Calling a spade a spade

Same place as where you take used motor oil. It all gets dumped into the same tank. If it simply isn't burned, it gets re-refined.

The maximum time for Toyota is one year; it's 2 for the Volt.

 

There are engine flush products (some specific, some general purpose auto chemicals) that can be added to the oil, run the engine for 20 to 30 minutes, and then do the change. They may not help for passages already fully clogged, and could make things worse depending on how they actually work within the oil.

The oil filter actually does a pretty good job of catching the material that becomes deposits. They just clog up and the bypass valve open long before even a 5000 mile oil change. Once replaced a filter about a 1000 miles before the oil change; oil went from black to almost out of the bottle clear. If your oil is black at 6 months, try changing the filter to see if that clears up the oil.

What turns oil black and makes up most of the potential deposits is bits of scorched oil. If the engine isn't running, those aren't getting produced. Oxidation from air is another cause of potential deposits. That will happen over time, but a sitting car won't have as much air exchange in the crankcase as a running one. Water in the oil is more of a problem with a car driven few miles; that leads to acid formation. A half to a full quart of oil will be added with a filter change(for one on the engine bottom). That will add some fresh additives that are there to deal with the acids and keep particles from depositing.

 

You’re very welcome sir! I was born knowing nothing and I learned through hard work and dedication. So whatever knowledge I have I would gladly share and I am eager to learn more and more. There are a lot of very knowledgeable folks on this forum, Facebook groups....etc that I have a lot to learn from and would love to do so!

I started my YouTube channel with one intent. Share whatever knowledge I have gathered through my career as a Toyota tech. Some people will argue and bash and do all kinds of things to prove their point. But the bottom line is if someone thinks any information I share or anyone else shares is not good, they’re welcome to do their own thing and share better information and reach the common goal of helping the community.

have a blessed day my brother and hope you’re enjoying your Labor Day holiday.

 

with only 20k hv miles on my pip, and a lot of engine running justto warm up and shut down over 8 years, i noticed it was reluctant to shut down lately.

an italian tune up did the trick, but i have to wonder what's going on inside the egr circuit.

i change my oil once a year, because i don't drive much.

 

There's only one way to find out.

You have all the knowledge here to do the job.

Time to execute.

 

I think the best fix is prevention. I can not recommend any specific product as the products I have experience with are not sold in stores. We use a product by a company called Leyden that seem to work well. But the rate of consumption you have is very low. Per Toyota any oil consumption at 1 quart or less every roughly 1000-1200 miles is normal.

 

Thank you so much for the detailed explanation. I would be grateful for guidance on the below:

1. Do you recommend that the oil filter also be replaced along with the oil every 6 months or 5K miles (whichever comes first)?
2. There's a Marathon REC-90 (Recreational 90 Octane) pump near where I live. Marathon has confirmed to me in writing that this fuel (supposedly Ethanol-free because I don't see the Ethanol label on the pump) has the STP additives they have in their other regular gasoline for Top-tier specs. My Prime use is all essentially EV with an occassional trip on the highway. Do you see any issues with the below plan:

a. Add a gallon of REC-90 every other month, maintaining the fuel gauge at the first bar (1/10th tank?).
b. Run the engine in Charge-mode over 7 miles every Monday; I have arrived at the 1-mile/day (7 miles per week) metric from Toyota's suggestion to burn at least 5.3 gallons over a 12-month period. The reason for Charge-mode is to assure a hot Engine to expel any moisture in the system, as opposed to HV mode which may not get the Engine hot enough.
3. Replace Engine oil every 5K miles or 6-months and the oil filter every 10K or 12-months.

 

To clarify, the reason for the oil filter change interval question is to try and keep the enviornmental waste to a minimum. I understand used motor oil gets recycled into other uses but I am not sure if the filters are properly recycled and the costs of the recycling.

BTW, thanks for the informative videos.

 

Oil filters can be recycled, that is the oil squeezed out. At least most of it. It's not easy, not sure what percent gets the treatment.

Even "empty" oil bottles are a pain to deal with. For that reason (and cost) I buy my oil in bulk, in a reusable container.

DIY'rs using bottled oil create a lot of soiled oil bottles.

 

Yeah, oil is recycled, but a good portion of that recycling means burning for fuel or heating.
The filters can be recycled now.

Oil filters clog up before the next change. The reason why oil turns black is because the filter is no longer taking that fine material out of solution. That fine material is what ends up as deposits. If that is your concern, changing the filter every 5000 miles, and leaving the oil in for 10k miles will be better than changing the oil every 5000 miles and filter at 10k.

 

Honda recommends the opposite: their schedule alternates between "A" service, oil change only, and "B", oil and filter change.

Changing our oil tends to be months well before miles, and that's 8k kms or 6 months (3rd gen CDN sched). I've changed oil at the 6 month mark with only about 4K kms, and it's black as ink.

And the filter looks only slightly darker than when it was put in.

 

Per the below, good oil can still be dark with soot:
What Causes Black Motor Oil? Is it a Bad Thing?

 

I know the soot doesn't keep the only from doing its job. The concern of others is with it forming deposits in narrow passages, which leads to engine issues.

 

Just thought about that at my latest oil change (40K) last week which I know has a considerable % of EV miles in its 10K.

I would be delighted if Toyota allowed the Prime dash to display EV miles, HV miles, and Total miles all the darn time. So many useful calculations you could make from that. But I'd also be delighted if the dash system clock was set from the nav system clock. Ah, don't get me started.

 

If what you want to know is traction battery-driven EV miles vs engine-driven miles, then the Drive Monitor on the MID will tell you the EV ratio. It will correspond to either ODO, Trip A, Trip B, or after the start. It is not EV mode vs HV mode. What you would want to know for oil change interval is the estimation of actual miles driven by the engine. So, this will give you that number.

In the photo below, my 2020 PRIME with 1934 miles on ODO, 69% was driven by EV (no engine), thus engine actually run only 31% of 1934miles or 599miles in 6 months.

 

The below jives with AMD's suggestion for a 6-month OCI:
"According to the automotive website Edmunds.com, the answer depends more on driving patterns than anything else. Those who rarely drive more than 10 miles at a time (which doesn’t get the oil hot enough to boil off moisture condensation) or who start their car frequently when the oil isn’t hot (when most engine wear occurs) should change their oil more often—at least twice a year, even if that’s every 1,000 miles, according to Edmunds. But commuters who drive more than 20 miles a day on mostly flat freeway can go as far as their owner’s manual recommends, if not longer, between changes. As a car ages, more frequent changes might be in order, but that’s for a qualified mechanic to decide on a case-by-case basis."
Three Months, 3,000 Miles Or Longer?: The Truth about Oil Changes - Scientific American

The above also means that Charge-mode for a hotter oil/engine would be better than HV mode for burning off to-be-stale fuel.

 

I may see things in a different light. The main idea is not to treat your Prius as an EV car only. Yes you can have ethanol free gasoline and keeping the level low and cycle the 5.3 gallons over a 12 month period but you're also not using your gasoline engine as often. If you use charge mode often which is actually a good idea for both efficiency and running your gasoline engine things will be better.

Regarding the oil change I only advice what I would do in my personal car because I'd rather pay 20 bucks in oil and a filter every 6 months and do the oil change and filter change than rest my engine's health on hopes and theories. But that's just me. What you do is completely up to you because after all it's your car, your money and your decision. And whatever decision you make will be the right one for you. I wish everyone the best and hope you never have issues at all in the future.

One note. Replacing the oil filter every 10K and the oil every 5K is a waste of time and money in my opinion. Either replace both or don't. But that is also up to you. This is just my opinion.

 

And that is actually in your service interval under severe service. I wish I can find the picture of the rusted cylinder wall from a relatively newer car with very low mileage that sat for around a year. It was a Camry and it had no compression due to cylinder wash down and when we inspected it with a camera the cylinder walls had a rust ring where the pistons were stopped for around a year. that rust is not going anywhere! You can't hone Toyota cylinders! And that rust was a result of moisture.

 

Full charge here is no different than any other lithium-ion battery context. Perhaps what you mean is that fully discharged is 84% discharged (like 16% charged). (Yes, allowing the battery to fully drain would be detrimental to its life. That's why you should never let your cell phone, tablet, or laptop go below 5% battery charge.) See the SOC vs. charging power curve. The charging current is gradually decreased when the battery reaches a certain state of the charge. The region near 100% is exponential, partly intentionally by reducing the charging current, and you can't really charge it much further, at least without damaging the battery. Sure, there is room to overcharge the battery, but this is no different than any other lithium-ion battery, in which the overcharging issue is taken care of by the electronics. No one is going to wait next to their car so that they unplug it when it reaches 90% charge. Toyota has already figured out where the safe state of the charge is; so, the owners shouldn't have to worry about it.