Tegger's latest oil consumption test

As regulars here will know, I keep very close tabs on my oil consumption,
trying to make the observation as close to a science as possible.

My latest test period (ended today) reveals consumption of 2,150 miles per
US quart.

Thus far in my record keeping:
1,500 mi/qt at 295,417 miles;
1,800 mi/qt at 296,494 miles;
2,500 mi/qt from 296,919 to 297,919;
2,150 mi/qt from 298,032 to 299,184.

It's been roughly 1,500-2,000 mi/qt for a few years now, but lately I've
decided to keep much more exacting records in an attempt at determining
consumption more precisely, and for spotting any trends or correlations. I
decided to do this after experiencing a few apparent episodes of alarmingly
high oil usage the summer before last.

I have discovered there is a direct relationship between how hard I drive
and the oil consumption. The higher the revs, the greater the throttle
openings used, the higher the oil consumption. This is, it has been
explained to me, a sign of a well-worn engine.

As a contrast, our Toyota Tercel has 90,000 miles on it. Normally it uses
no discernible oil between 2,500 mile oil changes. Last summer we passed
through the hills of Pennsylvania, all the way across PA to VA and DC. That
little engine therefore spent much of its time at full-throttle and high
revs, attempting not to lose speed on very long upward grades on the
Interstates. During that entire trip, the car used something around 1/8 or
1/4 of a quart in something like 1,000 miles. It would appear that even
new-ish engines with good rings are still prone to higher oil usage under
extended heavy load.

 

entirely to be expected. increasing load raises operating temperatures
and thus burn-off. use of a quality oil with a lower light fraction
will reduce burn-off rate as well.

 

I got your email and I see your point, but I've been using Mobil 1 for well
over a year now. If burn-off was a problem, I'd think I would have expected
to see immediate improvement in oil consumption within the first or second
oil change ( I change it every two months or so).

 

Curious as to whether it is all burn, no leak.

Frank

 

All burn.

The car doesn't leak a single drop.

 

That's pretty good. Seals been replaced? How often?

I've got a '90 and at 185K just starting to burn a very little, just
starting to leak a very little.

Got a 97 pushing 200K, leaks something awful. It is set for
replacement, gave it to my son 6 years ago, he wants a new Fit for his
daily commute.

Frank

 

All the original front seals were replaced at the car's second timing
belt change. We're going back a few years here. One of the cam seals was
weeping a bit, the other two were fine. I learned later that in the early
'90s there was a TSB out on my car having to do with leaky camshaft oil
seals.

The rear main seal was replaced at 255,000 miles when the clutch was
changed. The old seal was not leaking, amazingly enough.

The exhaust cam seal was replaced maybe five-seven years ago. This is
the big plug that is notorious for leaking.

The distributor O-ring is original and is not leaking.

I am convinced that very frequent oil changes stave off seal leakage. I
change my oil every two months or 2,500 miles. No matter what.

My mechanic explained to me that modern oil seals generally leak not
because they wear out or harden, but because they develop tiny surface
cracks. Acid etching and poor lubrication from old oil lead to the hairline
tears.

I have another timing belt change coming up this spring. All the seals are
getting replaced again, just in case.

Today's mileage: 299,406! Getting closer!

 

It would be interesting to see what effect all the variables have on
this. I have an '87 CRX automatic that has never had any seals
replaced other than for the timing belt change. 147K miles on the
car. If it uses even 1/8 of a quart between changes, which vary from
2000-3000 miles, I don't remember it. This with regular 10W-40 oil.
I've actually been a bit suspicious at the lack of oil usage, this
being a carbureted engine in a sometimes cold climate and all.

I have never had a Honda that used any oil. On the other hand, I have
never had a non-Honda (mostly GM products years ago) that DIDN'T use
at least half a quart between changes.

 

Tegger wrote:

That's quite an acomplishment for living in the rust belt...

JT

 

Keeping the /body/ alive is the real accomplishment!

 

I remember in the late 1960's when I was doing film work in the Marshall
Islands, cars would last anywhere from one to three years because of
rust. The worst were datsuns where the exhaust would fall off in three
months, the body would be virtually unusable after nine to ten months.

The trucks would last a little longer due to them having a frame. On
Majuro, the high school shop teacher totally removed the body/bed off
the frame and built a big plywood box with large open air portholes. He
made it last for about four or five years and was known as the island's
"plywood king."

JT

 

That's the sea air, obviously.

We had similar things happen up here, but that took eight-ten years or so.
Japanese cars back then (and Fiats!) were terrible for rust. It was not
uncommon for struts to poke through the strut towers and dent the hoods.

Speaking of sea air... If you're ever at Redondo Beach near LA, have a look
at some of the chain-link fencing surrounding the restrooms on the beach.
The side of the posts facing the ocean (windward side) are corroded to
nothing. The side of the posts away from the ocean (leeward side) still
have zinc on them. Very dramatic.

 

this was common to early-to-mid 1970s Hondas, too. I'm pretty sure the
struts were attached directly to the fenders. corrosion weakened the
fenders and the struts would pop thru. I remember helping a buddy
replace his fenders because his car was not included in a recall. I
think we added a piece to help reinforce the structure beneath the
engine. flimsy doesn't come close to describing those cars. got good
mpg, though.

 

I try to avoid California, too many crazies out there. That's where all
the nutty ideas originate.

I have problem enought trying to remain sane here...

<G>

JT

 

Actually, the strut towers were pretty rugged. But the engine cross
member could rot out. There was a recall for them as well as the fenders.

Later, the Gen 2 Civics (and probably other models) added a plastic
wheel well that protected the rear part of the fender that commonly
rotted away.

That's why I love old cars here in Central Texas. Old bolts 'n nuts turn
just as easy today as when they were put on the car during manufacture.

JT