Excessive oil consumption?

The first time I did the EGR/intake circuit cleaning on the 2013 was at 109k, pretty close to the time the video from NutzAboutBolts was fairly new. The amount of black tar gooey film on the intake ports was incredible (like a 1/16th of an inch thick coating). I used a whole roll of paper towels cleaning up that goo. Mine had been a Hertz Rental car from new to 52k, I did the Toyota Synthetic oil changes at 8k-10k intervals up to that point. My best guess was the mess was some combination oil vaporized and re-congealed mixed with exhaust gases coating those surfaces, some of that had to be getting into the combustion chambers too. While doing that first cleaning I went back to reading the forums (especially prius chat) and it seems the oil usage problems and idea that build up of crud causing sticky rings was becoming a thing. So I decided at that time to attempt some things to prevent the issue on mine as it was not yet using. Looked at all the following-- Understanding this is all opinion based on my experience and not a controlled trial by any means of imagination.

-Researched Lower volatility rated 0w20 oils so less oil vapor in the system (again this was before Oil Catch Cans were being discussed). Looked at several and narrowed down to two with lower volatility (NOACK) scores like Amsoil which is expensive, and went with Quaker State Syn which is cheap and available at Walmart. Toyota Oil was sometimes used if my son who is a Toyota tech was feeling nice and would take it to work to change.
-Tried to pick the best air filter to reduce any particles that might have contributed somehow (literally counted pleats on several (fram/wix, etc) While-- not proven the best guess at filtration based on pleats is OEM.
-Read up on the top tier fuels producing less deposits and decided it was worth a try.
-Have read over the years other stuff about the short trip heat/cool cycles contributing to deposit build up so try to mind it.
-I also talked to my Son about the problems (the one who is a Toyota Tech)-- he thought more frequent (5k) oil changes might help.
-Using the Techron as I didn't want to potentailly damage by wiping the crud off the injector nozzles, and all the "claims" it cleans the fuel system.

Just did the whole job again I expected it to be only 2/3 as bad at 182k as it was cleaned at 109k. While this is all pretty subjective by number of paper towels used, It was only about 10% of the goo as the prior cleaning at 109k. The EGR was only 25%-40% of the build up from the last cleaning. All this stuff was tried in an effort to prolong the life given the frequently discussed weak links of the EGR/PCV systems, and potential to contribute to increased build up causing stuck rings leading to oil usage.

I am GRATEFUL to all the posters on this forum detailing experiences and observation that have helped me try some things to get good service from my PRIUS. THANK YOU!!

 

Is the idea that the 10K OCI is overly optimistic about how well the oil holds up (lubricity wise)?

Unscientific anecdote ahead: my 2010 is burning less oil after a shot of that BGR stuff a couple changes ago. I didn't want to believe it, and Covid did totally mess with my driving pattern in the middle of the experiment. But if believable, and FWIW the point would be: there's oil consumption that starts before cylinder scoring. Gunked rings or valves.

 

I run 15k oil change intervals. No oil consumption yet with 137k on it.

Maybe high consumption is an issue with short tripped and/or babied cars, but my experience has been that long change intervals are just fine.

 

"Premium" gas is not "Snake Oil?" It's just that the timing and fuel map's in the "Prius," don't care. The Prius is optimized, to run on 87 octane so 89/91/93 octane won't change the fuel and timing curve. The car does not care, one would have to hack the ECU to increase timing to take advantage of higher octane and no one has done that, with a Prius AFAIK?

A Dodge Hell Cat for one is designed to produce 707 or 740 or 800 hp on Premium, fuel. The fuel and timing maps are "optimized," for Premium Fuel's. Now I don't know but these day's I am pretty sure you could run one of those on 87 octane if you had to?

But the car won't make those HP numbers on that fuel. It would change the fuel and ignition map and most likely lower the Red Line? My much more modest 92 Tercel, could tell the difference between 87 and 89 octane but not between 89 and 91.

My 86 Mekur Xr4ti, could tell the difference between 87 and 91 octane. It could run just fine on 87 octane but it turned the car into a slug. My 89 Porsche 951 Turbo S, it's not that smart? No chance in He$$ that beast will ever see 87 octane? 18 psi at 3300 rpm at full throttle, on low octane fuel? And you'd best be looking for a place to park! It would just blow the head gasket ... if your lucky?

Now I could try and convince my friend with his 2011 BMW M3, 400 Hp DOCH V8 with ITB to try 87 octane and you know see what happens? I would imagine the car would change timing maps and reduce the redline from 8400 rpm? But I doubt he'd be willing to try and see.

Octane is all about "power," the higher the Octane, the more timing you can run before "pre ignition, and detonation" occurs and the more timing a motor can run the more power it makes.

That's why E 85, is the thing if you can find it and tune a car to run it. 110 Octane out the gate, that let's you run a lot of timing advance! But while E85 is cheaper than 87 octane if you can find it. You'd need a higher flow fuel pump and 30 percent bigger injections and you have to be able to trim down the injectors to get a proper idle. To take advantage of it.

There were flex fuels vehicles back in the day that could run E 85 stock. Most likely the OEM just trimmed them down for 87 octane and opened them open for E85 so they would have been Over Sized injectors stock? And they just kept the timing the same? As it was just about cheaper fuel and not power. But your mileage would be about 30% less with E85 because it takes more volume.

So E 85 seemed like a good idea on paper? But it seems not have worked out in the real world for JQP. But the Prius without being able to crack the ECU? Higher octane does not seem to matter? 13 to 1 compression anyway, with an expanded compression stroke, WTH?? Best to just leave it alone and run 87 octane and call it day.

But some car's do need 91/93 octane or more, it depends on what you drive and what you want to do.




It can be done

 

I've never seen a car reduce redline due to octane. I've only seen them retard timing when they sense knock.

You can run premium fuel cars on 87, but the higher the power density they can produce the less willing I would be to ask much of them on it.

 

That's interesting, A lot of my miles are 150 mile highway trips. And I'm trying this whole series of "OCD" things to prevent the issue, while your getting the good result without all that. Are your trips long? Do you do anything special with oil brand/grade?

 

LOL, Ok perhaps I give OEM's to much credit? The knock sensor would pull timing, and you would feel that so why would you rev it higher?

Perhaps I conflate a standalone ECU with an OEM ECU? But I have a plan B. I'll ask my Bimmer, owning friend if his owner's manual says anything about 87 octane fuel? I can't imagine that motor would try and rev to 8400 rpm on 87 octane? But maybe the owner manual has some input on that?

because sometimes depending on where you are or where your going you can't find premium fuel. Been there done that.

 

You give people too much credit! Many drivers have no clue about vehicles and wouldn't even know the car pulled timing.

I doubt the BMW changes redline based on octane too. How would it know that's what's in it? It's possible that when it senses knock it might reduce it much like the redline changes as you're warming the motor up. My guess would be it just pulls timing until it gets bad enough to go into a limp mode though.

Amazing motors those are! Certainly not one I'd be willing to experiment on, that's for sure.

 

Limp mode would reduce the Redline, and thus save the truly stupid. But kind of extreme I would think?
My "speculation," is that (factory high HP) motors have a low octane fuel map in them that lowers the redline and retards the timing based on input from the knock sensor? You can do that with a Standalone, certainly OEM's could do so as well?

LOL yeah V8, 8400 or 8500 rpm redline DOHC,V8 and 8 throttle bodies? It wail's at redline for sure. And I have no chance of getting him to put 87 octane in it to you know see what happens? But the owners manual might give some input on it?

The downside a few years ago one of the two TB's went out on it. It was covered under warranty but it was a $3500 part! And one of the rear sway bar bushing's went bad. No big deal right? LOL to change the rear brushing you have to drop the rear sub frame? But that type of failure was so rare that the dealer flew in tech's from Germany to see what was up?

He has a bit more than 100,000 miles on it so far. And I try and talk him into getting a "Prius," to keep the miles off of it. But he won't have it. It has a timing chain but it has plastic guides! And the Germans and plastic don't have a good record!

As of a few years ago that is a 25'000 dollar motor and I am pretty sure it is an interference motor! I dread the phone call from him, if that happens (the guides break), but so far so good.

 

At 100k if he hasn't done rod bearings he should have them done asap. Those motors have been known to need them at less mileage.

 

Thanks, but he got those done awhile ago.

The timing chain is just me. No service interval on that AFAIK? But plastic parts on German Cars are crap! These day's a forty dollar part can take four hours of labor to get to. And if there is a messed up nice person backwards, overly compilated way to do something ,,, the Germans will go with that. The speed and reference sensors on my 951 come to mind. And yeah I gotta change the Rod bearing's on it sigh, (Also) when I get it running. The number two rod bearing on the turbo 951's can be an "issue" on it.

The Prius is pretty boring maintenance wise, it just goes and goes.

 

It's a rideshare car, so it does it all, city, suburbs and highway runs for a few hundred miles a day when it works.

Oil has been Amsoil 0w-20 until 120k when I switched to 0w-30.

EGR cooler and manifold cleaned at 98k when I did plugs. It looked decent, definitely not close to being clogged, but I did pressure wash plenty of gunk out. Plan is to do it again next time plugs are due.

No oil catch can on it. Toyota air filters and pretty much 99% Shell fuel. It just keeps on ticking along.

 

I've been tracking BMW since the 90s. There's a reason the Prius is the work car! Love me some low maintenance.

 

Thanks for the explanation-- Your care regimen seems to be pretty deliberate and working.

While not always religious on the TOP Tier fuel usage, have been more so the last few years just running the 87 octane from Costco, QT, and occasionally Shell.

Did some searching around and looked up the volatility loss % NOACK specs on the oils. It's really interesting as your choice Amsoil 0w20 8.5, vs QS 10.7, M1 10.1, Toyota 12.9. Amsoil 0W30 8.8. I've never tried that brand of Oil due to the "MLM stigma" and not readily available to me. It's something I'm going to re-consider in the future.

 

how much will 5 quarts cost you with that oil ?

 

I joined Shell fuel rewards and Shell is actually cheaper for me then the local discount chain so it's an easy choice there.

MLM scares lots of people away from Amsoil but they have a huge variety of great products. I use them in just about everything I own except the track car. Their old school marketing hurts their image to some, but the products have always proven themselves. If you're going to do short intervals it's hard to make a financial case for the engine oil, unless you use their lower tiered options. Then I'm not sure they offer much of an advantage over other OTC brands.

 

My cost is $9.80/qt plus shipping, which is a big variable. Sometimes it's free sometimes not. A $60 oil change over 15k doesn't make me cringe considering I have less down time and all the results seem excellent so far.

 

Did you use the Hybrid kit with the 3 different components, or just the oil cleaner? While neither of mine are burners yet, My oldest son has a 2005 with slight usage and we have been afraid to try it. This is based on a bad experience with a crankcase cleaner of a different brand I had tried back in the 80's. It seems a lot of users have had some improvement trying BG.

 

Super Tech.
< $3/qt
<$2.50/qt if you catch the 12q box on sale.


Done.

 

true. If you do 3 5,000 mile oil changes, the amount is about $60 so you might as well go with an oil with detergent and addictives that will take better care of an engine for 15,000 miles.