Do I need the expensive gas???

"Raybender" > wrote in message
...
> From my own experience, our 91 octane here in CA is such junk that I will
often get major brand gas that just
> doesn't seem up to par. My 328 runs poorly until I drain that tank and
fill with another brand. Any trip over
> to Nevada or Arizona where I clean the tank of CA gas usually gives me
better mileage and performance - until I
> get home.

Ever try a bottle of octane boost when you get a bad tank? If it helps,
it's a lot cheaper than a new tank of gas.

-Russ.

330xi wrote:
> you do get poorer mileage on lower octane as well, because the higher octane
> burns cooler and longer
> so the engine also get more energy out of the same amount of fuel.
>
> you save nothing by going to a lower octane, you are just fooling yourself
> into believing you are.
>
>

What you say is true, as applied to cars that require the higher octane,
i.e. those with high compression and advanced (or variable) timing.

But for some car engines that have neither high compression nor variable
timing via the ECU, a lower octane gasoline may actually produce more
power and better efficiency.

-Fred W

"dugies25" > wrote in message
news:1_513265_0c6dd3587a443755212f0dcb0d3eb8f7@aut oforumz.com...
>I am pretty new to this "Ultimate Diving Machine" experience. I want
> to treat my car right, but I also don't want to throw money out the
> window when I don't need to. My previous cars have never required
> premium gasoline, but they have never been BMW's either. I read in the
> manul to use 91 octane or above to avoid knocking in the engine. But I
> have also heard reports that unless you are driving a super high
> performance vehicle that your car won't know the difference between
> 87, 89, or 93 octance gasoline. I have a 2003 330 CI, It is the most
> high performance vehicle i have ever owned, but i don't know if it
> qualifies as needing the higher octane gas...and with the gas prices
> today, if it doesn't need it, I could save $5-$10 a week by getting
> the lower gas. What does everyone think? Has anyone had experience
> with knocking in their engine from lower octane gas?
>

Your engine has a knock sensor which will allow 87 octane by retarding the
timing. But your performance and fuel economy will suffer. You might want
to run a few tanks of 87 and scrupulously record your actual mpg (not from
the OBC but miles divided by gallons) - then do the same with 91 or 93
octane & compare the cost. I suspect that you'll discover only a small
price advantage, if any, to using lower octane.

Tom

Somebody wrote:

> "Raybender" > wrote in message
> ...
> > From my own experience, our 91 octane here in CA is such junk that I will
> often get major brand gas that just
> > doesn't seem up to par. My 328 runs poorly until I drain that tank and
> fill with another brand. Any trip over
> > to Nevada or Arizona where I clean the tank of CA gas usually gives me
> better mileage and performance - until I
> > get home.
>
> Ever try a bottle of octane boost when you get a bad tank? If it helps,
> it's a lot cheaper than a new tank of gas.
>
> -Russ.

Now that's a good thought. Must admit that my adversion to putting any
"mystery" additives into the oil or gas for my cars has prevented this thought
from even occuring to me.

Frank

"Raybender" > wrote in message
...
>
>
> Somebody wrote:
>
> > "Raybender" > wrote in message
> > ...
> > > From my own experience, our 91 octane here in CA is such junk that I
will
> > often get major brand gas that just
> > > doesn't seem up to par. My 328 runs poorly until I drain that tank
and
> > fill with another brand. Any trip over
> > > to Nevada or Arizona where I clean the tank of CA gas usually gives me
> > better mileage and performance - until I
> > > get home.
> >
> > Ever try a bottle of octane boost when you get a bad tank? If it helps,
> > it's a lot cheaper than a new tank of gas.
> >
> > -Russ.
>
> Now that's a good thought. Must admit that my adversion to putting any
> "mystery" additives into the oil or gas for my cars has prevented this
thought
> from even occuring to me.

I'm not a big fan of magic in a can either, but I think octane boost is
pretty straightforward chemistry -- if the problem is indeed low octane. If
not, perhaps the octane boost will mask/overcome it regardless.

I also use Gas Line AntiFreeze on a semi-regular basis without fear.

I once "fixed" a Chrysler transmission with leaking seals by using an ATF
seal conditioner... not sure how that one worked out long term though. :-)

-Russ.

On 28 Mar 2005 12:09:25 -0500, dugies25
> wrote:

> I could save $5-$10 a week by getting
>the lower gas. What does everyone think? Has anyone had experience
>with knocking in their engine from lower octane gas?

My 750iL has run fine for years on 87 octane.

"Paul Kopit" > wrote
> On 28 Mar 2005 12:09:25 -0500, dugies25 wrote:
>
>> I could save $5-$10 a week by getting
>>the lower gas. What does everyone think? Has anyone had experience
>>with knocking in their engine from lower octane gas?
>
> My 750iL has run fine for years on 87 octane.

But your 5.0L V12 is an old, two-valve low-compression design,
and the OP has a new high-compression engine.

Now, if you had an 850csi with the tuner V12 that required premium...

Floyd

On 28 Mar 2005 12:09:25 -0500, dugies25
> wrote:

>I am pretty new to this "Ultimate Diving Machine" experience. I want
>to treat my car right, but I also don’t want to throw money out the
>window when I don’t need to. My previous cars have never required
>premium gasoline, but they have never been BMW’s either.

Gosh, you're the FIRST PERSON EVER to ask about octane on USENET!

Good thing you didn't waste your time doing a google search!

Raybender wrote:
>
> Somebody wrote:
>
>
>>"Raybender" > wrote in message
...
>>
>>>From my own experience, our 91 octane here in CA is such junk that I will
>>
>>often get major brand gas that just
>>
>>>doesn't seem up to par. My 328 runs poorly until I drain that tank and
>>
>>fill with another brand. Any trip over
>>
>>>to Nevada or Arizona where I clean the tank of CA gas usually gives me
>>
>>better mileage and performance - until I
>>
>>>get home.
>>
>>Ever try a bottle of octane boost when you get a bad tank? If it helps,
>>it's a lot cheaper than a new tank of gas.
>>
>>-Russ.
>
>
> Now that's a good thought. Must admit that my adversion to putting any
> "mystery" additives into the oil or gas for my cars has prevented this thought
> from even occuring to me.
>

That and the octane boost stuff costs more than the ~ 10 cents per
gallon more that you would pay at the pump for the higher grade fuel in
the first place.

-Fred W

"Malt_Hound" > wrote in message
...
> Raybender wrote:
> >
> > Somebody wrote:
> >
> >
> >>"Raybender" > wrote in message
> ...
> >>
> >>>From my own experience, our 91 octane here in CA is such junk that I
will
> >>
> >>often get major brand gas that just
> >>
> >>>doesn't seem up to par. My 328 runs poorly until I drain that tank and
> >>
> >>fill with another brand. Any trip over
> >>
> >>>to Nevada or Arizona where I clean the tank of CA gas usually gives me
> >>
> >>better mileage and performance - until I
> >>
> >>>get home.
> >>
> >>Ever try a bottle of octane boost when you get a bad tank? If it helps,
> >>it's a lot cheaper than a new tank of gas.
> >>
> >>-Russ.
> >
> >
> > Now that's a good thought. Must admit that my adversion to putting any
> > "mystery" additives into the oil or gas for my cars has prevented this
thought
> > from even occuring to me.
> >
>
> That and the octane boost stuff costs more than the ~ 10 cents per
> gallon more that you would pay at the pump for the higher grade fuel in
> the first place.

Of course, otherwise everybody would just use that instead of buying
premium. But, as a spot fix for a bad tank of gas, it's much cheaper than
draining and refilling.

-Russ.