Prius Prime oil change frequency?

that's all you can do. i change mine every spring just because i'm concerned about condensation, but i have no idea

 

The Prime shows the EV percentage for various trip meter/odometer selections, so it's not hard to estimate actual engine miles since that's not an indication of how many miles you drove while having EV selected, but an indication of how many miles the car drove w/o the engine running.

I would guess that that is OK now that it's out of warranty. Some people have their oil analyzed to see if it needs to be changed. For me, it's just too easy and inexpensive to change the oil at least once a year as opposed to spending time & money getting it tested or risking an incredibly expensive repair. I'm not saying "Don't do it," but I hope you're weighing the potential risk.

 

I currently have 14,000 more miles on the car since my last oil change. The dipstick shows spotlessly clean oil! I drive 3/4 EV and sometimes 100% EV. Current odometer is 34,000 miles. Last oil change was 20,000 miles. With pure ICE vehicles the dipstick always gave an idea of the condition of the oil in the oil pan.
Is there possibly another reason for this clean dipstick? Or is it related to my % of EV driving? I normally drive 55-60 Mph and only exceed that speed when entering the freeway.

 

there could be, because when you drain the oil, it's a lot darker than it is on the stick for some reason

 

Yeah I find you can have a thin film of oil on the dipstick, barely darker than new, but a cup or two of the drained oil in a clear container is completely opaque. Still, if I check the dipstick on our daughter's Pilot, the oil on the dipstick is completely black, lol.

 

Interesting, totally opposite.

 

What's funny is that you probably have less wear on your 14K mile oil than my pictured race car after roughly a few hours of high RPM racing.


Rob43

 

So I have wondered this myself. Here's my logic : yes, the oil manufacturers say "change every 3/6/12 months" or whatever. But it's not like the oil in the bottle has an expiration date. If the car is run on pure EV mode, the engine isn't turning at all. What "wear" is being done on the oil sitting in the drain pan rather than in the bottle at the store?

I hear the moisture argument, though I'm not sure how valid it is...is engine oil hydroscopic? How much outside air really gets into the engine?

 

I agree, I,m going 20K miles, between changes. If the Virus continues to Dec. then I’ll extend the interval. Right now I am living in a really small town, the other day I used .3 of a mile to get downtown. If the corona virus continues for a year or more,I will never change oil. That will be the least of my problems. We may have angst even to go to town,not for the Corona fear, but for the roving staving mobs, the house breakins even the sudden news the US Dollar suddenly has NO VALUE. We must open up our economy, and take the hit .

 

I have just replaced my oil 0w20 in my 2014 Prius at 44k miles today myself and my 2017 Prime oil change was performed by Dealer back in 18k miles. Now my Prime is at ~29k miles. When I compared the fresh oil in my 2014 today vs the 2017 Prime, the oil in my prime is exactly like new. See photo.

 

So, when will you change your PRIME's oil, now you are on your own.

 

Maybe end of this yr.


iPhone ?

 

I will personally go much longer... my ICE virtually does not run.

Then when it's dumped out I will keep some of it, it will get put into my lawnmower.



Rob43

 

One thing I am worried about waiting longer than 10k recommended oil change interval is if I need warranty coverage. The power train and engine components are covered 5 years/60 K miles. I will stick with the 10k interval at least until that point.

 

Good point but how is the dealer going to argue back or find out if the oil change is done ontime (when the oil is like new)? Maybe there is a sensor or secret behind this car that the dealer can detect

 

Yeah, I think it is very unlikely that dealer would ever ask. And even if they ask, it would be next to impossible to prove that you did not change the oil as recommended in the manual. But you are supposed to follow the regular maintenance as recommended by Toyota. Even with a slim chance that deviation from the recommended oil change interval may result in the refusal of warranty service, I will stick with the 10k interval on my car at least until 5 years/60Kmiles.

Here is the clause on "Maintenance" from the Warranty booklet.
.

 

"12 months or 10,000 miles" for a non plug-in Prius translates to roughly
"600 cold starts or 200 gallons of gasoline used" for a plug-in Prius.

Motor oil is degraded mainly by cold starts and engine revolutions multiplied by load, and revolutions multiplied by load is roughly proportional to energy throughput.

If you keep track of or estimate your cold starts and fuel use, then you can use the above rule of thumb to calculate the equivalent oil change interval for your plugin Prius under your individual operating conditions.

 

Just curious, what constitutes the "cold starts"? And, how did you get the "600" cold starts? I think I can see the 200 gal of gasoline used is based on the 10k miles and 50mpg (10000÷50=200).

 

Just my personal rough estimation of typical commuter car use: Standing eight hours overnight, one cold start in the morning, standing eight hours during work, one cold start in the evening, six days per week, fifty weeks per year.

That certainly varies quite a bit for different use cases, but counting cold starts is likely more representative of oil degradation than counting just months irrespective of use.

 

I see. In Prime, the number of cold starts is hard to count. Some people are driving every day but never using the engine. I usually drive longer than the EV range, and the engine will kick in at least once a day. In winter maybe twice a day, by 8 hours of cold soak definition. But, I have a feeling 8 hours of cold soak in the summertime is quite different from 8 hours of cold soak in the wintertime in our region. I am sure coolant and engine temperature in summer after 8 hours at 80F are much higher than 30 minutes of the engine inactivity in winter at -10F. If so, I do a much harder cold start several times during my daily commute in winter.