<mahadragon@gmail.com> wrote
about his/her 2001 Civic LX

Per your subsequent post, I see I just lost a bet. I googled
and saw some sites saying Honda started specifying 5W-20 (a
lower viscosity oil than 5W-30, of course) in 2001 so that
the company could report hire fuel mileage to the federal
government. See for example
http://www.synthetic-oil-tech.com/d.cgi/1102880/articles/ford5w20.htm

Right. For younger cars, synthetic is definitely more
economical. I count your 2001 as "younger."

Unless the car is /mostly/ driven under any of the severe
conditions listed below, this oil change frequency is
excessive. Severe Conditions (from the American Honda site:
--Trips of less than 5 miles (less than 10 in freezing
weather)
--Extremely hot weather (over 90 degrees F)
--Extensive idling or stop-and-go driving
--Trailer towing, car-top carrier, or mountain driving
--Muddy, dusty, or de-iced roads

(You are in the U.S., aren't you?)

The 3k miles/3 months frequency is a tactic by Honda
dealers, Jiffy Lube, et al. to sell more service. It's a
funny tactic, because Honda itself specifies 10k miles/one
year for your 2001 Civic.

Do you have an owner's manual? It should state the 10k
miles/one year interval above in its maintenance schedule.

I also think the 1996 study Consumer Reports did on this
reinforces how ridiculous it is to change the oil ever 3k
miles. See the article at
http://www.xs11.com/stories/croil96.htm

As for synthetic, this is much discussed here. A few reports
exist of minor oil leaks resulting from switching older cars
with high mileage to synthetic. But the data is really
scarce. For your 2001 Civic, I think you'd be fine switching
to synthetic. But that's only my opinion.

I have a 178k miles 91 Civic LX. I won't switch it to
synthetic, because synthetic is just a tad too much risk for
my budget if a serious oil leak does occur. Also, I change
my own oil and don't mind changing it more often than what
would be required with synthetic. It gets me under the car
inspecting the CV boots etc.

Synthetic vs. conventional oil is much discussed here. You
can search the newsgroup archives for more opinions. Or
google. :-)

I appreciate the citation and understand (and agree with)
your point, but I am not wild about the line at the link
below that says, "... the heavier the oil, the less it
lubricates." I see the author qualifies this subsequently.
In which case the line I quote above is "just" bad writing,
albeit writing that can mislead.

The extent of lubrication will be a function of temperature,
among other things, as you know. In very hot temperatures, a
heavier oil will lubricate better than a lighter one yada.
Basic stuff.

My viscosity guide chart in my 91 Civic Chilton's manual
shows, generally, higher weight oils to be applicable to
ahigher temperature range than lower weight oils. That also
suggests to me that engine wear is less of a concern with
higher weights and lower temperatures than loss of fuel
economy. That is, engine wear is likely worse with heavier
weights and lower temperatures, but it's not as bad as
engine wear with lighter weights and higher temperatures.

"TeGGeR® wrote:> You can use 5W-30 instead of 5W-20, but don't use
10W-40."

I used the 10W-40. Is that bad?

Steven

Engine oils are graded by those "weight" numbers. The number is calculated
from the results of tests that are appiled to engine oils to determine
their thickness, or "viscosity". The smaller the number, the lighter the
oil. The higher the number, the heavier the oil.

A "straight-weight", like the 30-weight that's still common in lawnmowers,
has only one viscosity rating, the "30" part. It gets very thin and watery
at high temperatures.

If you don't want it to get thin and watery when hot, but to stay more like
it was when cold, then you have to play with the oil's structure and
additives to make it stay more-or-less the same within a certain
temperature range. That's where "multigrade" comes in, and the oils are
described using two numbers, such as 10W-30. The first one is always
succeeded by a "W". I think this means Winter.

GEAR oils derive their ratings via similar tests, but those tests are
carried out at lower operating temperatures. Thus their numbers are higher
than engine oils for oils of identical viscosities. 30wt engine oil is
about equivalent in pour-ability to 75wt gear oil.

He's right. Actually, even a 5W is fine. 5W helps ensure the oil starts
circulating slightly faster than it would if it were 10W.

Some synthetics cover an even wider temperature range then regular mineral
oils, such as 0W-40.