Oil Consumption Update (April 2001 update)
Kirk Kohnen
I have a manual '97 SL2 that I bought new. I have been running nothing
but synthetic oil in it (almost exclusively Mobil 1 5w30. A change or 2
using Chevron Supreme full synthetic because it was cheap - $2.50 per
quart on clearance).
My commute is about 65 miles round trip, mostly on So Cal freeways (and
a little surface street driving). (updated June 22 - actually measured
it)
If you want to see previous stuff I've posted regarding this, fire up
dejanews (er, Google - Dejanews was bought out) and look for yourself.
Using a few of the exact mileages listed below as search keys will find
my previous posts for you.
Anyway, here are the raw consumption numbers:
35966 to 39027 miles consumed 30 oz of oil.
39027 to 42088 miles consumed 32 oz of oil.
42088 to 44822 miles consumed 26 oz of oil.
44822 to 47626 miles consumed 35.5 oz of oil.
47626 to 50613 miles consumed 35 oz of oil.
50613 to 53613 miles consumed 32 oz of oil.
53613 to 56674 miles consumed 38 oz of oil.
56674 to 59752 miles consumed 48 oz of oil.
59752 to 62764 miles consumed 44 oz of oil.
62764 to 65578 miles consumed 44 oz of oil.
65578 to 68582 miles consumed 52 oz of oil.
68582 to 71584 miles consumed 56 oz of oil.
I am modeling oil consumption as a simple linear function of the miles:
Ounces of oil per mile = A + B x Odometer Reading
(for those of you who have been following along in the news group
regarding my oil consumption, this is a slight change from the way that
I have been doing the analysis in the past. It permits me to account
for the slight deviation from exact 3,000 mile change intervals and get
a relatively accurate trend line).
The values of A and B that best fit the measured data are:
A = -0.000994393 ounces per mile (Aware that it's negative - that's how
curve fitting goes)
B = 2.6527E-07 ounces per mile^2
Projecting this data out, at about 64,100 miles (64,064 for the anal), I
started consuming 1.5 quarts per 3,000 miles, or 2,000 miles per quart.
This is the point at which Saturn declares that the oil consumption is
excessive.
Editorialization on:
If my numbers (using synthetic oil) are similar to numbers that one
would get with non-synthetic oil, I can see the business model for
Saturn not addressing the oil consumption issue. My engine started
burning excessive amounts of oil (according to Saturn) at about 64,100
miles. I believe that modern engines can, should and do burn much less
oil than this. But, it's hard to stand up and say that an engine that
burns 1 quart every 2,000 miles at 64,100 miles is still in some sort of
manufacturer's warranty - unless of course you spent the big bucks to
get the extended manufacturer's warranty.
Given that I have an engine which has received EXCELLENT care, I think
that starting to consume oil at the rate that its manufacturer declares
excessive at 64,100 miles indicates that my engine has a problem.
I will feed it oil as it needs, but it's clear to me that my Saturn SL2
engine has developed a drinking problem.
Editorialization off:
Before any of you flame me, take a look at the posings that I've made in
this group. Then, if you want, flame away. I think a key point here is
that I'm posting actual data regarding oil consumption. Please remember
that this is a single data point.
Please let me know what you guys think. Posting here or sending me an
e-mail works - either way. And, Saturn, if you're reading this feel
free to contact me - I can give you more details on what I've done if
you're interested.
Oh, and let me save you the trouble: Yes, I'm blissfully aware that I
have no life.
Vincent Valencio
representative or saturns CEO and ask the question straight out "why
do saturns burn an unusual amount of oil?" I could see it now, that
the CEO would reply stating: "all engines burn some amount oil
::shaking hands around to assert himself/herself:: the saturn just
happens to burn a little more. There could be many MANY reasons for
oil consumption:: Then the interviewer would ask: "But what would
explain the fact that these engines burn oil beyond saturns own
standards?"
::sigh:: whatever the reason I just wish saturn would get their act
together with this oil burning problem. It's ridiculous, and maybe
saturn has already addressed these problems. Too soon to tell. Can
any owners of the new 01' Saturns comment on their own oil
consumption? Please tell, I'd even pay substantial amounts of $$$ if
you make those detailed oil records for the newsgroup just like the
way Kirk Kohenen did his.
-Vincent
Kirk Kohnen <kkoohh...@attglobal.net> wrote in message news:<3B33815D...@attglobal.net>...