Burning oil at same rate regardless of oil thickness --- What does it tell us?

Yes you can see the holes around the bottom grove in the piston. This grove is the position of the oil control rings and there job is to wipe the oil off the cylinder wall as the piston goes down the bore. If those holes get blocked "particularly in the area where the skirt is longest the oil cannot travel through the piston and returned to the sump, giving rise to high oil pressure at that point forcing oil up past the rings. The Prius pistons are coated as the one in the picture.

John (Britprius)

 

This "problem" is not restricted to the Prius.
You have to remember we are talking about an engine that not many years ago 100,000 miles without a rebuild would have been unheard of particularly in a car with a small engine.
I believe in the UK we have been using higher specification oils "synthetic" for longer than the US. These oils have shown "along with better engine materials and improved tolerances machining" remarkable results. In the US we still hear people are using "dino oil" reserved now in the UK for our old bangers.
We take it as the norm now cars not consuming oil to the point where many people no longer check the oil in there cars, a big mistake. The oil use most people are seeing in there Prius is far below that that a few years ago would have been normal for a new car, and is still below what Toyota accept as being reasonable.
We have people on the forum that are at 300,000 miles and there cars are still only using a comparatively small amount of oil when in reason there engines are well past there sell by date.
If your car uses a little oil it is no big deal providing it is not a traveling smog bank and passes any emissions tests. Check the level regularly and top up as required.

John (Britprius)

 

It's not as big of a problem as you seem to think. We see far more people here reporting dead traction batteries than *serious* oil consumption problems.

Use a decent quality oil, change it on schedule, check it regularly and top off as necessary. Just do those simple things and in at least 90% of instances the engine will outlast the rest of the car.

In your particular case you seem to be way premature in worrying about oil consumption. You've lost what, about half a quart in the last 3000 miles. Well that's nothing anyway, but you haven't even established a trend yet. Seeing as you're not in a cold climate, just change back to 5w30 at your next oil change and start monitoring it for a trend. Check it regularly and keep a log of any top off oil added. You'll soon figure out what the oil consumption is trending.

BTW. My Prius is at about the same mileage as yours and I'm trending about 1L/9k miles. I top off about a third of a liter every 3000 miles. This is not even a slight worry for me.

 

Yes I may just be a little paranoid about these little things that come up. I'm definitely going back to 5w-30 this weekend. I don't even want to wait, just drain out the 0w-20 stuff and go back to what's been working.

 

If I had to do it all over again, I would... (will quote items from Walmart for simplicity)

Treat Cycle (I say Treat instead of Clean to avoid confusion)
Use Quaker State Ultimate Durability - reasonable Group3 Synthetic compatible with ARX
Add full bottle of ARX
Use Oversize Supertech Filter - ST3600 - will take an even 4qts to fill
Run for 10,000 miles to maximize ARX treatment - check frequently and top off

Rinse/Treat Cycle
Change oil with QSUD and ST3600 filter
Run 2,000 miles for rinse
Add full bottle of ARX
Run 8,000 miles for treatment

Repeat as desired until results are satisfactory

Use ARX maintenance dose with preferred oil and filter
I have been running Mobil 1 Extended Performance on 15,000 interval

Commentary
I refer as Treat instead of Clean per ARX instructions because people assume Clean removes contaminants. ARX supposedly loosens gunk and you need Rinse to remove stuff from surfaces. Using larger filter will filter better and hold more contaminants - also let's me use exactly 4qts without overfill. Running 2,000 miles initially without ARX accomplishes Rinse phase, then you can stretch oil out to full 10,000 mile interval with ARX treatment.

Lots of angst and arguments over whether ARX is snake oil - Frank the owner is a real A$$
I think people have expectations that it will strip everything clean and gripe when they see varnish under oil cap
Objectively, ARX users report increased compression with gauge readings and I think this is where it is best used - to free compression and oil control rings

It worked for me within 500 miles of addition - less than 1 week

I am very interested in whether it works consistently in similar applications or whether I got lucky

Instead of everyone piling into Auto-RX immediately, maybe AllenZ can keep us informed on his progress

Good Luck

 

This seems awfully strange but I recently bought a 2010 prius five that's been serviced from the dealer since day 1. It currently has 59,500 miles and last service was done at 57,xxx miles with ow-20 oil. I just checked the oil today and noticed it was reading in the middle of the two dipstick marks. I know this engine is nothing similar to my 2008 engine, how the heck can it be using oil this quickly? Something doesn't seem right.....is this 0w-20 oil really not suitable for these cars?

Britprius seems to be using the same viscosity in England and he doesn't have any problems with oil usage. something just doesn't seem right.

 

Top it up and then see if it uses any. They might have made an error at the dealer. Or there may be a leak. the insulation material on the under cover can absorb a lot of oil before it appears as a leak on the ground.

 

Allen,

I think I am kind of in the same boat as you where I think I have got enough value from Ema so don't feel bad about trying a few different things. Especially if we find something that helps for others in the future. I have tried quite a few things with limited difference and have mostly posted in this thread:

2008 Prius - burning oil at 135,000 miles | PriusChat

10W-40 seems to have helped the most so far and I just got done trying some LOS and it may have helped some. LOS seems to be just like 50 weight oil so other than thickening more not sure it helps much. I haven't tried Liquid-Moly or MT-10 yet but may try both of those at some point.

Let me know how the "Engine Soak" goes as I have been interested in that option as well. If Ema starts burning oil faster I will probably go with a replacement engine for her. I just don't like the flying bridge on the Gen III's and really don't like being forced to 17" wheels to get DRCC.

Happy driving and let us know how it goes.

Chris

 

Did you check the oil just after a run? or did you check after the car had stood for a while?
It is also quiet possible the dealer did not completely fill the oil particularly as the previous gen2 version was known to have problems with oil overfill.
The 2010 gen3 requires 0w/20 oil as stated on the oil filler cap and in the handbook. The engine used in the Auris hybrid uses the same engine as the gen2 Prius also specifies 0w/20 oil.

John (Britprius)

 

I bought the car 3 weeks ago but it's been at the body shop for a dented fender repair. I don't remember the oil being low when I checked it just before I bought it. But I could be wrong. I've only had it in my possession for a couple days and doing a complete inspection today. I'm thinking you are correct in the dealer not wanting to overfill, it's off by just about that qtr/half quart amount. I topped off the oil with half a quart, brought it up to the full mark. I'll watch it and see if it goes down. I did read some other threads about oil burning at low mileage on the gen III so hopefully it doesn't apply to the one I just bought.

 

Hope it was just the dealer, and everything is fine for you.

John (Britprius)

 

Come to think about it, it might have been low when I first bought it. It's the case where one side of the dipstick reads differently than the other side. I must have seen the mark at full when I flipped over the dipstick....but that was probably not a correct reading. I just found out from Patrick and other helpful members that I should use the lower reading as the correct one.

 

To get a correct reading, remove the dipstick and wipe it. Wait about three to five minutes and try again. The extra oil that gives the false reading will have drained out of the dipstick tube.

PS I'm coming up to about 120,000 miles and my level doesn't change from service to service.

 

Thanks for the information. Do you use the 0w-20 oil? Do you check your oil often to know it's not using any oil? I notice I get different readings when the oil is towards the middle of the 2 marks. One reading on one side of the dipstick (lower side), flip it over and it will actually show full.

 

The recommended grade in Australia is generally 5-30 synthetic and this might vary according to climatic zones. Our recommended oil change intervals are 10,000 Kms. The manual here gives a fairly extensive range of allowable oils. I do check it almost daily.

PS. I drive a 2010 gen III.

 

Since you're experimenting, you might try a heavy duty diesel oil like Mobil Delvac 15W40 or Shell Rotella 15W40.
A new post on the 299,999 mile club claims that their Prius with over 300K miles does not consume very much oil using the Mobil Delvac. (I'm skeptical about this claim but what have you got to lose?)

You won't be able to try it until spring arrives though. We've been cursed with a cold winter in the Great Lakes region since late November this season. And it's getting colder still.....brrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr.

 

I would assume the claim you read had an engine that didn't consume 5 quarts every 3500 miles. Not sure any miracle oil can stop a usage of 5 quarts every 3500 miles.

 

If it buys him a little more time, it might be worthwhile for him to at least try it.

As I said, I was skeptical of the claim on the 299,999 mile club post.

 

I freak out when my engine is consuming 1/2 quart in 3000 miles. Not sure what I would do if I had to add 5 quarts in 3500 miles....probably retire the engine for another one.