Octane for 3 Series
 

What are the pros and cons of using lower octane gasoline in a 2005 BMW
3 series? The book calls for 91 octane or higher, but 91 isn't made
anymore, leaving 93 octane as the only option, according to BMW. Has
anyone been using 89 or even 87 octane without any problem? And why not?

Won't be a problem. The ECU should accommodate lower octane and roll back
ignition advance as necessary to insure detonation does not occur. That'll
cost you some power and mileage, perhaps making the 93 octane not such a bad
choice. Oil companies imply that their higher octane fuel has better
additive packages (Shell in particular in their recent ads), perhaps
conducive to cleaner exhaust valves and injectors.
"Olav" > wrote in message
news:BuJSd.29199$ya6.20232@trndny01...
> What are the pros and cons of using lower octane gasoline in a 2005 BMW 3
> series? The book calls for 91 octane or higher, but 91 isn't made anymore,
> leaving 93 octane as the only option, according to BMW. Has anyone been
> using 89 or even 87 octane without any problem? And why not?

You should try and get Sunco they make 91 if there is any of those station
in your area and it does make a difference to use a higher octane not only
you get better performance but in the long run it will pay off.
"Olav" > wrote in message
news:BuJSd.29199$ya6.20232@trndny01...
> What are the pros and cons of using lower octane gasoline in a 2005 BMW
> 3 series? The book calls for 91 octane or higher, but 91 isn't made
> anymore, leaving 93 octane as the only option, according to BMW. Has
> anyone been using 89 or even 87 octane without any problem? And why not?

I don't geddit.

You're talking of an expensive modern car and you ask about using a fuel
that is lower octane than recommended?

As I don't want to make any assumptions I'll let you tell us why you are
asking the question.

DAS

For direct contact replace nospam with schmetterling
---

"Olav" > wrote in message
news:BuJSd.29199$ya6.20232@trndny01...
> What are the pros and cons of using lower octane gasoline in a 2005 BMW 3
> series? The book calls for 91 octane or higher, but 91 isn't made anymore,
> leaving 93 octane as the only option, according to BMW. Has anyone been
> using 89 or even 87 octane without any problem? And why not?

I have been using the mid-grade for years.





"Olav" > wrote in message
news:BuJSd.29199$ya6.20232@trndny01...
> What are the pros and cons of using lower octane gasoline in a 2005 BMW
> 3 series? The book calls for 91 octane or higher, but 91 isn't made
> anymore, leaving 93 octane as the only option, according to BMW. Has
> anyone been using 89 or even 87 octane without any problem? And why not?

"Jeff Strickland" > wrote in message
...
>I have been using the mid-grade for years.
>

That is what is recomended for all 3 of my BMWS (E36M50, E34M60,
E36/7M52).
AKI 89 or better. It's in the owners manual and on the gas caps.

But we still see AKI 91 around here. Some stations have 91 and others
have 93.

If you really want to be anal about it you could pump half and half
and get octane ratings in between. Heck, that's what they do at
Sunoco stations at the pump.

-Fred W

"The Malt Hound" <Malt_Hound@*no spam please*yahoo.com> wrote in message
...
>
> "Jeff Strickland" > wrote in message
> ...
> >I have been using the mid-grade for years.
> >
>
> That is what is recomended for all 3 of my BMWS (E36M50, E34M60,
> E36/7M52).
> AKI 89 or better. It's in the owners manual and on the gas caps.
>

I don't know about the gas caps, it isn't printed on mine nor is it printed
on the inside of the fuel door. The Owner's Manual does say that 91 (RON) is
the preferred fuel, but 89 will work fine, that is what I use. I have never
tried 87.

"Jeff Strickland" > wrote in message
...
>
> "The Malt Hound" <Malt_Hound@*no spam please*yahoo.com> wrote in
> message
> ...
>>
>> "Jeff Strickland" > wrote in message
>> ...
>> >I have been using the mid-grade for years.
>> >
>>
>> That is what is recomended for all 3 of my BMWS (E36M50, E34M60,
>> E36/7M52).
>> AKI 89 or better. It's in the owners manual and on the gas caps.
>>
>
> I don't know about the gas caps, it isn't printed on mine nor is it
> printed
> on the inside of the fuel door.

Strange. All 3 of mine are. Must be a locale thing...

> The Owner's Manual does say that 91 (RON) is
> the preferred fuel, but 89 will work fine, that is what I use. I
> have never
> tried 87.
>

But Jeff, you live in California. Pumps in the US are not identified
with RON. Other parts of the world use the RON number. RON is the
Research Octane Number and is an artificially high number based on
research parameters.

The octane ratings we see are AKI (Anti Knock Index) also known as PON
(Pump Octane Number), which is the average of RON and MON. The short
of it is 89 AKI (mid grade in the US) is most likely at *least* 91
RON.

Also, the use of the word "premium" in BMW owners manuals can be
confusing as it means different things in different parts of the
world. The best bet is to just make sure your fuel meet spec knowing
the RON, MON, PON/AKI situation. Here's a good reference:

http://www.btinternet.com/~madmole/R...RONMONPON.html

-Fred W

"The Malt Hound" <Malt_Hound@*no spam please*yahoo.com> wrote in message
...
>
> of it is 89 AKI (mid grade in the US) is most likely at *least* 91
> RON.
>
I did some research in this topic since I shipped my BMW to Europe couple of
weeks ago and wanted to know what gas I should use there. According to specs
provided by local refining companies, the lowest octane sold in that part of
the Europe (95 RON) equals to 91 PON/AKI.

So, there are local differences in octanes and probably also differences in
user's manual localizations.

BR:Z

"The Malt Hound" <Malt_Hound@*no spam please*yahoo.com> wrote in message
...
>
> "Jeff Strickland" > wrote in message
> ...
> >
> > "The Malt Hound" <Malt_Hound@*no spam please*yahoo.com> wrote in
> > message
> > ...
> >>
> >> "Jeff Strickland" > wrote in message
> >> ...
> >> >I have been using the mid-grade for years.
> >> >
> >>
> >> That is what is recomended for all 3 of my BMWS (E36M50, E34M60,
> >> E36/7M52).
> >> AKI 89 or better. It's in the owners manual and on the gas caps.
> >>
> >
> > I don't know about the gas caps, it isn't printed on mine nor is it
> > printed
> > on the inside of the fuel door.
>
> Strange. All 3 of mine are. Must be a locale thing...
>

I am surprised this information is not on the inside of my fuel door or on
the cap. But, it isn't for whatever the reason might be.



> > The Owner's Manual does say that 91 (RON) is
> > the preferred fuel, but 89 will work fine, that is what I use. I
> > have never
> > tried 87.
> >
>
> But Jeff, you live in California. Pumps in the US are not identified
> with RON. Other parts of the world use the RON number. RON is the
> Research Octane Number and is an artificially high number based on
> research parameters.
>
> The octane ratings we see are AKI (Anti Knock Index) also known as PON
> (Pump Octane Number), which is the average of RON and MON. The short
> of it is 89 AKI (mid grade in the US) is most likely at *least* 91
> RON.
>
You are correct, my pumps do not specify RON. Sorry for my confusion. The
pumps are marked 87, 89, and 91. I use 89.



> Also, the use of the word "premium" in BMW owners manuals can be
> confusing as it means different things in different parts of the
> world. The best bet is to just make sure your fuel meet spec knowing
> the RON, MON, PON/AKI situation. Here's a good reference:
>
> http://www.btinternet.com/~madmole/R...RONMONPON.html
>

I have only known Premium to mean the highest grade available.