until someone with a 6 pot beemer calls watchdog and presents their bill for 6k's worth of injectors, and 3k for a new pump and labour to fit.Joe Public see's a motor that's cheap, comfortable to drive, economical and powerful enough to punt about in. Injector costs are unlikely to enter most peoples heads when buying the car.
If more companies move towards a lifetime warranty it will be interesting to see what happens.
Doesn't scare me particularily given that most new cars these days have all sorts of tech that can go wrong - never mind fancy engine bits, what about all the computerised gubbins for safety ABS etc?
People will still buy them, they will just make sure they buy from a garage when some type of warranty comes with the car. Look how well E60d values are holding up!
My Volvo spat its injectors at 56k but it was covered under warranty luckily.
I was reading the new V70 brochure and it did occur to me there was an awful lot of technology working in the background, which if it went wrong would come as a complete surprise to the poor owner - "yes that will be £3000 to fix your heating controls, because its all computerised you see".
Doesn't scare me particularily given that most new cars these days have all sorts of tech that can go wrong - never mind fancy engine bits, what about all the computerised gubbins for safety ABS etc?
People will still buy them, they will just make sure they buy from a garage when some type of warranty comes with the car. Look how well E60d values are holding up!
My Volvo spat its injectors at 56k but it was covered under warranty luckily.
I was reading the new V70 brochure and it did occur to me there was an awful lot of technology working in the background, which if it went wrong would come as a complete surprise to the poor owner - "yes that will be £3000 to fix your heating controls, because its all computerised you see".
halo34 said:
PS what I dont get is how we can call diesel a dead end, if smaller turbo petrol engines are the way to go - isnt that just a turbo waiting to go wrong, just on a different fuel type??
Not really. Diesel fuel components are under a hell of a lot more pressure than their petrol equivalent - hence their prohibitive cost to manufacture.halo34 said:
PS what I dont get is how we can call diesel a dead end, if smaller turbo petrol engines are the way to go - isnt that just a turbo waiting to go wrong, just on a different fuel type??
Turbos are pretty reliable now. Most of the small petrol turbos use run of the mill injectors and fuel pumps, not £1k each peizo injectors and £2k high pressure fuel pumps like modern diesels. They also don't have as many EGR and DPF issues as the diesels.
Interesting to hear this brought up. A mate at college who works in a garage was saying the same, that in 10 years it'll have gone full circle, for the reasons listed. Was slightly dubious but it makes sense I guess 
The other problem is the upcommning Euro VI emissions, which means the Diesel engines will need very expensive equipment to pass. This equipment also adds weight. Step forward petrol...
(although Diesel will be very good as a range extender engine, to be used with batteries and electroc motors
(although Diesel will be very good as a range extender engine, to be used with batteries and electroc motors
HellDiver said:
halo34 said:
PS what I dont get is how we can call diesel a dead end, if smaller turbo petrol engines are the way to go - isnt that just a turbo waiting to go wrong, just on a different fuel type??
Turbos are pretty reliable now. Most of the small petrol turbos use run of the mill injectors and fuel pumps, not £1k each peizo injectors and £2k high pressure fuel pumps like modern diesels. They also don't have as many EGR and DPF issues as the diesels.I think the bill when my injectors were changed was around £500 per injector * 5 + fitting.
It is quite startling the amount of people I've overheard mentioning 'bloody egr valve again' or 'that stupid dpf filter thingys gone tits up again' or 'thats its second set of glow plugs this year' when talking about their cars.
Seems the more the car manufacturers try to 'improve' dervs, the less reliable they become.
A good mechanic friend of mine works at a combined Jaguar/Aston dealership, and when he found out my good lady wife had put a small deposit down on a 3 year old Jaaag, the first thing he said was; "You haven't bought the diesel, have you?". When I inquired why, he mentioned that the vast majority of warranty and breakdowns that they dealt with, was with the 2.7 twin-turbo diesel that Jaguar use.
Glad the missus opted for the petrol
Seems the more the car manufacturers try to 'improve' dervs, the less reliable they become.
A good mechanic friend of mine works at a combined Jaguar/Aston dealership, and when he found out my good lady wife had put a small deposit down on a 3 year old Jaaag, the first thing he said was; "You haven't bought the diesel, have you?". When I inquired why, he mentioned that the vast majority of warranty and breakdowns that they dealt with, was with the 2.7 twin-turbo diesel that Jaguar use.
Glad the missus opted for the petrol
Within as little as 3 -5 years and even now to a large degree, the type of fuel you are putting in your car is almost irrelevant to the technology under the bonnet!
ALL engines will have high pressure common rail injection systems, with pressure charging and EGR. Current GDI's are now over 200bar (ok, a lot less than current diesels, but once you're over about 50bar the injector technology is pretty much the same) I suspect that as the number of DI cars grows and the fleet ages, many more sources will appear for "aftermarket" recon/supply of fuel system parts etc. (with a corresponding fall in costs to the man in the street!!)
As managing the combustion process becomes even more critical to the fuel economy and emissions systems there is no way that petrol engines will just stagnate on the current technology level.
The latest downsized pressure charged VGT gasoline engines basically make 100nm/litre (min) between 1500rpm and 6500rpm, and the latest pressure charged DI engines pretty much match that except right at the top of the rpm range (approx max 5.5krpm) They are basically the same engine now. (DI have much better combustion systems to improve burn rate and hence high rpm performance, GDI's now have to make high torque at low rpm (to support downspeeding for max FE) so end up having peakl power moved down, the result, they are meeting in the middle)
The only long term advantage of diesel as a fuel is that as we get to the end of the oil reserves, diesel (without the lighter fractions required in gasoline) is easier to refine from "poorer" grade crudes.
ALL engines will have high pressure common rail injection systems, with pressure charging and EGR. Current GDI's are now over 200bar (ok, a lot less than current diesels, but once you're over about 50bar the injector technology is pretty much the same) I suspect that as the number of DI cars grows and the fleet ages, many more sources will appear for "aftermarket" recon/supply of fuel system parts etc. (with a corresponding fall in costs to the man in the street!!)
As managing the combustion process becomes even more critical to the fuel economy and emissions systems there is no way that petrol engines will just stagnate on the current technology level.
The latest downsized pressure charged VGT gasoline engines basically make 100nm/litre (min) between 1500rpm and 6500rpm, and the latest pressure charged DI engines pretty much match that except right at the top of the rpm range (approx max 5.5krpm) They are basically the same engine now. (DI have much better combustion systems to improve burn rate and hence high rpm performance, GDI's now have to make high torque at low rpm (to support downspeeding for max FE) so end up having peakl power moved down, the result, they are meeting in the middle)
The only long term advantage of diesel as a fuel is that as we get to the end of the oil reserves, diesel (without the lighter fractions required in gasoline) is easier to refine from "poorer" grade crudes.
As said above, the only way that petrol is clawing its way back is by introducing the same reliability concerns that're hurting diesels. It's not a diesel v petrol argument, it's a complexity v simplicity one.
Ultimately, from a given amount of a certain kind of crude oil, you get a certain amount of petrol and a certain amount of diesel so the market (affected by tax levels) will always push things back into some kind of equilibrium.
Ultimately, from a given amount of a certain kind of crude oil, you get a certain amount of petrol and a certain amount of diesel so the market (affected by tax levels) will always push things back into some kind of equilibrium.
Edited by kambites on Monday 18th October 14:27
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