Tegger's real-world oil-consumption chart

[Tegger]

I have a 1991 Acura Integra with (currently) about 343,600 miles on it. At this mileage, it's sort of inevitable that oil usage is going to be a lot higher than it was when the engine had fewer miles on it.

After a scare a couple of years ago (the last time I posted here, I think), I decided to make a near-science of monitoring my oil consumption, so I could find out how much oil I was REALLY using.

The results of two-years of testing have led me to several conclusions:
1) ambient air temperatures make no difference in consumption, but age of oil might;
2) usage cycles up-and-down regularly, for no apparent reason;
3) it takes a long time and many test-cycles to determine a trend.

It does not seem to be possible to post a PDF to this site, so I'll post a link to the PDF on my own site instead.
85KB PDF chart of Tegger's oil usage

I did this chart for "summer" only, which covers from about mid-April to late-November, outside of which dates the winter tires go on, and mess up the method on account of their slightly larger diameter.

I've tried to be as consistent and as accurate as possible with my testing methods, but I think 17 cycles covering approximately 35,000 miles and 24 months is enough to detect the engine's actual consumption.

Hope this is of interest to some here.

--
Tegger

 

[d00df00d]

Interesting.

Have you been using the same oil the whole time?

 

[rjacket]

So you're losing a quart every 1700 or so miles and then changing the oil out at 3000 miles.

That means you'll have topped up 2 quarts by the time you change your oil? Right or do you just top up at 1500 miles with 1 quart?

Since you're topping up oil quite often, why not extend the intervals? With a decent filter, maybe you could just consider changing at 7500 miles, which would be after 3 to 4 tops ups. Your oil would be constantly replenished anyway.

 

[cchase]

You say "age of oil" might alter consumption. Are you referring to the mileage on the oil in the sump? As in, oil with lower miles may be consumed faster/slower than oil with more miles?

 

[JHZR2]

our integra used zero oil (not noticable on the dipstick) over 7500 mi intervals at 188k when we sold it due to rust. When did yours start to show consumption?

 

[Tegger]

Originally Posted By: d00df00d
Interesting.

Have you been using the same oil the whole time?



Yes. And the same make of oil filter.

--
Tegger

 

[Tegger]

Originally Posted By: rjacket
So you're losing a quart every 1700 or so miles and then changing the oil out at 3000 miles.

That means you'll have topped up 2 quarts by the time you change your oil? Right or do you just top up at 1500 miles with 1 quart?

Since you're topping up oil quite often, why not extend the intervals? With a decent filter, maybe you could just consider changing at 7500 miles, which would be after 3 to 4 tops ups. Your oil would be constantly replenished anyway.


After the first level check I top it back up. Then I top it back up after the second check. At each check-time it's down a bit more than a pint, depending.

I've considered increasing the change interval, but I'm too cautious to want to actually do it.

--
Tegger

 

[Tegger]

Originally Posted By: cchase
You say "age of oil" might alter consumption. Are you referring to the mileage on the oil in the sump? As in, oil with lower miles may be consumed faster/slower than oil with more miles?



Yes, the mileage on the oil in the sump. I don't know at this point if there are other factors at work here, of if in fact "aging" the oil causes it to somehow be consumed less by the engine. I'm convinced that my results are accurate, but I'm at a loss for explanations as to what I see.

--
Tegger

 

[Tegger]

Originally Posted By: JHZR2
our integra used zero oil (not noticable on the dipstick) over 7500 mi intervals at 188k when we sold it due to rust. When did yours start to show consumption?


I see my original posts are still on BITOG (do a search for my username).

I also see that I mentioned back on March 20th 2006 that I was getting about 2,200 mi/qt. This past winter (2009/2010) I got that exact same number. In both instances the winter tires were on the car. Since the snows are a slightly different size from the summer tires, they produce different numbers.

So, to answer your question, I started noticing the higher consumption at (very roughly) 250,000 miles. And it appears not to have changed at all in the ensuing ~100,000 miles. I'm not sure if these things are progressive, or if they go in steps, so the future is a question mark.

--
Tegger

 

[d00df00d]

Originally Posted By: Tegger
Originally Posted By: d00df00d
Interesting.

Have you been using the same oil the whole time?



Yes. And the same make of oil filter.

--
Tegger

Excellent. What oil?

 

[Tegger]

Originally Posted By: d00df00d
Originally Posted By: Tegger
Originally Posted By: d00df00d
Interesting.

Have you been using the same oil the whole time?



Yes. And the same make of oil filter.


Excellent. What oil?


Mobil 1 5w30, and a genuine-Honda oil filter with each change.

Since I mean this to be as accurate a test as possible, I wanted to avoid/eliminate as many variables as possible. That also meant that I was careful to make sure the gas tank was always at the exact same level (completely full), and that the car's cargo loading was always the same (empty) to ensure that the car's attitude was precisely the same at every check.

--
Tegger

 

[Tegger]

Originally Posted By: d00df00d
Originally Posted By: Tegger
Originally Posted By: d00df00d
Interesting.

Have you been using the same oil the whole time?



Yes. And the same make of oil filter.



Excellent. What oil?



My reply to you does not seem to have shown up. Plus I've obviously been stupid and posted this to the Diesel forum instead of the Gasoline forum. I have asked the moderators to move this thread.

The answer is: Mobil 1 with a genuine-Honda filter with each change. I wanted as few variables as possible, to make the numbers as accurate as possible.

--
Tegger

 

[tig1]

My sons 91 Ranger has 342K and the oil consumption(Mobil 1 10w30 with 10-14K OCI) is the same today as it was 18 years ago.1 qt. every 3500 miles.

 

[Tegger]

Originally Posted By: tig1
My sons 91 Ranger has 342K and the oil consumption(Mobil 1 10w30 with 10-14K OCI) is the same today as it was 18 years ago.1 qt. every 3500 miles.



Your son's Ranger is probably higher-geared than my Integra. Honda cheated with the 'Teg, giving it low gearing to make it seem fast. That low gearing results in a busy 4,000rpm at 80mph.

--
Tegger

 

[calvinnnnnnnnn]

switch to a 10w30 high mileage oil, you'll probably see less oil consumption.

i suggest maxlife full synthetic 10w30 or if you're a m1 fan Mobil 1 High Mileage 10w30.

btw, honda oem filters(A02) are made by fram(terrible quality control)

 

[Dave Hess]

Tegger,

you got a great website for Honda/Acura owners.

 

[tig1]

Originally Posted By: Tegger
Originally Posted By: tig1
My sons 91 Ranger has 342K and the oil consumption(Mobil 1 10w30 with 10-14K OCI) is the same today as it was 18 years ago.1 qt. every 3500 miles.



Your son's Ranger is probably higher-geared than my Integra. Honda cheated with the 'Teg, giving it low gearing to make it seem fast. That low gearing results in a busy 4,000rpm at 80mph.

--
Tegger


I gave the Ranger to my son when it had 190K, but as I remember at 70MPH it turned about 3100 RPM.

 

[Tegger]

Originally Posted By: calvinnnnnnnnn
switch to a 10w30 high mileage oil, you'll probably see less oil consumption.

i suggest maxlife full synthetic 10w30 or if you're a m1 fan Mobil 1 High Mileage 10w30.

btw, honda oem filters(A02) are made by fram(terrible quality control)


Before I started keeping precise records, I kept records that did not have the same degree of rigor to them. Those records are NOT included in the chart, but do encompass a few tests with 10w30 (one was Castrol's version of high-mileage oil). There was no apparent change in consumption. There was an ALARMING increase in consumption (~1,000 mi/qt) with my one-time use of Mobil 1 0W-40.

As for the FRAM-made OEM Honda filters, if they've been good enough for Honda Canada for 20+ years, they're good enough for me.

--
Tegger

 

[Tegger]

Originally Posted By: LT4 Vette
Tegger,

you got a great website for Honda/Acura owners.

Thanks. But it's badly in need of hours of updates and corrections.

--
Tegger

 

[Elle]

I think this study is very well-done. On another automotive forum, Tegger explained more about his methodology and changed the pdf file he linked in his first post to show more detail. My observation at this other forum was as follows:

I too would think that oil consumption would be pretty consistent over the 41k miles, given the same driver and same general driving habits. But taking into account errors in measurement, consumption perhaps is pretty consistent. For example, using the pdf file linked above, the reader can surmise that the average consumption was about 1660 miles per quart (mpq) with a range from 1500 to 1850 mpq, or +/- about 10%. Reading error for each measurement taken would maybe be around 0.04 quart ( = about one-half a gradation = about one-half mm on the calibration chart next to which you held the dipstick). Temperature effects might cause an error in reading of around +/- 0.03 quart (= .0005 per degree F * 20 degree F * 3 quarts). You monitored every 1k miles or so, so I gather you did two readings of the dipstick per data point. Each reading could be off by 0.07 quart. Hence any given data point might be off by around 2*(.04+.03) quart = 0.14 quart or around 10% error, consistent with what your readings were. Hence I would say the variation you found might be explained by the measurement error involved in doing readings. Hence the average number you found is useful.

I would say the DIY-er (who maybe is less careful than Tegger was in this study) interested in monitoring oil consumption should read variations of up to about 30% as likely mere measurement error and not actual changing oil consumption rate of his or her car.