"All engines burn some oil." Really?

[BLND1]

I have never once had to add oil (or noticed a significant drop in level) to my Tacoma's v6. In almost a decade of ownership I've had OCI's of 5k to 12k with no noticeable consumption.

I'm sure there is SOME. But it's not significant enough to really notice or pay attention to, and certainly not enough to warrant adding oil prior to a full change.

 

[talest]

I am thinking of switching to synthetic, let's see if my engine suddenly starts to use oil...

 

[Triple_Se7en]

Originally Posted by talest
I am thinking of switching to synthetic, let's see if my engine suddenly starts to use oil...

Engines can begin to consume oil at any time. Switching to a synthetic - or vice-versa, doesn't mean sudden consumption won't occur. Thousands of people switched to (example) Mobil-1 and began to consume oil. Sometimes the new consumption slowly stops after a couple of OCIs with (example) Mobil-1.

Also, consumption doesn;t mean your engine took a turn for the worse. There are numerous other factors on how synthetic benefit over conventional. Temperature extremes (+ or -) protection and longetivity are just two reasons. There's more.

 

[buster]

A lot of oil consumption in modern cars I feel is due to the ring type. All my Hondas used oil. Mazdas didn't conume any and I've had (3).

*What do most consider as oil consumption? For example, if you start off with the oil level at the top fill hole, and it moves down 1/2 the dipstick when you change it, do you consider that oil consumption? I wonder when people fill out the UOA sheets if they consider that zero oil consumption?

 

[john_pifer]

Originally Posted by 14Accent
I've had everything from oil guzzlers to oil vegan's. It just depended on the car. I've also owned 4 Northstar's, the only time those don't burn oil is when they're all out. My '98 Corolla was also a guzzler, a common 1ZZ-FE issue.

That being said, my current Impala burns no oil at 180k, although it's had either full-syn or HM it's whole life. My 225k mile Marauder with the 4.6 (another known oil burner) didn't use more than half a quart every 5k.

Low tension rings are a big part of the issue. The Subaru FB20 is a perfect example. Those things eat a steady diet of 0W20 like it's going out of style. I don't care what anyone says, that engine is an oil burner. Every single one of them.


I've never heard of the FB20. But I had a 2016 WRX with the FA20 DIT that didn't use much, if any. Only time I'd notice it dropping a few MM on the stick was if I'd taken the car out to the mountains and really flogged it at Deal's Gap/Cherohala Skyway, etc.

But I also used PPPP 10W-30 exclusively,which is one of the most stable, low-Noack oils on the market.

I also didn't baby it when it was new. It got driven hard from the get-go, which I believe is crucial to "setting" the rings, which prevents oil usage and ensures the engine meets its power potential.

 

[LeakySeals]

All the 4 cyls I've owned foreign or domestic have consumed some oil, require top off during a 5-6k OCI. Toyota and Nissan the biggest consumers. The only vehicle I've ever owned that consumes no oil is the 6.0 LQ9 Escalade in my signature. In disbelief last summer I took pics of the dip stick just after the oil change, at 3k, and at drain time which is +-6,500 or 0% on the OLM. No change. still full.

In addition to good maintenance practices, IMO the piston design is the biggest contributor to oil consumption. Toyota stubbornly designs pistons with tiny oil return holes that foul and clog over time. The 99-02 Toyota 1ZZ-FE and 02-09 2AZ-FE were well known for it. And once the piston oil return holes clog, the rings can no longer sweep away enough oil. The excess oil gets flashed during combustion, fouling the piston tops and rings. The rings get stuck, the consumption begins to increase dramatically. I thought things would be different when the 2.5 came along. Nope. My dads 2012 Carmy 2.5 consumed oil from day 1. The LQ9 has special flat top pistons for added compression. Not sure if that is why it consumes no oil. My guess is because the piston is designed for high performance it has better oil control. I belong to a forum of Escalade owners that have that engine, and all say the same thing. Its no fluke.

I have noticed increased consumption initially when changing brands. Perhaps the oil needs to set up on the surface of the cylinder walls, not sure. But after a few oil changes with the same brand, the cunsumption goes back down again.

 

[pschnahc]

All engines burn oil is a truism often used to deflect in conversations about problematic oil consumption when someone tries to excuse noticeable oil burning for whatever reason

 

[Doublehaul]

10k oci on 2 Toyota's with Mobil 1 0w40. No appreciable consumption

2TRFE, 1GRFE

 

[CR94]

Originally Posted by LeakySeals
... Toyota stubbornly designs pistons with tiny oil return holes that foul and clog over time. ... And once the piston oil return holes clog, the rings can no longer sweep away enough oil. The excess oil gets flashed during combustion, fouling the piston tops and rings. The rings get stuck, the consumption begins to increase dramatically. ...
That must explain why my 2ZR-FXE consumes amazingly little oil, so far. You're right, though, that some of these are much worse, even at lower mileage than I have. Toyota revised the pistons a couple of years later, supposedly to reduce the problem. How specifically they changed them would be interesting info.

 

[pschnahc]

Some engines don't even have piston oil holes at all and many of those engines don't characteristically consume oil. So if there wasn't another factor involved, I think those smaller oil holes shouldn't have been a problem. Those Toyota engines might have been perfectly fine if they have had used an API SN oil from the start. Diligent oil changers/synthetic users probably haven't suffered the issue as badly either.
I've heard the issue is thermal management, where Toyota on a few of their engines opted for elevated chamber temperatures for emissions purposes, increasing oil coking around the rings and indeed accelerating oil breakdown in the engine (sludgemonsters). In such case, it makes sense that increasing oil flow around the piston can help slow the coking problem but doubt that it's a permanent solution without other engine changes. On the plus side, a fantastic coincidence for owners of hard-on-oil engines of the past is that newer oil standards are seeing modern conventionals perform on par with HC synthetics of yore and have probably helped more than anything.

 

[john_pifer]

Originally Posted by Doublehaul
10k oci on 2 Toyota's with Mobil 1 0w40. No appreciable consumption

2TRFE, 1GRFE


Same. 2007 Tacoma V6 that now has 223K. Uses no measurable oil between 10K OCIs. I've done every oil change, and it's never had anything but some flavor of Mobil 1 5W-30 (and 10W-30 a few times) since its first oil change at 3000 miles.

 

[BAJA_05]

Funny I still see more older Toyota Camrys/Corollas 1993-2006 than ANY other car maker out there on the road racking up mile after mile!!!

 

[BLND1]

Originally Posted by john_pifer
Originally Posted by Doublehaul
10k oci on 2 Toyota's with Mobil 1 0w40. No appreciable consumption

2TRFE, 1GRFE


Same. 2007 Tacoma V6 that now has 223K. Uses no measurable oil between 10K OCIs. I've done every oil change, and it's never had anything but some flavor of Mobil 1 5W-30 (and 10W-30 a few times) since its first oil change at 3000 miles.


Same - 130k miles on my 1GR-FE Tacoma and still zero consumption. 5-10k OCI with Mobil 1 or more recently Havoline ProDS.

 

[4WD]

Only one I recall to use oil was a 1979 Dodge PowerWagon - and it was probably 10 years old before it started - owned it and beat on it for 17 years
Have Chevy and Ford 4 bangers each at 120k and not burning oil - and no, my 5.3L's don't either

 

[circuitsmith]

I'm going on a little math journey:

A hypothetical 4 cylinder engine with 80mm bore and 80mm stroke.
That's 1.6L displacement. Each set of rings sweeps over 201 square centimeters of cylinder surface.

Now suppose that swept area gets coated with 1um (micrometer) of oil during compression & intake, then gets burned away on each power stroke.
A 1um coating on 201 sq cm = 0.0002cc of oil.

With tall gearing suppose this engine is moving a vehicle at 60mph and revving at 2000rpm.
That's 4000 power strokes per mile, thus 0.8cc of oil burned per mile, thus 0.8 liters per 1000 miles.
That's in the ballpark of a moderate oil burner.

I can imagine an engine that burns less either leaves a thinner layer of oil on the cylinder wall, or most of that oil stays from cycle to cycle.

 

[Railrust]

I think it depends on the engine. I have a 2008 Honda CRV that doesn't use oil...6,000 mile intervals and there's no noticeable drop on the stick. On the flip side I have a 2018 Silverado that has used oil since day one...around a3/4's a quart in 5,000 miles (it's a V8). Had another V8 in a Lexus LS460...that began using oil at around 130,000 miles, got progressively worse until I traded it in at 178,000 miles.

Do direct inject 8 cylinders ‘use' more oil than other engines?

 

[bunnspecial]

My MKZ doesn't use a measurable drop in 10K miles with Mobil 1 5W-30. I don't recall it losing any either when it was still under warranty and I was using 5W-20 still. It's a hair short of 70K miles and a lot of those come in ~250 mile non-stop(or maybe 1 stop) interstate jaunts so it has plenty of opportunity to boil off(I hate to say "burn off") condensation and fuel.

The old British stuff is another story. The rings are pretty well shot on the MG so I get a lot of blow-by. I finally got some of the oil loss under control by repacking the oil/air separator in the crankcase vent with fresh media and also finally getting a gasket that fit and sealed properly(a long standing complaint on these engines, and someone finally figured out how to cut them correctly). As it was, I'd pretty much lose no oil running around at a max speed of 50-60mph, but as soon as I hit the interstate(4K+ sustained due to no overdrive currently) I'd lose a quart in 100 miles-and I'd see a lot of that in the form of oil droplets on the windshield and a WHOLE lot under the hood and out under the edge of it. I still get some blowing out around the oil filler cap and edge of the valve cover gasket(the former is vented and has its own combined filter and oil/air separator), but it's not as bad as before now that the factory designed vent functions properly. In fact, the summer before last when I was doing ~500 interstate miles a month in it going to club meetings and the like, I kept at least one 5qt jug of Supertech 20W-50 in the trunk, and at times even experimented with SAE 40 to try and keep things under control. With mixed around town and city driving down now, I can manage to add a quart every 500-1000 miles, which isn't great but is a lot better than what it was doing before. There is a partially disassembled short block in my garage now that's going to get bored, new pistons, and new rings and hopefully solve oil consumption as well as it can be solved on an old British engine.

The one that really baffles me-my future sister-in-law(finacée's sister) has a 2019 Jetta that she bought in late 2018. Her job involves both some short-ish trips(~15 miles of surface streets to the office) plus a fair bit of weekly out of office work that often has her doing ~30 minutes+ on the interstate each way. I think she's at around 20K miles, and it's using a quart every 2K miles. . VW insists this is normal. If it were mine, I'd bump it up a grade(spec is 0W-20, and I'd be inclined to try 5W-30) and even offered to change the oil for her, but she understandably wants to use the dealer as long as it's in warranty.

 

[littlehulkster]

I would argue that all engines do burn some oil, however not all engines burn enough oil for you to notice (especially with a crude instrument like a dip stick) nor enough for it to cause any issues.

Say your engine burns 1/10th of a qt on every change. You can't measure that using the dipstick, and it wont cause any problems, but it is still some oil consumption.