One more oil change interval post

I think you should be fine, just keep monitoring your engine's health. Regular checks help catch any potential issues early.

 

Well thats what Toyota advises. That'd be once a year for a gen 4.

I've given up on 6 months oil changes (the time interval for our 3rd gen in Canada), going with once a year. We're lucky to do 5K kms yearly.

 

I use Mobil ESP 0 in 20 motor oil. Laboratory analysis of the oil shows that after 15,000 km the properties of the oil do not degrade significantly. It takes 2 years for me to reach 10,000 km on the engine. But if you change the oil once a year at 5,000 km, I consider this wasteful. In fact, this oil has not exhausted its resource. Therefore, I decided to change the oil for myself at 10,000 km or once every two years.

 

Outdoors? What part of the country?

 

I gauge my ICE usage through fuel-ups and use a conservative 50 mpg to determine actual ICE usage. I'm not ready to push out to 2 year oils changes yet, even though I use the 20K mile full synthetic stuff. My lifetime mpg is around 120, when I reset my last service minder lamp.

 

When you fill 4.4 quarts, what do you do with the remaining 0.6 quarts? If you use it for your next oil change, that oil has been sitting in an unsealed bottle or your car for 4 years before it is drained. Does anyone know if that is a problem? I am still doing every 10,000 miles, which is a little over 6 months for me. However, I am probably the perfect candidate to push it out much further. I drive a little under 19,000 miles a year and use only about 20 gallons of gas per year. I am very tempted to at least stretch it out to 1 year, but haven't pulled the trigger. I am a little nervous because most of the HV miles are only 2-4 miles at a time when I just run out of battery on the way home. I haven't found saving 70 dollars a year to be worth it yet. I would rather be safe than sorry. I even get the oil changed on my wife's prius C every 6 months/5,000 miles, but I feel like the engine is working way less on my 10,000 mile interval for the prius prime.

 

If your only doing two tanks a year, that's only 1100 miles on the ICE. That oil must be pristine, send out for an oil analyst if your nervous - around $40. That's cold hard data. When your ICE does fire, do you allow the ECU to warm-up the motor completely or you just shut off the car. If I have time, I'll let the ECU turn off the motor. This ensures full warm-up and burn-out of contaminates.
As far as leftover oil is concerned, I just use the remaining on the next oil change. IMHO, As long as you let the motor get all the way up to normal operating temperatures - all moisture and contaminates are burned out of the oil.

 

Honda uses a maintenance minder which apparently does more than just get triggered by the odometer. It counts down in percent to the next oil change, then displays a code indicating to do oil change, plus various codes for additional. In the Owner’s Manual there’s a section explaining the system and the codes, and at the bottom it says even if the MM has not counted down all the way, at the least change the oil yearly.

 

While this is interesting, it helps Toyota owners nada. All we have is a brainless 5,000 mile countdown idiot light.

 

For me the take-away was Honda’s stance: if the car’s seeing limited use, they recommend a yearly oil change. Come to think of it, that’s Toyota’s policy as well.

Use the odometer instead?

 

The engine may not warm the oil so much after just the warm up cycle. It’s hard to estimate the Prime oil change interval. I’m just going to waste oil, and do it yearly. I want to try different oil filters anyway. Next up is a Fram Ultra which I may just replace by itself since I’m impatient for the year to go by. I want to listen for start up noise differences after engine is off for many days.

 

I’m assuming the Prime ICE is like the regular Prius and has a warm up cycle to insure it is available when needed. If so, that’s the equivalent of multiple short trips that result in fuel contamination of the oil.
An additional thought is, from my understanding of these vehicles, the oil is used for other purposes than just lubricating the ICE and some of those functions utilize relatively small passages.
The $40 (or so) oil analysis is not comprehensive and the ones I looked into do not include enough detail to be informative regarding additives condition (which is one of the primary concerns promoting time based OCI ( at least that is my understanding).
One other thought: the majority of the maintenance items in my maintenance schedule are inspections. Thus if one chooses to follow long OCI’s the shorter time period preventative maintenance intervals still would need to be followed to prevent premature failures.

 

I find it interesting that for the first 13 years of the car’s life (assuming you still have the 2010), you invested time and money in an admirable preventative maintenance program to insure (I assume) a long life for your car, only to abandon it when most people would be being more attentive to preventative maintenance.

 

First off, we are very diligent about avoiding short runs, tend to use the car once or twice a week, and combine car-suitable chores whenever practical. Also, before any cold start, almost without fail, we plug in the block heater, preferably for 2 hours.

I've been following Toyota Canada's 3rd gen schedule, 8000 kms (approx 5000 miles) or 6 months, whichever comes first. For most of the first decade of ownership this was suitable; my wife used the car for work, and that kept the kms around 10k yearly (around 6000 miles). So not too crazy.

Now, with both of us retired, then COVID, and advancing age, our annual kms is lucky to be 5000 (about 3000 miles). Too, winter use is a lot less.

I was doing a spring (mid-April) and fall (mid-October) oil change. Last spring when entering the miles in my maintenance log, I noticed it had been a paltry 1366 kms (about 850 miles) since the last oil change

====
Thursday, October 6, 2022
kms: 95051
* changed engine oil and filter
====
Monday, April 10, 2023
kms: 96417
* changed engine oil and filter
====

April coming up I'll do an oil change, the "spring" oil change. Car's currently at 100,401 km (it passed 100,000 kms Christmas Eve), so about 400 kms this month. Assuming similar usage through to that next oil change, that'll be.roughly 6400 kms since last oil change, about 4000 miles.

Note too: this was an exceptional year; we did a road trip from Vancouver to Williams Lake in early October. Beautiful, balmy weather with our (mandated) snow tires on. That added about 1200 kms.

I've yet to see the oil level on the dipstick budge.

 

Cools it down?