Petrol type poll for GTI owners ::please vote::

**Corey_R** · 13-05-2010, 08:32 PM

@prise, whilst I'm not scientific or mechnically minded enough to argue with you, both Mercedes and BMW disagree with you. Both companies are unable to bring petrol engines to Australia due to our sulphur content in premium petrol.

**hooba** · 13-05-2010, 08:39 PM

They cannot bring the engines simply because Euro 5 requires that the emissions at 100,000kms is not different to when the engine was brand new. The current sulphur content means that they can't comply over 100,000kms.

A point that is being missed is that in order to upgrade the refineries in order to lower the sulphur content is that it will cost $$$. The oil companies won't wear that, it will be passed on to the consumer.

**Diesel_vert** · 13-05-2010, 08:47 PM

That's what they said about Euro 2 (500 ppm), Euro 3 (150 ppm), Euro 4 (50 ppm), and now Euro 5 (10 ppm).

Without advanced fuels there can be no advanced engines and technologies.

**prise** · 13-05-2010, 08:57 PM

Coreying, I don't disagree with you. My point is that its the catalytic converter that will suffer rather than the engine itself. Euro 5 compliant vehicles are required to be self diagnosing of emission compliance which is why lambda sensors are now fitted before and after the catalyst. When the catalyst 'wears out', a check engine light will come on. This is not 'engine damage' per-se but is still undesirable given the cost of replacing a catalytic converter runs into the high hundreds of dollars. It is understandable why some manufacturers will adopt a wait and see approach if they are unsure about the longevity of their catalysts with 50ppm of sulphur in the fuel.

If the vehicles you refer to that can't be imported here are using true lean burn technology then that would make sense. They would have to use whats known as a NOx storage catalyst that stores the excess NOx produced when the engine runs lean and then converts it later when a normal mixture is used. Such catalysts are very sensitive to sulphur and would require <10ppm for the catalyst to last 100000 km. I don't think the Golf uses lean burn based on what I've seen coming across the OBDII port as the lambda didn't seem to go above 1 for an length of time. Hopefully the VW golf being a true 'world car' has been engineered to provide adequate life in the catalyst with our 50ppm fuel.

With the increasing number of Euro 4 and 5 compliant cars on our roads we are going to see a lot of check engine lights as the fleet ages. In the absence of annual emissions testing, I suspect most owners will ignore the light when they find out how much a replacement catalyst costs.

**Corey_R** · 13-05-2010, 09:21 PM

Originally Posted by hooba

They cannot bring the engines simply because Euro 5 requires that the emissions at 100,000kms is not different to when the engine was brand new. The current sulphur content means that they can't comply over 100,000kms.

No... they cannot bring the engines due to damage that the sulphur will cause to them during the lean burn processes which the engines use to save fuel over the previous generation engines!

**cameronp** · 13-05-2010, 09:36 PM

Originally Posted by coreying

No... they cannot bring the engines due to damage that the sulphur will cause to them during the lean burn processes which the engines use to save fuel over the previous generation engines!

AFAIK "lean burn", "direct injection" and "fuel stratified injection" all mean the same thing. It might be that with lower-sulfur fuel, it's possible to tune the engine to run more efficiently, though - I don't understand the specifics of the process well enough to know what that would involve.

All of the VW engines mentioned here were introduced when Euro4 standards (50ppm sulfur, same as current Australian regulations) were current in Europe, and some are sold in the USA which has even less stringent requirements on sulfur content of fuel.

Having said all of this, regulations to reduce sulfur content in fuel can only be a good thing, and it would great to see Australia keep up with Europe in emissions and fuel quality standards.

**hooba** · 13-05-2010, 09:37 PM

Originally Posted by coreying

No... they cannot bring the engines due to damage that the sulphur will cause to them during the lean burn processes which the engines use to save fuel over the previous generation engines!

I'm going on the article that you quoted the other day.

2011 M-Class faces fuel issues in Oz

**Corey_R** · 13-05-2010, 09:41 PM

Fair enough.... I've been trying to find an old one that I read from BMW too, but can't right now.

**prise** · 14-05-2010, 02:54 PM

Originally Posted by cameronp

AFAIK "lean burn", "direct injection" and "fuel stratified injection" all mean the same thing.

Just having direct injection does not enable lean burn. The combustion chamber also has to be designed to provide a richer mixture at the spark plug and the exhaust system has to be able to clean up the large quantities of nitrous oxides produced by the high combustion temperatures. The expensive exhaust treatment required to clean up the NOx has limited the application to date. I know that my previous car (Mazda 6MPS 2.3 L turbo DISI) which was direct injected did not utilise lean burn and that the holden commodore SIDI engine also does not as both engines run with a lambda of 1.0 on light throttle.

The higher cost of the exhaust treatment required to reduce the NOx is probably easier to absorb in the cost of a more upmarket vehicle such as a BMW and MB.

The quickest way to see if a car is running lean burn is to plug into the OBDII terminal and monitor the lambda value achieved at light throttle openings on a level road. If its a lambda of 1.0 then you can be fairly sure its not using lean burn.