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FAQ part 2/10
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Subject: FAQ part 2/10
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From: "Rick Kjeldsen" <fcmk@domain.elided>
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Date: Tue, 22 Nov 1994 12:48:21 -0500
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Chapter 10.0: Mail-order and other parts stores
This list is highly subjective. It is not an endorsement of any type of any
dealer. The attempt is to list dealers who are a) established(??) b) deal
in special parts/models c) have special/unique incentives and d) offer CCA
discount. Please send me names of dealers whom you feel should be listed
here for the reasons mentioned above.
NAME+PLACE+NUMBER | CCA DISCOUNT | SPECIAL
==============================
California:CA
Bavarian Wrecking: Rancho Cor.. | Free delivery | Salvaged/used/rebuilt parts
800-726-4269
Eurasian: Temecula | ? | catalog
800-824-8814
Peter Pan BMW: San Mateo | Y (25%) | 15% off on remanufactured parts
800-346-9077
World Upholstery: Camarillo | ? | interior parts
800-222-9577
North Hollywood Speedometer | ? | Speedometer cables, etc.
(818) 761-5136
==============================
Indiana:IN
Tire Rack: South Bend | ? | Tires, Wheels
800-428-8355
==============================
Florida:FL
Europroducts: Clearwater | ? |
800-850-0325
==============================
Massachusetts:MA
Foreign Motors: Natick | 20% |
800-338-3198
Greenfield Imported Car Parts | ? |
(413) 774-2819
==============================
Maryland:MD
Maximillian: Baltimore | ? | emphasis on CS and 2002 parts
410-744-2697
==============================
Missouri:MO
Imparts:St. Louis | N | Free shipping > $40
800-325-9043 | catalog
Metric Mechanic: Kansas City | ?
816-231-0604
==============================
New Hampshire:NH
Bavarian Auto Service:Newmarket | Y | catalog
800-535-2002 | Discount not on all items
==============================
Pennsylvania:PA
Bimmer Parts: Pottstown | ? | 2002/Bavaria/320i parts
800-274-2466
AutoGalerie: Sewickly | ? | Videos on BMWs and race cars
412-741-9472 | catalog
==============================
Texas:TX
BMP Design: Tyler | ? | Suspension
800-648-7278
==============================
Virginia:VA
E-Design: Reston | ? | T-shirts
703-391-1606
Freedom Design: Alexandria | ? | styling packages
800-296-1792 | catalog
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Chapter 11.0: Gasoline
Section 11.1: BMW Gasoline Test - Consumer Reports (Summary)
(Editor's note: The following info is now some years old)
A: (by Harvey Chao: harvey_chao@domain.elided)
Someone on Rec.Auto or something close asked about the following article
from Consumers's Report. Since I took the effort to type it up, I may as
well forward it to all of you too.
I found this article while looking in the "Reader's Guide to Periodical
Literature" in my public library when I was researching articles published
in magazines about BMWs. The source is Consumer Reports, Jan 1990 pages 8, 9,
and 10. The following is a summary of their survey;
Withing groups listed alphabetically. Gasolines checked (X) have passed the
"unlimited milage" standards of BMW's test* for preventing the build up of
deposits on valves, acording to the refiners responses to a Consumer Reports
questionaire (see story) Those marked (-) have not passed BMW's test.
Brand Regular Midrange Premium
Amoco X X X
Arco X 1 X
Antlatic _ _ _
BP 2 2 2
Chevron X X X
Citgo 3 3 3
Diamond
Shamrock - - X
Exxon X X X
Fina 4 4 4
Gulf - - -
Hess 4 4 4
Marathon X X X
Mobile X X X
Phillips 66 4 4 4
Shell 5 5 X
Sunoco - - 6
Texaco X X X
Unocal X X X
The following refiners did not respond to our questionnaire. Lacking any
information about the presence or effectiveness of the detergent packages,
we cannot recommend their gasoline for latemodel cars with fuel-injected
engines.
Beacon, Clark, Getty, Kerr-Mcgee.
[1] Midgrade gasoline is not available
[2] According to company, som BP stations sell gasoline that meets BMW
"unlimited milage" requirements and some do not.
[3] Company says new detergent package that will pass BMW "unlimited
milage" test is to be introduced in all three grades in first quarter of
1990, but not necessarily in all three grades.
[4] Company says new detergent package that will pass BMW "unlimited
milage" test is to be introduced in all three grades in first quarter of 1990.
[5] According to the company, only the premium grade has passed the BMW
"unlimited milage" test, but the regular and midgrad fuels contain the
identical deturgent package.
[6] According to the company, Sunoco Ultra, a super-premium grade, passed
BMW "unlimited milage" test; Sunoco Super has not been tested. According
to the company, in other Sunoco blends, the lower the octane, the less the
protection.
* The gist of the BMW test described in the article is to take a new or
clean engine, dissassemble it and weigh the intake valves. Reassemble the
engine, run it on a test track in a 10,000 mile simulation of typical
driving, tear the engine down and re-weigh the intake valves. The
"unlimited milage" rating goes to gasolines which accumulate deposits
averageing less than 100 milligrams per valve or 50,000 miles in which the
average weight gain is more than 100 milligrams but less than 250 milligrams.
==============================
Section 11.2: What is oxygenated gas?..and why?
A: by David Draper: ddraper@domain.elided: edited)
Let me preface my comments by saying that there is an excellent article on
Oxygenated gas in the February 21, 1994 issue of AutoWeek magazine.
It goes into a fair amount of detail on oxy gas and the history behind
it. It also tells the contents of oxy gas for several of the big oil
companies.
There are currently 39 regions required to use oxy gas. It is unclear
to me if the pump must specifically say the gas is oxy gas but it must
say if the gas has any type of alcohol mixture in it (oxy gas).
Look on the pump and see if the gas either of the following in it:
ethanol/ETBE , methanol/MTBE
If either is present chances are it is oxy gas.
The maximum percetage currently allowed is 10% but ther has been talk
of raising the limit to 20%.
The article in AutoWeek mentions all kinds of potential and actual problems
that can be attributed to oxy gas. Some of them are hard starting,
stalling, hesitation, incresed instances of vapor lock and corrosion of
older engine parts. They also mention that gas mileage is decreased.
<<<<< (by John Auer: jaa@domain.elided)
Thanks to Harry Sidhu and Edward Bernard for their replies. The
concensus seems to be:
1. Oxygenatated fuel is mandated by the EPA in states where
pollution is a problem. Smog dissipates less quickly during
winter months, and the emission systems operate less effectively
as well, due to the increased warmup times. Oxygenated fuels
produce less emissions, helping the problem.
2. Some gasoline suppliers will deliver gas to "regions", not
"states" where the EPA has directed them to use such fuels,
to make shipping easier.
3. Oxygenated fuels can cause rough idle and hesitation problems
because of their chemical nature; this, of course, isn't news
to those of you using them...
<<<<< (by John De Armond: jgd@domain.elided: edited)
It is not marked on the pump but the slightly sweet, vaguely ether-like
odor of MTBE is distinctive once you've smelled it once. If your
gas smells like something other than gasoline, it probably contains
MTBE.
MTBE-laced gas provides less mileage than unadulterated gasoline
for the same reason any other oxygenate such as methanol or nitromethane
does - it carries some oxygen within its structure and that oxygen
displaces a combustable atom in the molecule. If no changes are
made to your engine, you will likely experience a lean-related
loss of power. However, if you're willing to retune the engine,
you will recognize a bit more power just as you would by adding
a few percentage points of nitro. Of course, you mileage will
get even worse. In effect, EPA is using a byproduct effect of
hotrod fuel to (allegedly) achieve their goals.
==============================
Section 11.3: What are the various ratings used for octane?
A: (by John Dempsey: johnde@domain.elided)
AKI: Anti Knock Index- This is the average of both the Research
and Motor Methods. It is also what you ussually see at the
pumps.
RON: Research Octane Number- Also known as ROM (Research Motor
Method). This is a real world number that is derived by
running a single cylinder engine on a fuel sample. The
timing is advanced until it pings. This advance is then
converted to a number.
MM: Motor Method- Using the same engine as above, the same
fuel sample is subjected to increased ignition timing.
But this time, something resembling reality is used in
in determining the number. Load, valve timing, ect. are
changed while the sample is being tested. This results
in a lower number than RON (the RON test is done at NO
LOAD). When you see a single, high number representing
octane, it is usually RON (like the old days of 100 octane).
Octane: This is an organic, hydrogen-carbon structure (a ring of 8).
Its' contribution to all this is that it was designated to
have a value of 100 (with Heptane having a value of 0) back
in the days when they were trying to rate and standardize
fuels.
Hence the scale became known as the Ocatane scale, and much
confusion on subject has followed. There is really not much
magic to all this. The idea was that a fuel with a rating
of 92 could be composed of 92% Octane, and 8% Heptane.
> If I'm not mistaken, "Octane" refers to the average of AKI and RON.
Pretty close. As you can see above, AKI = (RON + MOTOR)/2. Which of
course is the average of the two methods. With the advent of unleaded
gas, the name Octane was replaced with the term AKI. The idea was to
create less confusion, and give more meaning to the measurement.
> AKI and RON are two different rating schemes to measure the octane
It can also be seen above that the two methods of measurement are RON
and MOTOR methods. Remember, the idea of measuring the "Ocatane" of a
fuel was to see how much equivalent Ocatane it contained. If it measured
a 92 on the scale, that meant you could build an identical fuel using
92% Ocatane molecules, and 8% Heptane molecules. Of course, this or-
iginal idea of Ocatane measurement loses some its meaning when you go
above 100.
> of the fuel. Seems to me there's disagreement on which to use, so
> fuel manufacturers measure both, average them and call it "Ocatane",
Of the two methods, one is theoretical (RON) and the other closer to
actual conditions that might be encountered (MOTOR). I don't know if
that means there is a disagreement, just that they thought this method
was a fair and reliable way to measure.
> which is the number printed on the pump. (Octane, that is -- my terminal
Yep. This is the Octane, or now known as AKI, of the fuel. Just pay close
attention to what your manual specifies to use, and in what terms it gives
it in. I've seen some that say to use 92 RON, which is much different than
the number that you see on the pump these days. It is ussualy much higher.
> If you go by the manual, (89+95)/2 = 92, so 93 is fine
True.
<<<<< (by John Dempsey: johnde@domain.elided)
> I was wondering if you could explain to me why there is less energy in higher
> octane (a.k.a AKI) gas.
The above statment is indeed true, there is less energy (BTU's per pound)
in higher octane fuels than in lower octane fuels. Higher octane fuels
(like octane itself) have a benzene type of structure (ring structure),
while lower octane fuels have a parafine type of structure (linear chain
structure). Now as too why this difference in structure has a bearing on
energy content, I believe this is due to the differences in the bonds that
hold the individual atoms together. There is just not as much energy stored
in the ring structures. So when the molecule is oxidized, its energy state
drop is less than in a lower octane molecule.
The idea to remember here is that all matter seeks its lowest energy state.
The lower the energy state, the more stable it is. Also, if an atom has an
oportunity to reduce its energy state, it will indeed take it (like in the
combustion chamber of your engine). So a some what gaurded statement to
make is that as the stability increases (high octane), you give up some energy
content. This is indeed a simplified explanation.
Now the other question (if I can properly read between the lines), is if it
is indeed possible to produce a fuel with a high AKI rating, and the energy
content of a lower octane fuel. Yes and no. There is a range of energy
content around any particular AKI rating, but there are limits. This range
can be increased/decreased with the use of additives, construction, and
blending. All this is relative, and I'll leave TEL, nitro, ect. out of the equa-
tion. What you should remember is to use the fuel that just meets the re-
quirements of the engine- and that's it. This will give you the best
perform- ance, and at the lowest price. And for those that claim a peformance
increase when they switch to premium, well that is because you found a fuel
that better matches what the engine needs. Not because you just put in some
sort of wonder fuel (this is where anti-knock sensors confuse the issue).
It should also be noted that mixture quality, spark profile, and combustion
chamber design are just some of the factors that affect the octane requirement.
This would be another way to get the higher energy/lower octane fuels to work.
Ironically, this was the reason for the design of the stratified charge engine
in the earlier part of this century (so it could use the unheard of compression
ratio of 6 to 1 with the low octane fuels of the time).
> I have been told several times that not only will we not get anything out of
> the racing fuel (well over 103) found at race tracks, but according to some
> folks I spoke to at Dinan and other places (I have the chip in my car) we
> could even loose a bit of performance. Is this because (at least in part),
> that the fuel ignites so slowly at these very high levels (AKI) ??
Wow. Wise folks. The reason for the loss of performance is because of the
points made above. It has less energy per unit volume, you can't take ad-
vantage of it (unless you increase your compression ratio), so you are
wasting your time (and money). It does have cool factor though. About the best
per- formance increase you could hope for, is to convince your competitors of its
merits. They fork over huge sums of money to go faster (to of course keep
up with you). You go faster (because your not using it), they think it is be-
cause of the racing fuel, and it reinforces the illusion. Just don't try it
with anyone that reads the list. Oh, and keep it quiet.
==============================
Section 11.4: Should i use fuel additives?
A: (by Robert Cottingham: bwc@domain.elided)
My practice has been to always use premium gas from either Shell,
Mobil, Chevron, Exxon (in that order). I would never add any fuel
additives. My feeling is that fuel additives are at best a waste of
money unless you know what you are doing, and at worst can cause
problems.
My one exception to this rule is to add Techron when pinging starts to
occur. Pinging can damage the engine. Techron is the best product
for cleaning the injectors which is what usually causes pinging in BMW
fuel injected engines. In fact Techron was designed to address the
excessive pinging problems that occured in BMWs of the early 80s.
BMWs were used as the canonical engines for testing the effectiveness
of this product.
However, like all fuel additives, it has its downside which is that it
damages any rubber parts it comes in contact with, and it thins the
oil. Therefore one should only use it when absolutely necessary (ie
when pinging occurs), and then change the oil after the tank of gas to
which it has been added has been burned.
If your car is properly tuned, pinging should not occur more than
about once every 3000mi. It will occur alot less if you regularly
get your engine up to 4000rpm. I suggest once/week at least get
the car up to 4000 for at least 5mins (on non-e cars any way. I
dont have enough experience with e cars to speak for these, although
the pinging problem was worse on e cars in the early 80s.)
When you notice pinging, put a small bottle of Techron in at the next
fill up. Put the Techron in before putting the gas in to be sure that
it gets mixed well as the tank is being filled. You will need a stick
or something to hold the spring loaded flap in the filler neck open
while pouring in the Techron. Be careful not to spill the Techron on
any rubber parts of the car or even the paint. It will definitely
damage it.
If your car is pinging excessively and never had the injectors cleaned
it may be necessary to repeat this treatment, but once clean, and
assuming that it is driven the way a BMW was intended to be driven,
this should only have to be done infrequently. And you only want to
do it infrequently since its effect on the rubber parts in the fuel
system is not positive.
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