response 1 of 25:

Jun 13 06:55 UTC 2002

The owner of the gas station may have been tampering with the oil. His refusal
to tell you who owned the place reinforces my suspicion.

When I lived in Farmington Hills, it was pretty well known that you shouldn't
buy gas at the Speedway station on 8 Mile, because the owner was constantly
getting in trouble for diluting his gasoline with water, very cheap alcohol
derivatives, or other liquid substances that didn't belong in gasoline. 

It was a rather vicious circle, because he'd get fined every time he was
caught, which would make him more inclined to tamper with the gas, so he could
make enough money to offset the fines. 

Without getting all "conspiracy theory" here, think about how most people use
oil when they buy it from a gas station. They usually pour it in to their car
before they drive away, and toss the empty container in to the trash. Does
it seem very unreasonable for an owner to fish the containers out of the trash
bag en route to the dumpster, fill the "expensive" containers with "cheap"
oil that probably costs him $0.65/qt. so he can sell it for $2.89 instead of
$1.89? And now since he's left with a bunch of empty "cheap" containers, he
could fill them with water, vegetable oil, etc. and sell them for $1.89. 

Seriously...consider it. You and I know "oil is oil", but not everyone else
does. Naturally, nobody would complain about the expensive oil, because they
wouldn't notice a difference. If anyone bought the cheap oil and complained,
how hard would it be for him to blame it on the fact that it's "cheap" oil,
and inherently inferior?

response 3 of 25:

Jun 13 09:31 UTC 2002

A sealed orifice has been my experience also.  There is nothing unusual,
improper or deceptive about selling engine oil that is below the standard set
by the car manufacturer.  The owners' manual always says what SAE
specifications you must have beyond the weight grade and it is the customer's
duty to read the oil label as one would check the ingredients on packaged
food.

You could have used the oil around the house.  Maybe in your lawn mower or
to top off your James Bond road oiler.

response 5 of 25:

Jun 13 14:41 UTC 2002

Ok, I used to live over by bru and if he is talking about the Amoco 
station that is over by US-23, I have to mention that that particular 
gas station has always been more expensive than any of the other nearby 
stations. I always figured it was because it was the only gas station 
at the Plymouth/Green road intersection and also because it is so close 
to the freeway. 

I have to wonder why Bruce feels it is necessarity to mention the 
ethnicity of the staff working at the gas station as if that has 
anything to do with the oil they were selling. 

response 7 of 25:

Jun 13 14:44 UTC 2002

No, it's the one on Main and William. It's right up from my office, so it's
handy when he needs gas after picking me up. 

response 9 of 25:

Jun 14 03:03 UTC 2002

I'm confused... what was it on the bottle that clued you in that this oil
wasn't up to what your car needed?

response 11 of 25:

Jun 14 08:26 UTC 2002

It's not necessarily true that oil has to have a "yellow" color - some
of the expensive synthetics are also close to clear.  However, "not
rated for engine use" is certainly not a good sign.  I suspect there's
more to what was on the label than what bru said - I've seen similar
stuff at Meijers.  The stuff at Meijers, at least, isn't so much "not
rated" as it's rated to a much older standard (SF instead of SJ or some
such), which is (I think) a 1960's motor oil standard.  It would not be
a good standard to use for modern engine oil.  Generally motor oils are
a superset of previous standards, so SJ motor oil is generally
preferable to SF motor oil, even for an engine originally designed with
SF oil in mind.  There are exceptions; many modern motorcycles, for
instance, have wet plate clutches where the clutch actually sits in the
motor oil.  The anti-friction oils have a bad effect on such clutches.
Unfortunately, the service grade isn't a good enough indication of
whether a given variety of oil has the bad anti-friction compounds.

response 13 of 25:

Jun 14 13:56 UTC 2002

Caveat emptor.  When you buy the cheapest thing on the market, you're an 
idiot if you don't inspect it/read the label/etcetera before purchase to 
insure that it meets your minimum requirements.  Everything you need to 
know about that oil is printed on the outside of the jug.  I've seen the 
stuff in the Amoco on State by I-94.

response 15 of 25:

Jun 14 21:32 UTC 2002

re: 12
I don't know about your luxury Fiat, but most American cars have the oil
requirements on the oil cap now.

response 17 of 25:

Jun 15 01:42 UTC 2002

Half the people I know lose the manual to anything they buy in the 1st 6
months.  Half of those that remain lose it when they sell it.  The
chances that a used car will have the original owner's manual are
actually pretty dim.  If the car is not too exotic, it should be
possible to order a replacement manual.

With many cars, the recommended oil is often a function of the expected
ambient temperature - heavier weight oils in summer, lighter weight oils
in winter.  I would not count on being able to read the resulting fine
print on any "recommended oil" sticker in the engine compartment after a
few years of road grime.  You are more likely to find a useful
recommendation for the automatic transmission, power steering, or
radiator fluid reservoirs, because those vary less.

Most modern engines take some form of multi-viscosity oil (such as
"10W-40"), rather than a straight viscosity oil ("30 weight").  This is
oil that is mixed so that it does not thin out as quickly at high
temperatures.  There may be several such oils that match your expected
operating temperature range.  Generally, all things being equal, an oil
with the smallest range (such as "20W-40") will be cheaper and last
longer than an oil with a wider range (as "10W-50").  Quick oil change
places don't always steer you towards such a choice - they tend to like
"one size fits all" solutions, such as the ever popular 10W-40, over
some more speciality oil such as 10W-30.  The owner's manual generally
doesn't contain such guidance.

response 19 of 25:

Jun 16 03:12 UTC 2002

I use 10W-30 because, well, it's a V-6.  That's what's recommended.

I was told 20W-50 is more of a racing lube, but yeah, it's been 
recommended to me when I had an aging car that has since given up 
(differental bearings wore out, and my mechanic friend didn't want to 
do it; not engine death)

response 21 of 25:

Jun 18 14:16 UTC 2002

Re #18: 20W-50 should be okay for summer use; I think the pumping point for
20W is about 15 degrees F.  (Below that it may be too thick to circulate
properly.) I used to run 20W-50 in my VW in the summer, and 10W-40
in the winter.  You'll notice an immediate improvement in oil pressure with
the thicker oil.  The problem is probably that the crankshaft bearings in
your car's engine are worn, and the increased clearances mean that the
thinner oil flows out of the bearings and into the oil pan faster than the
pump can pump more in.

If you decide to run 20W-50, keep in mind it's a bit hard to find sometimes. 
Most oil change places won't stock it, and not all stores will.  I usually
bought Castrol 20W-50 a few quarts at a time and carried it with me, but
then I was using a quart every 1000 miles, too.

If the car has any oil leaks at all, even a slow drip, don't even think
about putting synthetic in it.  It'll leak like a seive, and that stuff is
expensive.

Car makers have been steadily switching to lighter and lighter oils because
it helps them meet CAFE standards.  New Hondas now recommend 5W-20!

response 23 of 25:

Jun 19 12:45 UTC 2002

Re #22: I've heard that about 10W-40, too, but I'm not convinced.  It may
have been true at one time, though.  Isn't 20W-50 the same spread as 10W-40? 
I can't remember if the scales are linear or not.

What really scares me is that 0W-30 synthetic Mobil sells.  That stuff is
really thin, like water. ;)