VW problems

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civvie
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VW problems

Post by civvie »

Not strictly French car but,
You have a VW and you get the offer of having the engine "repaired" to delete this emission testing thingy, would you have it done or leave as is, if you have it done would your fuel consumption go up, plus if you were to travel say on a flat bit of motorway even now before the (fix) with cruise control on could you get into the realms of the car going into test mode again saving fuel.
Just a thought.

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Sloppysod
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Re: VW problems

Post by Sloppysod »

Good question and.......................

On my last C5 (2.2 auto, 03 plate) I added one of those little gizmos you can get to plug into your injector rail, all I can think is that the gizmo reduced the fuel pressure at the injectors so less fuel was injected per 'squirt' of the injector and when the throttle butterfly was opened eamore fuel was drawn in by the vacuum. Now, the benefit was normally an extra 5 mpg, up to 10 mpg on a run, quite often had it in the high 40's, and a little extra ooommph! when I put my foot down. and when it went for its MOT the emissions were virtually '0', in fact once they even run it again as they thought their machine had broke!! - and it still had its original particulate filter when I sold it at 150,000.

So I if I were to own a VW, I would want to know the consequences of any 'fix' and will my VED go up at the same time - which it should if your car crosses the band.

rory_perrett
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Re: VW problems

Post by rory_perrett »

I know its wrong but you have to admire the engineering. At the end of the day, all the ECU does is read a load of data and play with various parameters to ensure that the engine is running at its "optimum". Optimum is deliberately in quotes because what is considered optimum varies depending on what the car is doing or more what the ECU thinks the car is doing.

When you are putting cars through a standard test then by its very nature it must be done in the same way for every car and if you know what that way is then its pretty easy to get the ECU to recognize it for what it is.

Could a car go into test mode under normal driving conditions? Well yes it could if you reproduced whatever the conditions were for the start of the test. Would you notice? Probably not and as soon as you demanded something of the car that pushed the measured parameters outside of the those for the test it would drop out of test mode.

For example, on the test there is no steering wheel input therefore if the ECU knows that the car is running and the wheels are turning but there is no change in the steering position for say 15 sec then there is a chance its on test.

As to what the ECU does: to reduce the NOx emissions which is what the issue is with VW then you need to reduce the combustion temperature in the cylinder. I would guess that on test the EGR valve will be opened most of the time and the fuel injection timing may be altered.

Fixing it to produce less NOx will increase particulates and probably decrease MPG so more CO2 per mile.

But as I said, the figures we all see for cars be they MPG, or C02 per mile, NOx, particle emissions, etc all come from standard tests and bear little resemblance to "real world" activity. In reality we will be changing one lot of artificial numbers for another, these, as always, will be used by some bureaucrat to create a complex tax system to punish or reward, encourage or dissuade some behavior or other and in reality all our cars will continue to chuck as much stuff out of the exhaust pipe as they always did.

And when we've all had enough of a beating and like good little girls and boys we are all driving round in Nissan Leafs it will be the turn of the all electric car to be vilified because suddenly it will be brought to our attention what a terrible environmental disaster the mining, processing and disposal of all the nasties that are need to produce the batteries required is. At the moment it only affects poor, foreign people in far away lands at so we don't have to worry about it for now or until we need another guilt tax visited upon us.

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CitroJim
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Re: VW problems

Post by CitroJim »

A very thoughtful response Rory :)
rory_perrett wrote: And when we've all had enough of a beating and like good little girls and boys we are all driving round in Nissan Leafs it will be the turn of the all electric car to be vilified because suddenly it will be brought to our attention what a terrible environmental disaster the mining, processing and disposal of all the nasties that are need to produce the batteries required is. At the moment it only affects poor, foreign people in far away lands at so we don't have to worry about it for now or until we need another guilt tax visited upon us.
Indeed and quite. This has already been raised in some circles and it's a massive issue which will surely gain currency as time goes on... Batteries have some horrible chemicals in them and disposal of expired batteries is akin to the problem of nuclear waste disposal...

They say that at the present time the greenest, cleanest and most economical approach is the small petrol engine..

A good example being the C1/107.... Having just three cylinders the engine itself saves on raw materials and therefore environmental impact.

Peter.N.
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Re: VW problems

Post by Peter.N. »

While I don't approve of manufacturers or anyone else for that matter lying the fact is that VWs fuel economy is as good or better than most. Whether this 'revelation' has really done them any serious harm or not only time will tell but I wouldn't be surprised if other manufacturers were doing something similar but haven't been found out yet.

Peter

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CitroJim
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Re: VW problems

Post by CitroJim »

Peter.N. wrote:I wouldn't be surprised if other manufacturers were doing something similar but haven't been found out yet.
I think it's very near a certainty Peter...

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Re: VW problems

Post by rory_perrett »

I have a mantra (one of many) which is Tell me how you'll judge me and I will tell you how I will behave. When mpg used to be quoted at 62 mph, guess what, engine performance and gear ratios were tweaked to give maximum fuel economy. I have no doubt that if you drove at 62 mph on a flat road then you would achieve something around the quoted figure, But no one uses a car in that way.

All manufacturers will be focused on passing the test and will tweak things to help the car do so. VW appear to have over stepped the mark, others may have stayed just the "right side" but they will all have engineered the car in some way shape or form.

This is similar to the arguments about drugs in athletics. Drug taking is bad, sleeping in an Oxygen tent is OK, if the drug that is being taken increases the oxygen level in the blood, as does the oxygen tent why are they viewed any differently?

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CitroJim
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Re: VW problems

Post by CitroJim »

rory_perrett wrote: This is similar to the arguments about drugs in athletics. Drug taking is bad, sleeping in an Oxygen tent is OK, if the drug that is being taken increases the oxygen level in the blood, as does the oxygen tent why are they viewed any differently?
And training at altitude... All have the same overall effect...

I believe years ago when engine power outputs were the benchmark of cool and desirable that the engine chosen for the test was 'blueprinted' (i.e. in perfect tolerance and built to perfection) and run without any ancillaries being driven such as alternator and so on...

No production car could ever meet the figures but it looked good on paper, especially advertising paper..

It's no different now, just the definition of cool and desirable has changed... These days for power read CO2 or NoX...

Call me an old cynic about these things and you'll be right!

Like how my C1 just escapes into free tax with 99 g/Km of CO2... Funny that, just one gram below the limit and 1 gram really is a very small quantity... I bet no C1 on the road today actually meets that specification and therefore by rights should be paying some tax!

Peter.N.
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Re: VW problems

Post by Peter.N. »

rory_perrett wrote: I have no doubt that if you drove at 62 mph on a flat road then you would achieve something around the quoted figure, But no one uses a car in that way.
I do and I do :-D

Peter

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Sloppysod
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Re: VW problems

Post by Sloppysod »

CitroJim wrote:A very thoughtful response Rory :)
rory_perrett wrote: A good example being the C1/107.... Having just three cylinders the engine itself saves on raw materials and therefore environmental impact.
I seem to remember a car in the 80's (dihatsu I think) produced a car with the most optimum engine arrangement, 3 cylinders some weird capacity, can not remember what is was - Age again!!
Anyway enjoy the video -



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CitroJim
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Re: VW problems

Post by CitroJim »

Sloppysod wrote: I seem to remember a car in the 80's (dihatsu I think) produced a car with the most optimum engine arrangement, 3 cylinders some weird capacity, can not remember what is was - Age again!!
Ahh yes, the Daihatsu Charade and especially in Turbo guise..

Daihatsu are the acknowledged leaders in 3 pot engines and the Turbo three-pot in the Charade was a wicked little thing :twisted: 8-) They are to little 3 pot petrols as PSA are to diesels :)

Daihatsu are now part of Toyota and in fact the C1/107/Aygo 3-pot engine is a Daihatsu design.. No turbo but it does have VVT and is a remarkable little engine as any C1/107 owner will testify :-D

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Re: VW problems

Post by wurlycorner »

All that was driven by Japanese Kei car rules. Loads of examples of excellent small capacity turbo engines in small Japanese cars, going back decades.

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CitroJim
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Re: VW problems

Post by CitroJim »

wurlycorner wrote:All that was driven by Japanese Kei car rules. Loads of examples of excellent small capacity turbo engines in small Japanese cars, going back decades.
Yes, the little Hondas of the 60s and 70s really epitomised that.. The N and S series...

Super little things and still very desirable even today...

Hell Razor5543
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Re: VW problems

Post by Hell Razor5543 »

I know of somebody who had a little Daihatsu Charade Turbo. 0 - 60 in "Jesus Christ!". The top speed wasn't high (around 100MPH), but it didn't take long getting there. The diesel variant was (IIRC) the first production car to have 100MP/G economy.

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CitroJim
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Re: VW problems

Post by CitroJim »

Wikipedia article on the Daihatsu Charade...

James, yes, it really was a little screamer..

I often wonder what a C1 would be like with the Charade Turbo engine...

Maybe a project one day...