Oil consumption observation 2012 Acura TL 3.7L

[MajorCavalry]

I own a 2012 TL SH AWD with 45K miles. My normal driving pattern is a 10-15 mile commute to my offices 5 days per week with many shorter drives on the weekend. The car has consistently used one quart of oil per 4K miles. The oil usage is linear from the time I change the oil. One quarter of a quart per thousand miles no matter how far along in the oil change I have traveled. It does not change in the heat of summer or the frigid temps in a New England winter. I have used various 5W-20 synthetic oils and have found no difference in consumption. This is not a complaint session for me. Just means an additional quart between oil changes.

I have noticed that if I use the car for an extended drive, the oil consumption drops to zero, zip, nada. Last year I drove to Myrtle Beach SC which is about a 900 mile drive. Outside temp ranged from 95-100. Speeds of 75-80 mph with only bathroom and refueling breaks. I checked the oil prior to leaving and it was exactly on the full mark after sitting overnight. Did some local driving down there to restaurants but not much. Returned home under the same conditions. When rechecked at home after sitting overnight, the oil level was exactly on the full mark. 1800 miles with not a drop of oil usage.

This year I did a drive to Cleveland for a family event. Ambient temp was 80. Speeds were 65-70. 1200 miles round trip and had the same result. Not a single drop of oil use!

Not sure conclusions can be drawn from this limited sample, but perhaps the oil usage occurs when the engine is cold and warming up. If so what might be causing it?

 

[Hokiefyd]

Originally Posted By: MajorCavalry
This is not complaint session for me. Just means an additional quart between oil changes.


I wouldn't complain about it, either. One quart in 4,000 miles is more than some engines use, and certainly less than some other engines use. Using *some* oil can be beneficial in the sense that you know that your upper cylinder walls are WELL lubricated. Cadillac Northstar engines are generally well-known for consuming oil. But many engines torn down after a few hundred thousand miles still showed the original honing marks on the cylinder walls.

Modern cylinder walls seem to be more aggressively hatched than they used to be, promoting excellent upper cylinder lubrication. The benefit to this is you don't see the ring ridge wear on modern engines that you used to have after 80-100k miles on older engines. The drawback, of course, is increased oil consumption. It's one of those "no free lunch" things.

You also will get some variation from engine to engine as tooling and equipment changes. Depending on how the cylinder liners are produced, you may have hone stone or other equipment changes throughout a production run. So an engine that comes down the line after a tooling change might have more aggressive cross hatching than an engine that came through right before a tooling change.

Neither of our engines consume a measurable amount of oil; I'd sort of rather that they DID. I wouldn't mind just a LITTLE bit of consumption, knowing that if the engine's using SOME oil, everything in the cylinder stays nice and slick.

 

[Chris142]

my pickup does thr same.a qt in 600 miles in town but none screaming down the hwy.

 

[MajorCavalry]

Originally Posted By: Hokiefyd
Originally Posted By: MajorCavalry
This is not complaint session for me. Just means an additional quart between oil changes.



You also will get some variation from engine to engine as tooling and equipment changes. Depending on how the cylinder liners are produced, you may have hone stone or other equipment changes throughout a production run....


Interesting thought. One thing about this engine is that it does not have honed cylinder liners in the traditional sense. The cylinders have a layer of hypereutectic silicon aluminum alloy. The cylinders are "machined" with an abrasive designed to remove some of the aluminum while leaving the silicon crystals to support the rings. Similar technology was used in the Chevy Vega (not very well), older Mercedes V8 engines, Audi (not so oil tight), and BMW (but that was Nikasil which is slightly different). Only the 3.5 L Acura engine has honed cast iron cylinder liners.

 

[ARCOgraphite]

older Porsche v8 in 928s4 also used etched back Si unlined Al Reynolds alloy block too

This sounds like it could be warm-up blowby during wide clearance and gummed rings due to round town short tripping ... Or Not!

 

[Hokiefyd]

Originally Posted By: MajorCavalry
Interesting thought. One thing about this engine is that it does not have honed cylinder liners in the traditional sense. The cylinders have a layer of hypereutectic silicon aluminum alloy. The cylinders are "machined" with an abrasive designed to remove some of the aluminum while leaving the silicon crystals to support the rings. Similar technology was used in the Chevy Vega (not very well), older Mercedes V8 engines, Audi (not so oil tight), and BMW (but that was Nikasil which is slightly different). Only the 3.5 L Acura engine has honed cast iron cylinder liners.


Interesting, and thanks for that clarification.

It still sounds like there's potential for manufacturing variation (there always is, right?). If an abrasive is used to remove some of the aluminum, leaving silicon crystals behind, I'm almost positive that the abrasive is consumed during the production process, and there will be some engines manufactured with "new" abrasive material on the tools and some engines manufactured with "old" abrasive material on the tools. It could be that fresh abrasive removes more aluminum, leaving a "rockier" surface (which might retain more oil), and used abrasive would leave a smoother surface, which wouldn't retain as much oil.

Of course, then again, we could find that Acura's use of this non-traditional silicon treatment could be a big flop, as it was determined with BMW's Nikasil and others, and you got lucky with and engine that drinks "only" 1 qt/4,000 miles.

I suspect the former is more likely than the latter, but only time will tell I guess.

I probably does stand to reason that a fully warmed-up engine running at a pretty much constant speed would consume less oil than one subject to more cold starts.

 

[kjbock]

Originally Posted By: MajorCavalry
Originally Posted By: Hokiefyd
Originally Posted By: MajorCavalry
This is not complaint session for me. Just means an additional quart between oil changes.



You also will get some variation from engine to engine as tooling and equipment changes. Depending on how the cylinder liners are produced, you may have hone stone or other equipment changes throughout a production run....


Interesting thought. One thing about this engine is that it does not have honed cylinder liners in the traditional sense. The cylinders have a layer of hypereutectic silicon aluminum alloy. The cylinders are "machined" with an abrasive designed to remove some of the aluminum while leaving the silicon crystals to support the rings. Similar technology was used in the Chevy Vega (not very well), older Mercedes V8 engines, Audi (not so oil tight), and BMW (but that was Nikasil which is slightly different). Only the 3.5 L Acura engine has honed cast iron cylinder liners.


I believe the BMW N52 engine uses Alusil liners, instead of Nikasil. Don't think I've heard of people having oil consumption problems with the N52, though I've not done a lot of research either.

 

[k24a4]

May I ask if you are the original owner, and if so, how you broke in the engine?

 

[MajorCavalry]

Originally Posted By: k24a4
May I ask if you are the original owner, and if so, how you broke in the engine?


I would warm the engine up gently. My normal driving takes me over a "mountain" (in CT we use that term loosely) which has a several mile 5% -6% incline. RPM to reach the peak approx 3K. Coming down the other side is very little gas, lots of "foot off the gas pedal" with high engine vacuum. This is two days per week. Remainder of my driving has many stop lights and stop signs with some cruising and some highway.

And yes, I am the original owner.

 

[4wheeldog]

I have a motorcycle that has the same pattern of oil consumption. My conclusion is that it consumes what oil it consumes on startup. More startups, more consumption. Ride all day, for days on end, no consumption.

 

[Kool1]

Accelerating, especially under high rpm, uses oil in most vehicles. Guys who track their cars typically say they burn oil while tracking the car but don't use any oil when daily driving.

 

[OneEyeJack]

Any visible smoke? PCV valve okay? The dealer will tell you it's normal. I guess it's just manufacturing luck of the draw. I overhauled my 84 Civic in my driveway with help from the local machine shop for the stuff I could not do, I very carefully re-assembled everything and no matter the weather or how I drive it, it does not burn a drop of oil between 5k oil changes.

 

[MajorCavalry]

I do not actually think one quart per 4K miles is excessive consumption. I realize some vehicles will use none (fantastic) and some will use more (bummer) due to manufacturing variance.

 

[KrisZ]

It's interesting to note that OP's experience (consuming oil during short trips vs no consumption during highway runs) goes against some claims here that the only reason Toyota and others recommend thicker oil for high speed driving, is to reduce oil consumption.

 

[rjundi]

I have the very similar engine 07 MDX with 122k. It consumes around 1/2 quart every 7k-8k miles using 5w30 that my mechanic puts in. The Acura dealer oil change using likely proper 5w20 it consumed closer to 1 quart same OLM oci. Similar driving style.

 

[ARCOgraphite]

Going down that hill fully throttled on a semi warm engine will eat oil. You are whipping up oil with the crank going up and sucking in the pcv going down hill.
You could put an air/oil separator on the PCV inlet to see how much is crankcase "fog" being ingested and also keep the intake from being oil slimed.

 

[MajorCavalry]

Originally Posted By: rjundi
I have the very similar engine 07 MDX with 122k. It consumes around 1/2 quart every 7k-8k miles using 5w30 that my mechanic puts in. The Acura dealer oil change using likely proper 5w20 it consumed closer to 1 quart same OLM oci. Similar driving style.


I could be wrong but I think the 07 MDX has the 3.5L engine with cast iron cylinder sleeves. I did try one oil change of Mobil 1 5W-30 ESP (got a real good deal on it). No difference in oil usage.

 

[Vikas]

Is it true that the difference between 3.5 and 3.7 is what you described as "not traditional cylinder walls"? Does that account for the 0.2 liter difference?

 

[Greasymechtech]

Try 0w20's. Rings not sweeping cold thick oil too well.

PCV issue? Cheap enough to replace pcv valve to see what happens.

Install an oil catch can to see if the downhill vacuum is pulling oil mist.

Change air filter if it hasn't been changed.

 

[MajorCavalry]

Originally Posted By: Vikas
Is it true that the difference between 3.5 and 3.7 is what you described as "not traditional cylinder walls"? Does that account for the 0.2 liter difference?


There are definite differences between the two engines other than a small increase in displacement. This link provides a nice review of both these engines. Far better than I could articulate.

http://www.honda.com/newsandviews/article.aspx?id=5933-en