Does 5k oil changes prevent...

The reality is low tension piston rings and the piston groove design were the primary causes of excessive oil consumption in the 2010-2014 Prius engines. Toyota would replace them under your powertrain warranty if excessive oil consumption was present. Excessive was defined as worse than a quart every 1200 miles or three fillups.

However the failure mechanism included carbonized blowby clogging the rings such that the rings would not move in the piston groves. When that happened, the cylinder walls start wearing unevenly aggravating the blowby and accelerating oil consumption. More frequent oil changes early in the engine life or after a rebuild seems to reduce the ring clogging but obviously won't fix existing problems.

Oil seals on the valves also cause consumption. Gen4 engines revised cylinder cooling in several ways which some believe reduced oil consumption and head gasket problems.

 

I'm just here for the theories

 

Theories.
I would say the cause of some oil consumption related to piston rings and bore would be "grit" (carbon, fine metal).
In that case new oil could be advisable.
Yet consumption related to valve seals.
Id say new oil would have a small effect here (eg grit on the valve stem which is theoretically sealed as the value moves through the seal) as the seal's edge prevents grit on the stem with the grit being built up on the seal edges. Now that's theory LOL.

Then consider the 0 or 10 etc weight synthetic oil required.
Plus there are many co-member with Prius's having over 200K mileage.

My opinion, every 10K mileage or two years with synth oil is good maintenance.
Yearly or every 5K is superior with perhaps 5K an "over kill".
Yet as a hobby, cost of a DIY oil change is (maybe) $50.00 and one could go so far as to change the oil, run for 50 miles, and change again having a theory effect of flushing the block of debris.

Yes, a real two cent comment from me

Good luck with your decision.

 

Including conspiracies.

 

The question is not "will dirty oil wear an engine" but perhaps why do so many 2010-14 Prii develop excessive oil consumption especially when other parts of the engine have virtually no measurable wear thanks to quality design, materials and oils?

 

orenji will faint if he sees that, he rolls with w0-40 and that is the true synthetic oil from mobil uno

 

Perhaps something to do with the start/top operation of the engine?

Anybody do comparisons with other vehicles that stop the engine at every traffic signal?

Start-up wear is often the most wear an engine gets - then again - that's usually from turning the engine before it has oil pressure - which is not great for the bearings, though maybe not as bad for rings...

 

mine has almost 180,000 miles and minimal engine wear said blackstone oil lab test results but started burning oil 2 months ago. I’ve heard about engine oil evaporating and going into catch cans.

Or the engine oil fairy is being aggressive taking more than usual and not leaving collateral behind.

 

There are similar cars made by Toyota from 2001-2009 and also from 2015-2021 to compare.

 

haven't found any here yet, just true believers

 

I’m a little incredulous; are you racing??

 

how do you drive a car at wide open throttle the entire time you use it ?

is this race track/autocross ?

 

Its clear that long wait times in Ready and excessive traffic causes 40-50f thermal cycling swings that has been mentioned by some as a possible hg contributor. So its not beyond possibility that reduced thermal cycling caused by high loads could reduce piston ring clogging, resulting excessive oil consumption and hg problems. Interestingly, the egr valve is closed at wot reducing carbon buildup in that system including the cylinders.

 

My 2010 has 97K on the clock and uses zero oil between it's biannual Toyota 0W20 oil changes. I noticed over the years on the board that owners that went to 10K mile oil changes, as well as those owners that routinely drove their cars at higher than normal speeds saw more oil consumption issues than those that stayed at 5K oil changes.

Not in every case but a majority of owners that fell into one or both of the 10K oil changes and driving at 70 mph and above on the highway saw increased oil usage starting around 100K miles.

 

I'm at 125k miles on my 2010, and haven't noticed any oil consumption since I got it (50k miles ago). Note that I'm in Europe so maybe there's something different here? I have the oil changed every 15,000km (9000 miles) with 0W-20. I fill up with whatever the cheapest 95 fuel (US equivalent to 90 octane) I can find is.

 

Luca, I will give you this advice: First, problems usually occur around 150,000 miles and above.
Second, I do not know if the emission system is different on the Euro models, but in the US, these engines have a flaw: The PCV valve allows too much oil into the engine intake.
Result is that engine burns oil, which is hard on the rings. Much worse, it causes oily deposits inside the EGR valve, which can block it. Eventually, these deposits form inside small passages of the intake manifold, clogging them. This leads to blown head gasket. There are many maintenance videos in the Sticky section which explain how to clean and prevent this.

Another problem is that the electric water pumps can fail with no warning — you don’t know something is wrong until the engine overheats.