93 Octane

[Stock4Evr]

Is 93 Octane from Shell the same as 93 Octane from other brands? I realize that the difference may just be the amount and type of additives added, but would that be all? I normally use Exxon as it is very convenient.

[PA135i]

You pretty much answered your own question. It's the additives. Shell is excellent gasoline for our cars. I believe they have the highest amount of additives for the gasolines that qualify for Top Tier rating. Exxon also is Top Tier and excellent gasoline.
I buy Costco which is Top Tier but is on average 15 - 20 cents a gallon cheaper than the Shell stations near me. And since it is a Top Tier it is fine for my 1er. It does have less additives than Shell but still qualifies as Top Tier.

[Stock4Evr]

Originally Posted by PA135i

You pretty much answered your own question. It's the additives. Shell is excellent gasoline for our cars. I believe they have the highest amount of additives for the gasolines that qualify for Top Tier rating. Exxon also is Top Tier and excellent gasoline.
I buy Costco which is Top Tier but is on average 15 - 20 cents a gallon cheaper than the Shell stations near me. And since it is a Top Tier it is fine for my 1er. It does have less additives than Shell but still qualifies as Top Tier.

Thank you for verifying my thoughts. As the Exxon is right on my way, convenient entry and exit and no waiting I will stay with their 93 Octane. All the shell stations are out of my way. I did not know that Costco was Top Tier and will look into their stations. Tks again.

[rhodesman]

what about E10 vs. pure? Is Shell any better at having pure fuel or is everything pretty much E10 these days?

[TheFox]

The additives in the gas shouldn't make any difference as most of them are just detergents designed to clean the intake after the injectors. Needless to say direct injection engines like ours do not get a benefit from most of these additives..

Originally Posted by rhodesman

what about E10 vs. pure? Is Shell any better at having pure fuel or is everything pretty much E10 these days?

I too am very interested in who would be best for less E10 content...

[135TX]

Originally Posted by TheFox

The additives in the gas shouldn't make any difference as most of them are just detergents designed to clean the intake after the injectors. Needless to say direct injection engines like ours do not get a benefit from most of these additives..



I too am very interested in who would be best for less E10 content...

Given our high compression, boosted engine wouldn't you want more E content?

Like the people running E85 & 93 mix?

[TheFox]

Originally Posted by 135TX

Given our high compression, boosted engine wouldn't you want more E content?

Like the people running E85 & 93 mix?

I would prefer running ethanol on a separate system to ensure that I don't have to worry about deterioration of the fuel lines. I also live at 5000ft above sea level and don't have to worry about knocking and detonation as much but only have access to 91 or 100 octane no 93 within 200 miles.

[135TX]

Originally Posted by TheFox

I would prefer running ethanol on a separate system to ensure that I don't have to worry about deterioration of the fuel lines. I also live at 5000ft above sea level and don't have to worry about knocking and detonation as much but only have access to 91 or 100 octane no 93 within 200 miles.

100 octane is gnarly, how much does that cost per gallon?

[hyphy1]

are you suggesting we all might as well go with the "cheaper" gas?

Originally Posted by TheFox

The additives in the gas shouldn't make any difference as most of them are just detergents designed to clean the intake after the injectors. Needless to say direct injection engines like ours do not get a benefit from most of these additives..



I too am very interested in who would be best for less E10 content...

[Dackelone]

Originally Posted by rhodesman

what about E10 vs. pure? Is Shell any better at having pure fuel or is everything pretty much E10 these days?

IF you can find fuel without any ethanol - then that's what I would buy. Ethanol just dilutes the fuel power and adds a way that water can get into your engine. Plus the ethanol will corrode the fuel system over time. I prefer my fuel pure.

[TheFox]

Originally Posted by hyphy1

are you suggesting we all might as well go with the "cheaper" gas?

Not necessarily, I don't recommend anything under 90 octane but you don't need premium 93 with "Special" additives (detergents) if you can find it for less without the additives.

Originally Posted by 135TX

100 octane is gnarly, how much does that cost per gallon?

Its between 5-8$ a gallon depending on the stock the shop I go to has.

[BMW135pls]

Originally Posted by Dackelone

IF you can find fuel without any ethanol - then that's what I would buy. Ethanol just dilutes the fuel power and adds a way that water can get into your engine. Plus the ethanol will corrode the fuel system over time. I prefer my fuel pure.

This is what I thought as well, then I realized that E85 really is as awesome as people say it is. So if mixing E85 in with E10 93 pump gas is a good thing, then why would E10 93 be a bad thing over E0 93?

[hyphy1]

Originally Posted by TheFox

Not necessarily, I don't recommend anything under 90 octane but you don't need premium 93 with "Special" additives (detergents) if you can find it for less without the additives.

[ShocknAwe]

Originally Posted by Dackelone

IF you can find fuel without any ethanol - then that's what I would buy. Ethanol just dilutes the fuel power and adds a way that water can get into your engine. Plus the ethanol will corrode the fuel system over time. I prefer my fuel pure.

It won't do anything to the fuel system over time. The only thing that I can think of happening is as the rubber seals deteriorate, the water content in the ethanol could get in there and freeze in low temps, making the cracks worse. They should be replaced at that point anyways. But it will not break anything down by virtue of using it. The issues that fuel pumps have (sometimes, and really only at E40-E50) is due to specific gravity.

Water in the fuel also helps cool down combustion temps. We're talking very very low amounts that atomizes well. Like in water injection. I've heard wall-wetting thrown around a little here and there, but I'm not sure how much of an issue that is with our direct injection system vs the port injection of the past.

Originally Posted by BMW135pls

This is what I thought as well, then I realized that E85 really is as awesome as people say it is. So if mixing E85 in with E10 93 pump gas is a good thing, then why would E10 93 be a bad thing over E0 93?

If you wanted to play octane games, do this:

If you mix 9 gallons E0 93 with 4 gallons E85, you get ~97 octane and E26, which is much easier on your LPFP than the E33 mixture that you get if you use E10 93 instead.

8 gallons E0 with 5 gallons E85, closer to 98 octane and E33, vs E39 with E10.

Though, I think the extra money to buy E0 gas would ultimately pay for a FuelIt stg2 pump very quickly. It's almost $1.50 per gallon more at the one station that sells E0 93 here.

Good link: http://www.intercepteft.com/calc.html

[Dackelone]

Originally Posted by ShocknAwe

It won't do anything to the fuel system over time. The only thing that I can think of happening is as the rubber seals deteriorate, the water content in the ethanol could get in there and freeze in low temps, making the cracks worse. They should be replaced at that point anyways. But it will not break anything down by virtue of using it. The issues that fuel pumps have (sometimes, and really only at E40-E50) is due to specific gravity.

Water in the fuel also helps cool down combustion temps. We're talking very very low amounts that atomizes well. Like in water injection. I've heard wall-wetting thrown around a little here and there, but I'm not sure how much of an issue that is with our direct injection system vs the port injection of the past.

I don't buy that. Ethanol allows water to attach to it. Hence it can get further down the fuel system and cause damage/corrosion. When the E10 and E05 fuels started to come out in Germany(2011)... even BMW(and other car makers) were telling us different things. Some said within the company its ok, but the engineers said it was not good over the long term.

Sulfur free gas and the new E10 fuel in Germany…
http://www.1addicts.com/forums/showthread.php?t=485903

Today most German gas stations sell the regular blend fuel, which is E10(10% ethanol) 95 octane, called: Super. Then they have another Super with is also 95 octane but only has 5%, called E05 Super. And then we have our premium fuel called SuperPlus 98 octane which as NO ethanol.

I only use 98 octane SuperPlus in my car.

[kprocivic]

Originally Posted by 135TX

100 octane is gnarly, how much does that cost per gallon?

8.79 here in socal. I'm getting tired of mixing it with 91 to make 93.

[135TX]

Originally Posted by Dackelone

I don't buy that. Ethanol allows water to attach to it. Hence it can get further down the fuel system and cause damage/corrosion. When the E10 and E05 fuels started to come out in Germany(2011)... even BMW(and other car makers) were telling us different things. Some said within the company its ok, but the engineers said it was not good over the long term.

Sulfur free gas and the new E10 fuel in Germany…
http://www.1addicts.com/forums/showthread.php?t=485903

Today most German gas stations sell the regular blend fuel, which is E10(10% ethanol) 95 octane, called: Super. Then they have another Super with is also 95 octane but only has 5%, called E05 Super. And then we have our premium fuel called SuperPlus 98 octane which as NO ethanol.

I only use 98 octane SuperPlus in my car.

Tots jelly. I want 98 octane.

[BMW135pls]

Originally Posted by 135TX

Tots jelly. I want 98 octane.

They're on the RON scale there. 98RON is equivalent to 93RM2.

[135TX]

Originally Posted by BMW135pls

They're on the RON scale there. 98RON is equivalent to 93RM2.

Oh yeah I forgot the conversion! Well my 93 (e10 max) for $2.89 isn't bad then

[Dackelone]

Originally Posted by 135TX

Tots jelly. I want 98 octane.

Originally Posted by BMW135pls

They're on the RON scale there. 98RON is equivalent to 93RM2.

Yep, our 98 is equivalent to 93 in the states. We can also get/buy 100 or 102 at some gas stations like Aral(owned by BP) and Shell. When I use 10/102 you can really feel how much smoother the engine runs/pulls.

Dack

[Stock4Evr]

Thanks to all who commented on this subject. They were very informative and helpful. From what I gather, running just a stock 135i, I can use 90 Octane with no loss of power or cleaning.

[ShocknAwe]

Originally Posted by Dackelone

I don't buy that. Ethanol allows water to attach to it. Hence it can get further down the fuel system and cause damage/corrosion. When the E10 and E05 fuels started to come out in Germany(2011)... even BMW(and other car makers) were telling us different things. Some said within the company its ok, but the engineers said it was not good over the long term.

Sulfur free gas and the new E10 fuel in Germany…
http://www.1addicts.com/forums/showthread.php?t=485903

Today most German gas stations sell the regular blend fuel, which is E10(10% ethanol) 95 octane, called: Super. Then they have another Super with is also 95 octane but only has 5%, called E05 Super. And then we have our premium fuel called SuperPlus 98 octane which as NO ethanol.

I only use 98 octane SuperPlus in my car.

Here's one of the posts I was alluding to. I'll try to find the others. All comments are on the N54 itself and fueling capacities. Interview with an unnamed VDO Continental engineer.

Today i had my follow up conversation with the tech guy at continental. Here are the questions and answers. Enjoy !

Are the pistons forged pistons ?
- Don’t know

Does the N54B30 use homogenous or stratified charge under high load ?
- The engine was developed to run in homogenous mode. The N53 engine was to run in a stratified mode. Although the engine is capable of running in stratified mode, it currently does not.
It uses an outward opening injector.

Have you experience with this engine and E85 fuel or do you have any thought on it ? Can e.g. the injectors handle alcohol ?
We have a lot of experience with E85. Currently, we have an issue that if the injector is hotter than 100 Celsius, we are seeing melting of the fuel filter in the injectors. As long as the temperature of the injector stays under the 100 Celsius, this engine is perferctly capable to run E85. As a matter of fact, it will run E100 without any problem under cold conditions. There is no need to preheat the fuel.
We are investigating the filter issue, and we hope to have a solution next year. Whether or not we will create injectors for this engine, depends on the market (read: BMW).
It is not possible to replace this filter yourself; you cannot open the injector to get to that part.

Is the HPFP pressure of 90 bar constant or is it controlled by the MSD module ?
It is constant but indeed controlled by the module. The engine has been tested to up to 200 bar. If you keep the HPFP pump below that number, you could inject a lot more fuel. The relation between the amount of fuel sprayed and the pressure is not a linear relation but a Bernulli equation.

In our earlier conversion, you mentioned that under high load the TI is about 2 ms ? Correct ?
Yes maximum is 2 ms. Notice that the engine runs under homogenous mode and that means that the injection start in the intake phase. With this engine, it is no problem to keep injection into the compression phase, but not too long; it would be bad for emission. However, if the pressure of the HPFP is increased, this may not be needed.

The injectors have a maximum of 40 mg/ms spray at 200 bar. This is an increadible amount of fuel, much much more than any solenoid injector. It is this high, because when we designed the application, BMW insisted that the engine must be able - in limp mode - to only use the LPFP pressure, which is 5 bar, and still drive the vehicle at 170 km/h.


If correct, do you agree then that considering the ti in the compression phase, we can get it up to 4 ms for 7000 rpm ? Can we use the full compression phase ?

You would have to calculate it, but yes, there is extra time at mentioned before.
The injector can inject a lot of fuel into the cylinder. When increasing the injection time, and also when injecting in the compression phase, look out for cylinder wall wetting. This is dangerous. It would wash away the oil on the walls, causing wear. One way to check for wall wetting is to check the engine oil if it has fuel in it. Another way would be to check if the vapor of the exhaust gas recirculation (EGR) and see if there's fuel vapor.
The risk of wall wetting may be reduced by running higher boost, as it affects air flow inside the cylinder.
Running the HPFP at higher pressure may increase the risk again.

You said we should tune the TI duration of the ignition pulse. Can we also tune with the MSD via a reflesh when the ignition time starts ?
There is indeed a calculated ignitition start time in the MSD. It is not a map, but i'm not sure.

How does the ECU measure a knocking problem ? Does it use voltage ? Does it do it for all 6 cilinders individual ?
Each piezo injector has a knocking sensor. It measures vibration. By looking at certain frequencies, the knocking signal is sent.

EDIT: seems that the engine also has the standard knocking sensors in place.

De community is desperate to lean more about the MSD80. We would love to have information that can help us reflesh the unit to tune to engine for 600 PS. Can you help ? Can you direct us to a colleague (do you have a name ?) This is vital for my own project too !
I don't know about the MSD80. I'm an injection / fuel system engineer. I will talk to some colleagues and see if i can help you with anything. We have to make sure we're not infringing any copyrights and i think BMW owns the rights to the information on the MSD.


Can we buy this information ? Who should I talk to to ?
there may be a legal way to buy this information, i will talk to some colleagues and mail you back.


All of us want to invite you to join our forum N54tech.com. An engineer like you would be incredible value to the forum, may I mail you an invite to join ? It’s free of course !
Thank you for the invitation. I will think about it. I have to be careful not to share information that my company doesn't want us to share.