why would I do that? I have an oil in RLI that outperforms 502 oils by a factor of 2:1 on Fe wear, even with a 10K OCI. If you'd like to try the comparison between RLI and Delvac in your engine, you're more than welcome to.
RLI Biosyn 5W40, Audi RS4 update
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You've done some good work here. There will be those with fuel dilution issues who'll use this information to their advantage. Thanks a lot for sharing your results. As the owner of an RX8 and Acura RDX I know I have them.
I'm not sure it'll apply to the RX8 (the synthetic vs. mineral oil debate continues with RX8's) but I've passed on your work to those I know who have tuned A3's and WRX STi's who will benefit from this information.
Quality job.
I'm not sure it'll apply to the RX8 (the synthetic vs. mineral oil debate continues with RX8's) but I've passed on your work to those I know who have tuned A3's and WRX STi's who will benefit from this information.
Quality job.
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Originally Posted By: RI_RS4
why would I do that? I have an oil in RLI that outperforms 502 oils by a factor of 2:1 on Fe wear, even with a 10K OCI. If you'd like to try the comparison between RLI and Delvac in your engine, you're more than welcome to.
No need, I have a good friend running it in his PD TDI.
I was more curious as to why it wasn't in the list of tested oils, that's all, as it's results in the PD TDI's has been very good. Not apples to apples obviously but still.
why would I do that? I have an oil in RLI that outperforms 502 oils by a factor of 2:1 on Fe wear, even with a 10K OCI. If you'd like to try the comparison between RLI and Delvac in your engine, you're more than welcome to.
No need, I have a good friend running it in his PD TDI.
I was more curious as to why it wasn't in the list of tested oils, that's all, as it's results in the PD TDI's has been very good. Not apples to apples obviously but still.
OverK1ll
Not even close. The diesel and gasoline DI engines are totally different in design and metallurgy.
Not even close. The diesel and gasoline DI engines are totally different in design and metallurgy.
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Sure, diesel and gas service are miles apart when it comes to the effects on longevity. Synthetic HDEO is a tough sell unless you're doing mega mileage or are in some really extreme cold region.
Delvac 1 is an outstanding oil ..nearly bulletproof in most services ..gas or diesel. If I was searching for a suitable oil for anything that sensibly needed that grade, D1 would surely be on the list regardless of what Teutonic number wasn't on it's spec sheet.
None of this is to discount the suitability or sensibility of RLI lubes in your situation..but there were a few avenues that you didn't explore that apparently revolved around those same little numbers. RLI doesn't carry them either ..but asserts that they're formulated to meet them. Nothing wrong with that. It's what Amsoil does for many of their oils.
Delvac 1 is an outstanding oil ..nearly bulletproof in most services ..gas or diesel. If I was searching for a suitable oil for anything that sensibly needed that grade, D1 would surely be on the list regardless of what Teutonic number wasn't on it's spec sheet.
None of this is to discount the suitability or sensibility of RLI lubes in your situation..but there were a few avenues that you didn't explore that apparently revolved around those same little numbers. RLI doesn't carry them either ..but asserts that they're formulated to meet them. Nothing wrong with that. It's what Amsoil does for many of their oils.
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Originally Posted By: RI_RS4
OverK1ll
Not even close. The diesel and gasoline DI engines are totally different in design and metallurgy.
Gary's response above was pretty much why I asked.
OverK1ll
Not even close. The diesel and gasoline DI engines are totally different in design and metallurgy.
Gary's response above was pretty much why I asked.
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There has been much information dispersed here which has given some good reading. I am certain that everyone here knows that the dilution issue is not a oil issue.
Since the dilution issues are common only to various geographic regions, the manufacturer of the particular vehicle of discussion has isolated the dilution issue to the fuel formulations being used. It has been noted and monitored for verification that some fuels are formulated with higher boiling components which naturally causes fuel to condense on the cylinder walls. This is what is leading to the fuel dilution issues. Use a different fuel formulation and the dilution issue will go away.
If time and money allow, it is adviseable to sample as many different brands and octane ratings as possible and watch the oil samples fluctuate.
Since the dilution issues are common only to various geographic regions, the manufacturer of the particular vehicle of discussion has isolated the dilution issue to the fuel formulations being used. It has been noted and monitored for verification that some fuels are formulated with higher boiling components which naturally causes fuel to condense on the cylinder walls. This is what is leading to the fuel dilution issues. Use a different fuel formulation and the dilution issue will go away.
If time and money allow, it is adviseable to sample as many different brands and octane ratings as possible and watch the oil samples fluctuate.
Has there been any work done on improving fuel combustion in these DI gas engines? Has anyone tinkered with fuel additives to see if fuel dilution could be lowered this way? I was thinking that RLI Biosyn or LCD FP+ might be good ones to try first. Also, octane levels might be worth experimenting with (91-96).
Originally Posted By: INDYMAC
Has there been any work done on improving fuel combustion in these DI gas engines? Has anyone tinkered with fuel additives to see if fuel dilution could be lowered this way? I was thinking that RLI Biosyn or LCD FP+ might be good ones to try first. Also, octane levels might be worth experimenting with (91-96).
Indymac,
The answer to your question is, yes. I cannot disclose more than that, as it is covered by non-disclosure agreement with Terry.
Has there been any work done on improving fuel combustion in these DI gas engines? Has anyone tinkered with fuel additives to see if fuel dilution could be lowered this way? I was thinking that RLI Biosyn or LCD FP+ might be good ones to try first. Also, octane levels might be worth experimenting with (91-96).
Indymac,
The answer to your question is, yes. I cannot disclose more than that, as it is covered by non-disclosure agreement with Terry.
I am aware of Terry's secret additive for fuel efficiency (combustion). I was just wondering if your data takes that formula into account, or was it not used in order to reduce variables.
Thanks for all your valuable work RI_RS4.
Thanks for all your valuable work RI_RS4.
Indy
Some owners use the formula. Some do not. Some have not reported whether they are using it. And ... like an idiot, I've not recorded it in the collected data. Both are reflected in the data. A difference in dilution and nitration can be seen when the formula is used in my case, and in a couple of cases that I know where it was used and not used.
Another interesting data point. No one that uses the Terry Dyson additive has reported a misfire in the past year. This is important, considering that these FSI engines have a propensity to misfire for various fuel and deposit formation reasons.
Some owners use the formula. Some do not. Some have not reported whether they are using it. And ... like an idiot, I've not recorded it in the collected data. Both are reflected in the data. A difference in dilution and nitration can be seen when the formula is used in my case, and in a couple of cases that I know where it was used and not used.
Another interesting data point. No one that uses the Terry Dyson additive has reported a misfire in the past year. This is important, considering that these FSI engines have a propensity to misfire for various fuel and deposit formation reasons.
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Originally Posted By: RI_RS4
.............Unfortunately, since all manufacturers are striving for better fuel economy and emissions, and direct injection improves fuel economy by 5-10% over manifold injection, all will eventually be forced to go to direct injection, and will most likely experience higher fuel levels in the oil......................
The Stop/Start systems being adopted as fuel savers may also lead to increased fuel dilution. As an example, take a look at Mazda's plans:
".......The automaker's goal will also be realized through the use of its new proprietary Smart Idle Stop System that will debut on one of its products in 2009. Unlike other systems, the Mazda start-stop setup injects fuel directly into the cylinder after the engine has shut down and then ignites the fuel to force the piston down.........."
Injecting fuel after the engine has shut down at every stoplight seems like a sure fire way to increase fuel in the oil.
.............Unfortunately, since all manufacturers are striving for better fuel economy and emissions, and direct injection improves fuel economy by 5-10% over manifold injection, all will eventually be forced to go to direct injection, and will most likely experience higher fuel levels in the oil......................
The Stop/Start systems being adopted as fuel savers may also lead to increased fuel dilution. As an example, take a look at Mazda's plans:
".......The automaker's goal will also be realized through the use of its new proprietary Smart Idle Stop System that will debut on one of its products in 2009. Unlike other systems, the Mazda start-stop setup injects fuel directly into the cylinder after the engine has shut down and then ignites the fuel to force the piston down.........."
Injecting fuel after the engine has shut down at every stoplight seems like a sure fire way to increase fuel in the oil.
Originally Posted By: INDYMAC
Has there been any work done on improving fuel combustion in these DI gas engines? Has anyone tinkered with fuel additives to see if fuel dilution could be lowered this way? I was thinking that RLI Biosyn or LCD FP+ might be good ones to try first. Also, octane levels might be worth experimenting with (91-96).
FWIW, Based on recommendations on this forum I started using FP Plus in my 2.0T FSI engine about 6 months ago. While I think the engine is smoother and more responsive, my fuel dilution remained constant at 1.42% between UOAs. Fuel used was Sunoco Ultra 93 almost exclusively.
Has there been any work done on improving fuel combustion in these DI gas engines? Has anyone tinkered with fuel additives to see if fuel dilution could be lowered this way? I was thinking that RLI Biosyn or LCD FP+ might be good ones to try first. Also, octane levels might be worth experimenting with (91-96).
FWIW, Based on recommendations on this forum I started using FP Plus in my 2.0T FSI engine about 6 months ago. While I think the engine is smoother and more responsive, my fuel dilution remained constant at 1.42% between UOAs. Fuel used was Sunoco Ultra 93 almost exclusively.
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Originally Posted By: G-MAN
Originally Posted By: RI_RS4
Similar problems occured with the introduction of DI in diesel engines. It was solved with fuel lubricity enhancement and modifications to oil formulations.
Huh? I don't buy that at all.
I don't support you - I actually agree with RI_RS4.
Originally Posted By: G-MAN
First, "direct" injection has always been the way fuel is delivered in a diesel (with or without a pre-chamber).
Sorry, but that is just not correct. On a diesel engine, when the injector outlet is sited in the main combustion chamber, then this is known as "Direct Injection". However, when the injector outlet tip is sited in a remote chamber (or pre-chamber as you incorrectly state), then this is known as "Indirect Injection".
Originally Posted By: G-MAN
Second, unlike with a gas DI engine, on a diesel, the injectors fire BTDC at the end of the compression stroke, so virtually none of the cylinder wall is exposed to the spray.
Not completely true. On modern diesels with common rail, electronically controlled diesel injection and piezo injectors, the injectors can pulse-"fire" upto around five times per cycle on each cylinder - and this can be before or after TDC.
Originally Posted By: G-MAN
On a gas DI engine, the injectors fire ATDC on the intake stroke, so the potential for cylinder wash-down is great.
Not at all true. On all Volkswagen Group FSI engines (along with their forced induction derivatives such as TFSI and TSI), the injection process follows the same priciples as common rail/piezo diesels. Sadly you show little understanding of the combustion process in internal combustion engines - and specifically the FSI engines, whereby the main pulse of injector operation will be just before the spark timing (always before TDC), with the FSI engine also using a specific post-spark injection to improve emmissions and prevent overheating of the combustion chamber.
Originally Posted By: G-MAN
Also, on a diesel, combustion propagates outward from the injector, so that also lessens the potential for cylinder wall wash-down vs a gas DI engine.
Again, not completely correct. On both petrol and diesel engines, under "correct" combustion, the combustion process will always start from, and propogate outwards from the source of ignition. So on a spark engine (petrol), this will be from the spark plug, and for a compression ignition engine (diesel), this will be the outlet tip of the injector.
The real issue regarding fuel dilution on FSI engines - which is NOT a common problem in Europe, is simply down to the fact that North American (US, Canada & Mexico) variants of FSI engines do NOT utilise the "stratified" or lean-burn mode of fuel injection. It is this element of over-fueling which seems to be the root cause of fuel dilution issues in North American FSI engines.
Originally Posted By: RI_RS4
Similar problems occured with the introduction of DI in diesel engines. It was solved with fuel lubricity enhancement and modifications to oil formulations.
Huh? I don't buy that at all.
I don't support you - I actually agree with RI_RS4.
Originally Posted By: G-MAN
First, "direct" injection has always been the way fuel is delivered in a diesel (with or without a pre-chamber).
Sorry, but that is just not correct. On a diesel engine, when the injector outlet is sited in the main combustion chamber, then this is known as "Direct Injection". However, when the injector outlet tip is sited in a remote chamber (or pre-chamber as you incorrectly state), then this is known as "Indirect Injection".
Originally Posted By: G-MAN
Second, unlike with a gas DI engine, on a diesel, the injectors fire BTDC at the end of the compression stroke, so virtually none of the cylinder wall is exposed to the spray.
Not completely true. On modern diesels with common rail, electronically controlled diesel injection and piezo injectors, the injectors can pulse-"fire" upto around five times per cycle on each cylinder - and this can be before or after TDC.
Originally Posted By: G-MAN
On a gas DI engine, the injectors fire ATDC on the intake stroke, so the potential for cylinder wash-down is great.
Not at all true. On all Volkswagen Group FSI engines (along with their forced induction derivatives such as TFSI and TSI), the injection process follows the same priciples as common rail/piezo diesels. Sadly you show little understanding of the combustion process in internal combustion engines - and specifically the FSI engines, whereby the main pulse of injector operation will be just before the spark timing (always before TDC), with the FSI engine also using a specific post-spark injection to improve emmissions and prevent overheating of the combustion chamber.
Originally Posted By: G-MAN
Also, on a diesel, combustion propagates outward from the injector, so that also lessens the potential for cylinder wall wash-down vs a gas DI engine.
Again, not completely correct. On both petrol and diesel engines, under "correct" combustion, the combustion process will always start from, and propogate outwards from the source of ignition. So on a spark engine (petrol), this will be from the spark plug, and for a compression ignition engine (diesel), this will be the outlet tip of the injector.
The real issue regarding fuel dilution on FSI engines - which is NOT a common problem in Europe, is simply down to the fact that North American (US, Canada & Mexico) variants of FSI engines do NOT utilise the "stratified" or lean-burn mode of fuel injection. It is this element of over-fueling which seems to be the root cause of fuel dilution issues in North American FSI engines.
I would look into US emission regulations as a possible cause. In order for a three way catalyst to work to lower NOX emissions, it must operate under reducing conditions. This means fuel rich.
Ed
Ed
Nice work, RI_RS4. I may have to try a round of this in my speed 3 after the 60k powertrain warranty is up. But I do want to try the Delvac offering first. My PP 5W-30 has actually been doing very well, just curious to compare it to some others.
Originally Posted By: Teutonic_Tamer
The real issue regarding fuel dilution on FSI engines - which is NOT a common problem in Europe, is simply down to the fact that North American (US, Canada & Mexico) variants of FSI engines do NOT utilise the "stratified" or lean-burn mode of fuel injection. It is this element of over-fueling which seems to be the root cause of fuel dilution issues in North American FSI engines.
So, what I read somewhere was that lean-burn requires a special catalyst that in turn requires virtually zero-sulfur gasoline. North American fuel, with up to 30 ppm of sulfur, prevents using the special catalyst, which prevents lean-burn, which leads to over-fueling the direct injection engines, regardless of who makes them.
Does anybody here actually know what's going on?
The real issue regarding fuel dilution on FSI engines - which is NOT a common problem in Europe, is simply down to the fact that North American (US, Canada & Mexico) variants of FSI engines do NOT utilise the "stratified" or lean-burn mode of fuel injection. It is this element of over-fueling which seems to be the root cause of fuel dilution issues in North American FSI engines.
So, what I read somewhere was that lean-burn requires a special catalyst that in turn requires virtually zero-sulfur gasoline. North American fuel, with up to 30 ppm of sulfur, prevents using the special catalyst, which prevents lean-burn, which leads to over-fueling the direct injection engines, regardless of who makes them.
Does anybody here actually know what's going on?
jaj,
From my ICE engineering class a few years back, I think you're mostly correct. I'd consider your description of "over fueling" relative though, as DISI and other non-lean burn (more accurately called "stratified charge", IIRC) ICE's are still designed to operate at stoich A/F of about 14.7:1 under most operating conditions, in order for the "standard" catalyst to work properly. But yes, the sulfur content does intefere with the operation of the stratified charge ICE catalysts.
From my ICE engineering class a few years back, I think you're mostly correct. I'd consider your description of "over fueling" relative though, as DISI and other non-lean burn (more accurately called "stratified charge", IIRC) ICE's are still designed to operate at stoich A/F of about 14.7:1 under most operating conditions, in order for the "standard" catalyst to work properly. But yes, the sulfur content does intefere with the operation of the stratified charge ICE catalysts.
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