From: gwu@tcsi.tcs.com (George Wu)
Subject: Frequently Asked Questions
Originator: gwu@nujoizey
Keywords: FAQ frequently asked questions
Organization: Teknekron Communications Systems, Inc.
Date: Tue, 7 Apr 1992 04:24:51 GMT



INDEX
======

	1)  Introduction
	2)  Tire Sizes
	3)  Synthetic Oils (Mobil-1, Golden Spectro, etc.)
	4)  Oil Additives (Slick-50)
	5)  Changing Your Timing Belt
	6)  Gasoline and Octane Ratings
	7)  Paint Scratches
	8)  Static Electricity Shocks
	9)  Auto Mailing Lists
	10) Dead Battery Problems
	11) Damp Weather Problems
	12) Used Car Repair Histories


1.  INTRODUCTION
================

     This is a list of answer to Frequently Asked Questions (FAQs) in
rec.autos.tech.  It's a general attempt to reduce the traffic in this group.
If you're receiving this message via email, it's probably because you recently
posted a question which is answered herein.

     Suggestions for additions or improvements to this list are welcome.  Send
them to gwu@tcs.com.  In general, I try to keep this list short and sweet.  I
also try to use only facts, not opinions.  If you disagree with something I've
stated here, feel free to drop me a line or begin a discussion in
rec.autos.tech.


2.  TIRES SIZES
===============

     The number is usually something like P225/60R14 95H.

     The P stands for passenger. Other code is LT for light truck.

     The 225 is the sidewall to sidewall dimension of the tire in mm. A wide
tire is good for dry road performance but use caution. You can change
speedometer readings, overall gear ratio and sometimes steering response in
adverse ways if you choose the wrong tire. For snow, a narrow tire is usually
the best choice.

     The 60 refers to the aspect ratio or the ratio of height to section width
as a percentage. i.e., 60 means that the height of the tire section is 60% of
the horizontal dimension. Usually the lower the aspect ratio, the better the
cornering ability, but the stiffer the ride.

   The R refers to the construction, in this case radial.

   The 14 is the diameter of the wheel in inches.

   The 95 is the Load Index which is a strange figure between 0 and 279 used to
indicate the load carrying capacity of the tire. I don't have a conversion for
all indices but 95 indicates 1323 lb at max inflation.  Note that this is a
per-tire figure.

   The H indicates the performance rating of the tire. These are as follows:

           Q - speeds up to 160 km/hr (100 mph)
           S - speeds up to 180 km/h (112 mph)
           T - speeds up to 190 km/h (118 mph)
           H - speeds up to 210 km/h (130 mph)
           V - speeds up to 240 km/h (150 mph)
           Z - speeds over 240 km/h (150+ mph)

   If there is a designation of M+S on the tire it meets the Rubber
Manufacturers' Association definition of a mud and snow tire.

   The above is a synopsis of an article from the Autoroute magazine put out by
Canadian Tire Corp.

[ Thanks to Peter Sheriff for the explanation. ]

     Now, most likely, you're reading this section because you want to install
larger tires, and possibly wheel rims, on your car for better handling.  The
most common change is known as a 1+ upgrade.  Essentially, you use a one inch
larger rim, and a one inch smaller tire.  Your rolling circumference is
unchanged, and hence, you needn't recalibrate your speedometer.  The above
tables and a little algebra will tell you just what size tire you want.  If
your tires are sufficiently tall (high aspect ratio, say 70 series and up),
even a 2+ upgrade might be feasible.

     Now, what about changing the rolling circumference?  If you really want to
improve your tire handling, you'll want to go with a tire/wheel combination
larger than the stock setup.  Get some advice from a tire dealer or the car
dealer.  Factors such as wheel offset and fender clearance are model dependent.
These folks have reference information on just what tire sizes will fit on
your car.  You can also get a rough idea by crawling under your car and
measuring the amount of clearance you current tires have.


3.  SYNTHETIC OILS
==================

     The advantage or disadvantage of synthetic oils over natural mineral
("dinosaur") oil is the topic of far too much bandwidth in rec.autos.tech.  If
you want a definitive answer, conduct a scientific survey.  Asking the net is
just a sure way to start another flame war, or be completely ignored if one has
just wound down.

     Most people concede synthetic oils last longer and withstand engine heat
better than dinosaur oils.  The question of debate is: how much longer, and is
it worth the extra cost?

     If you have a car still covered by the manufactuer's warranty, you *must*
change the oil at the specified maintenance intervals, regardless of the type
of oil you use.  It doesn't matter that a synthetic oil may last longer.
You're voiding your warranty otherwise.


4.  OIL ADDITIVES
=================

     The advantage of PTFE engine treatments is also the topic of much debate
in rec.autos.tech.  Supposedly, the PTFE (Teflon) coats one's engine and
provides additional lubrication.

     Again, asking the net will just generate a flame war.  You will find some
people who've tried it and bless it.  Others claim to have tried it without any
results.  Until independent research provides conclusive evidence, I won't
venture an opinion either way.


5.  CHANGING YOUR TIMING BELT
=============================

     Timing belts do need changing, but just how often depends upon the make
and model of your car.  Check your owner's manual or ask a mechanic you trust.
Especially in older Hondas and Toyotas, a broken timing belt means severe
engine damage because the valves get left in the path of the pistons.  I'm not
mechanically familiar with other brands of automobiles, or even many of the
above mentioned brands.  Check with an expert.  Typical replacement intervals
range from 60K to 75K miles, but this is definitely brand and model dependent.

     Because of the potential for severe engine damage, it is best to replace
a timing belt as scheduled, or if it shows any signs of damage.  Merely
eyeballing the belt while it is installed often will not detect cracks and
other wear normal in a belt as it approaches the end of it's useful life.  If
the manual says it's time to replace the belt, do it.


6.  GASOLINE AND OCTANE RATINGS
===============================

     As various consumer advocates will tell you, the vast majority of people
who purchase premium gasoline don't need to do so.  If your engine runs fine
and doesn't knock or ping, you can use normal 87 octane gas.  Your owner's
manual will tell you what octane your engine requires.

     Another common argument advocating the use of higher octane gas are the
detergent additives designed to keep fuel injectors clean.  If you car is fuel
injected, it is a good idea to use a brand of gasoline which includes a
detergent package at least occasionally.  This does *not* mean you need to
buy the higher priced premium fuel.  Many companies now use the same detergent
package in all their unleaded fuels.  From the April 1991 issue of Consumer
Reports, here's a list of the various brands of gasoline which pass BMW's fuel
injector test:

Legend:
-------
(A X means the fuel passes the test)
(A - means not pass)
(A blank means the company does not sell this kind of gasoline)

Brand                Regular  Midgrade   Premium     Comments
-----                -------  --------   -------     --------
Amoco			X	  X         X	  
Arco			X				A
Atlantic		X	  X	    X
BP			-	  -	    X		B
Chevron			X	  X	    X
Citgo			-	  - 	    X
Clark			-	  -         X		D
Conoco		        X         -         X
Diamond-Shamrock	X	  X	    X		E
Exxon			X	  X	    X
Fina			X	  X	    X
Getty			-         -	    X
Gulf			X	  X	    X		F
Hess			X	  X	    X   
Kerr-McGee		X	  X	    X
Marathon	        X	  X	    X
Mobil			X	  X	    X
Philips 66	        X	  X	    X		G
Shell			X	  X	    X
Sunoco			X	  X         X
Texaco			X	  X 	    X
Total			-         -         -		H
Ultramax/Beacon		-		    -     	C
Unocal			-	  -	    -		I


Key to comments
---------------
A - Co. sells EC-1 "emissions-controlled" premium in Calif., a fuel that 
    passes the test.

B - "Jobber-supplied" stations in Northest, in Pa. West of Johnstown, and in 
    Mich. sell premium fuel that does not pass BMW test; premium sold at other
    stations passes.

C - Co. says it expects regular and premium grades to pass BMW test by mid-1991

D - Co. says it will submit regular and midgrade fuel for BMW qualification
    this spring.

E - Co. sells RG-87 "environmentally formulated" gasoline, which passes BMW 
    test, in Denver.

F - As of Feb. 1, only station with "Advent 21" advertising sold fuel that 
    passes BMW test.  Co. says all stations will sell fuel that passes by the
    end of March.

G - Co. says fuel that passes BMW test will be available at all outlets by the
    end of Feb.

H - Co. says only stations with "TC490" advertising sell fuel that passes BMW
    test.

I - Co. says only stations west of the Rocky Mountains sell fuel that passes
    BMW test.

J - Co. says only stations with "Power Max Formula 4" advertising sell fuel
    that passes BMW test.


7.  PAINT SCRATCHES
===================

     There are basically two types of scratches: completely through the paint,
and not completely through the paint.  If you have a scratch or chip completely
through the paint and down to primer and/or metal, the only solution is the
obvious one: repaint the area.  For really large scratches in an obvious area,
such as across the hood, you'll probably need to have a professional repaint
the entire piece.

     If you have just a small scratch, or a chip from a stone, touch-up paint
carefully applied may hide the problem.  The idea is to apply the paint
exactly in the scratch, and only in the scratch.  Many people recommend using
a toothpick rather than the little brushes which usually come with touch-up
paint.  Before you try touchup paint in an obvious area, in fact, anytime you
open a new bottle, try the paint out in an inconspicuous area, perhaps
underneath the inside of a door.

     Finally, for scratches which do not penetrate through to the primer, you
are pretty much without recourse with today's modern clearcoat finishes.  In
the old days, careful use of rubbing compound could be used to polish the area,
in effect, buffing the scratched paint off to expose a new layer of paint.
However, clearcoat finishes are too thin to withstand such treatment.


8.  STATIC ELECTRICITY SHOCKS
=============================

     The shock some people experience when exiting a car is not a problem with
the electrical system.  It's simply static electricity, the same you generate
by rubbing your feet against a carpet.  The solution is pretty simple: hold
onto a grounded metal surface while exiting the car.  Part of the door frame is
as good a place as any.


9.  AUTO MAILING LISTS
======================

     Below are the mailing addresses for *SUBMISSIONS* to the various auto
related mailing lists.  In order to *SUBSCRIBE*, add "-request" to the end of
the list name (ie. not a machine name).  For example, to receive messages
concerning BMWs, send your email address to bmw-request@cma.com .

	autox@hoosier.utah.edu
	bmw@cma.com
	british-cars@hoosier.utah.edu
	f-body@boogie.ebay.sun.com
	INFO-HONDA@cs.ucla.edu
	italian-cars@cma.com
	mazda-list@ms.uky.edu
	miata@jhunix.hcf.jhu.edu
	mustangs@hpda.cup.hp.com
	porschephiles@karazm.math.uh.edu
	quattro@aries.East.Sun.COM
	rally@rally.team.net
	rx7club@cbjjn.att.com
	saab@dartmouth.edu
	school@cma.com
	vettes@cimage.com
	volvo-net@me.rochester.edu
	wheeltowheel@abingdon.sun.com
	z-car@dixie.com


10.  DEAD BATTERY PROBLEMS
==========================

     If your battery is having problems, in roughly the order given, try the
following steps:

	1) Clean the battery terminals and top of the battery, and check that
	   the cables are solidly connected;

	2) If your battery isn't of the sealed (no maintenance) sort, top off
	   the battery with distilled water;

	3) Verify the alternator and voltage regulator are both functioning
	   properly.  (Details?)

     After each of the above stages, recharge you battery and hope it holds the
charge over the next few days.  You may wish to combine steps one and two.  It
is also worthwhile to verify that none of your accessories (especially trunk
and glove compartment lights) are on all the time.

     At no time should you disconnect the battery while the car is running!
While useful in the old days, today's modern cars have electronic components
which are very sensitive to voltage fluctuations.  The battery normally serves
as a capacitor to smooth out the voltage generated by the alternator.


11.  DAMP WEATHER PROBLEMS
==========================

     Rough running or hard starting during damp or rainy weather are frequently
just bad spark plug wires.  Over time, the insulation of these wires breaks
down.  Moisture accumulated on these wires shorts out the sparking current.

     The solution to the problem is simple: replace your ignition wires.  This
job is relatively simple, and is usually included in shop tuneups.  A quick
temporary fix is to dry off the wires, possibly spraying them with one of the
water repellent products sold for this purpose.  However, the insulation isn't
going to get any better, so you'll eventually need to replace them.


12.  USED CAR REPAIR HISTORIES
==============================

     A good place to check for repair histories is Consumer Reports.  The
annual automotive issue contains, among other information, the frequency of
repairs of cars sold in the United States.  They even breakdown the information
by subsystem.  For instance, fromm the latest issue, I can tell my '89 Toyota
Celica has a far better than average likelihood of needing major repair work
done, with one exception: the exhaust system.  The exhaust system for this
particular car appears to be quite unreliable, as it receives the worst
possible rating.

     So, if you just want a general idea of how a particular make and model are
holding up, save the net some traffic and check out Consumer Reports.  We, the
readers of rec.autos.tech, are of course, perfectly happy to flame . . . errr,
provide additional feedback and personal anecdotes concerning the vehicles we
own and maintain.

-- 
----
George J Wu, Software Engineer        : gwu@tcs.com or uunet!tcs!gwu
Teknekron Communications Systems, Inc.: (510) 649-3700
2121 Allston Way, Berkeley, CA, 94704 : Quit reading news.  Get back to work.