How often should I "really" change the oil?

I suggest that you get an oil analysis from Blackstone Labs. I did it on both of our Prius c's. Go 10,000 miles and mail a sample off to them.
They give you a very detailed report on your oil. Just a suggestion.

 

They don't give you the TAN though. Total Acid Number which is really important if you only change the oil once a year.

I think you have to pay extra for that on Blackstone. But I would be more concerned with the trans fluid.

Why don't you post that UOA on the Prius C stickies. I have a few trans UOA's on the G2 site.

 

Ed, chemically there will be no TAN if there is still a positive TBN remaining. The base is there to neutralize any acid. If it shifts to acidic I'm sure that you've gone too long/far, and Blackstone will tell you....

Posted via the PriusChat mobile app.

 

Its a quantifying number and will tell you how much neutralization is left. I would like to see that number. If you look at my trans stickies the TBN is still ok but TAN is creeping up.

But whatever.

 

In every car I've owned¹ since I started driving (late 1960s) I've always followed the manufactures' recommendation, but remember (IMNSHO) it's more important to change the oil-filter than the oil (…but as they say YMMV).

¹ Vauxhall Victor, Mini-Cooper, Bond Bug, Austin Champ, Volkswagen Golf, Toyota Tercel 4WD, Toyota Corolla DX Wagon, Toyota Prius Gen II (Touring) …er, that's it!

 

Sounds like you came across the pond about halfway through that list.

 

…well spotted, the red VW Golf was my first set of wheels on this side of t'Pond!

 

On my model, the maintenance schedule calls for 10,000 mile intervals and 0W-20, but I choose to change it every 5,000 miles.

If I was to change my thinking I would absolutely send a sample out after 5k and see how it came back, before I made the change.

 

One thing that hasn't got much mention: these intervals are always miles or months, whichever comes first.

That maybe falls apart with a car that's near-mothballed, but just sayin'.

 

This is what I'm going to run in my Prius in about 6 months when I do my first oil / filter change.

 

In Europe Toyota calls for an Oil-Change every 15.000km, which should be 9000miles.
If you take into account, that very short Trips are also covered as well as "urgent Drivers" which do 100mph frequently, 10.000miles on the Oil the US should be on the safe side.

Oil analysis often show Oil starts breaking down after 20.000km / 12.500miles

VW group an other European brands claim 30.000km without oil Change, but Engines look like that, after 100.000 miles. So that's no recommendation.

 

I have done oil change every 10K since the start, now at 120K Miles. Nothing else (No fluid changes, no maintenance, absolutely nothing) has been done to the car other than 4 new tires at 80K. Runs great, no issues.

 

My 2012 C2 with 112k miles engine isn't noisy with Super Tech 0w20 synthetic oil. You can hear lifters and things if you open the hood and stand in front of it, but with the hood closed and under normal driving conditions the motor sounds perfectly normal to my ears.
The fact is, people get hundreds of thousands of miles on their Prius engines using the Toyota recommended 0w20 full synthetic oil.
When you run an oil viscosity other than 0w20, you're in uncharted territory as far as engine longevity is concerned.
Every car I've ever had has made tappet and lifter sounds when you open the hood and stand there in front of it but I never took that as a sign of an oil issue or incorrect oil viscosity.

 

Any newer Toyota with 0w20 or 0w16 full synthetic oil has Oil change interval of 10 000 miles/1yearunder normal conditions. However, People often do not drive it normally by driving less than 10 miles per trip in cold winter, rarely go to the highway with 60+mph cruise speed and check their dipstick. Or loading the car with 4 or 5 passengers, roof rack, or towing regularly. Those are considered to be harsh conditions/not normal and the OCI will be dropped to 5000 miles/ 6 months. It is written in the manual handbook. We still need to check the dipstick every month/1000 miles because some cars eventually burn some oil. First oil change in 1k-5k miles oil change is very important because of breaking in period with high amount of metal shaving. My Prius is now 100k miles and consumes no oil at all in 10k miles intervals because I drove regularly in the highway and only 2 adults 1 kid in the car. I chose any full synthetic oil 0w20 in sale from local stores. Often they cost about $30 with filter included and sometimes almost free because of rebates. I also change the transmission ATF WS oil every 60k miles with either Valvoline Dex/Merc for only $17 4 quarts. I used Valvoline Dex/Merc in the past 15 years without issue because it is fully synthetic and has Dexron VI approval. Aisin ATF6+ who makes Toyota transmission also compatible with dexron VI, WS, Mercon V LV, etc. That transmission fluid all actually has certain standards and any Dexron VI-certified ATF is more than enough for Toyota WS applications.

 

Toyota will argue that.

 

Redline calls for D6 for a (randomly chosen) 2017 Toyota Prius v FIVE and also a 2019 Cadillac CT6 Luxury 3.6 AWD. Hmmm.....

moto g(7) power ?

 

The only time I ever hear lifters/tappets is from an engine with out-of-adjustment solid lifters - or one with hydraulic lifters and very VERY low oil.