Metallic flakes in engine oil after WOT!

Are you sure it's metal? If you're lucky, it's carbon deposits that got knocked off the cylinder walls.

 

You should be changing the oil at 12 months max, on the US schedule (the time component governs). So you're about 6 months overdue. Also, an engine with thin oil like OW20 will be more vulnerable at high ambient temperatures.

WOT equals Wide Open Throttle, right?

 

Have either of these authorities got a series of UOAs to back up their statements? It isn't uncommon for oil to pick up moisture and the "water" content in a lightly used car with an ICE that is run intermittently like a hybrid would be even more liable than normal to have high water content in the oil. Seldom gets hot enough to get burnt off.That is the reason why the one year max frequency is recommended. I do it more often and even changed the oil at 1k and 1 month even when the dealer didn't recommend it. 5k thereafter.

A UOA would confirm that your driving pattern would allow you to stretch the interval or show you that you needed to shorten it.. Get a kit, send in a sample, get the analysis with recommendations and comparisons to other similar engine models and mileages.

But sounds like you have serious problems. Bearings, rings, etc.

UOA = Used Oil Analysis, one source is Blackstone Labs
ICE = Internal Combustion Engine

 

Just change the oil and don't drive it hard, you will be fine.

 

0W20 is for fuel efficiency. if you run it like a race car, 10W30 or higher is better suited. it even says so in the owner manual. and yes, by the book, it should be changed at least every 12 months. i suspect the oil sheared down under the short tripping conditions you drive and it's not good enough for your torture now.

please post picture of the filter. it there is no metal in the filter, no problem. you can also upgrade to a magnetic drain plug. that will give an easy visual indication of metallic wear each OCI.

 

Yes, my owner's manual hints at the possibility of using higher viscosity than 0W-20, but is extremely vague:
"SAE 0W-20 is the best choice for good fuel economy and good starting in cold weather."
Then three paragraphs down the page,
"An oil with a higher viscosity may be better suited if the vehicle is operated at high speeds or under extreme load conditions."
There's no recommendation of a specific higher viscosity rating for those circumstances, or a temperature range, or a clue what effect using higher viscosity will have on warranty coverage---or on engine longevity.

Yes, please report on what you find in that filter.

 

i have considered 10k instead of every year, but now it sounds like a tactical error.

 

...take a look at the recent post about Infineum oil tests...they tear down some Prii and Camry hybrid ICE motors...the pistons on the Camry look pretty beat (taxi service I think). Metal flakes not normal as far as I know, one would think oil filter picks that out unless filter is damaged. If filter is damaged, conceivably metal flakes sitting on bottom of pan could be recycled around.

interesting oil study by Infineum | PriusChat

 

I'm at the other extreme, low mileage, following the Canadian 6 months or 8000 km's. I better not let on how many kilometers between oil changes.

 

most likely they got filtered out - you will find them in oil filter.

As for origin it could be anything, bearings, oil pump or just old factory machining leftovers. For machining shavings had seen those after several oil changes. As others say if your 8k come from short trips oil can pick up moisture or get diluted by gasoline. 1hr+ drive usually gets the diluents evaporated, but if you don't than it is better to do 5k changes.

You can opt for 0w30 oil, but MPG will suffer.

 

yes, the CAFE regulations force toyota to specify only one viscosity, the one that is used for EPA fuel efficiency testing. if you check owner manuals outside North America, 0W20, 5W30, 10W30, and 20W50 are all acceptable, subject to min temp restrictions.

 

That's interesting! It seems to confirm those who insist anything but 0W-20 will wreck a Prius engine are all wet, and that, outside of extreme cold conditions, Toyota's 0W-20 recommendation for the US is based more on political and legal considerations than the engine's physical needs. It's funny that higher viscosity is OK in warm places with higher fuel prices, where fuel economy ought to be a higher priority.

 

0w20 should be O'k even for extreme conditions. We went through Death Valley and Mohave desert last August, with temperatures exceeding 108F (42C) with no noticeable ill effect. Granted I was not running it at WOT on 6-9mi climb out of Death Valley. We have considered changing oil to 0w30 prior to trip but decided to stay with ow20.

I suspect the OP issues are more related to fuel contamination than to oil viscosity. If he just drives around town with short trips oil would not have a chance to warm up sufficiently to evaporate diluents. Fuel contamination is easy to detect, smell dipstick next time you check oil level. You got it if it smells like gasoline.

 

have you considered blackstone oil analysis?