Rigid 15 000 Km oil changes makes no sense IMHO

I have a friend who drives a 2017 Prime and uses it for his work as a traveling salesman. He racks up a lot of miles but benefits from the charge-up each night. Well I found that after an amazing 10k miles of driving in just 4 months his oil is still very, very clear! Like just slightly darker than new, clear. And in the time I’ve helped maintain the car for him I’ve noticed this vehicle to generally have the cleanest engine oil I have ever seen. I always used full synthetic motor oil and it has well over 100K miles on the odometer. It makes me feel strange to tell him that an oil change is frankly unnecessary if the oil remains clear even after 10k miles but I wanted to get the opinion of the group.

 

Used oil analyses suggest lower metal counts (at similar distance traveled) on engines traveling long distance typical among salesmen vs those on short or start stop driving .

If it were me, I concur with you and wouldn't have the oil changed at 10k miles.

 

Can you hazard what percent is electric-only driving? That said, are you viewing the oil on the dipstick? I’d wager if you drained the oil now, collected some in a mason jar, it’d be black.

 

Water is an enemy. It gets burned away if engine is used enough but it is still there until it isn’t. 15 k kilometers in a fairly warm climate might be ok, my opinion. Water is not going to show in a uoa if it was burned off. The sample for a uoa is tiny. I can’t see spending money on them myself. Leaving oil in long periods like years is an open door to water in the oil just from condensation. This may be the biggest thing to think about in a Prime used mainly on EV imo.
I need to do better about running my engine, maybe once a week at least. Every day may be better, thinking about that, but then it may not warm up fully. So that’s worse even.

 

Yes, you should change your oil every 10,000 miles (16,000 km). It is the most important thing for your engine. Any longer OCI requires an extended-performance oil with more antioxidant (AO), and TGMO does not have it. Some Euro-spec oils may have it.

 

Again, that is a Euro-spec oil with more antioxidant (AO). That is not the case for TGMO. Don't use a regular synthetic for longer than 10,000 miles (16,000 km).

Here in the US, you can get Mobil 1 Extended Performance or Castrol Edge Extended Performance with more AO and specced for longer OCIs, but they don't come in SAE 0W-16.

 

Absurd.

 

Do an oil analysis to get an impartial picture of what's actually going on - rather than relying on a visual observation. For example, I just helped my neighbor do a 5K mile oil change on his 2018 Camry 2.5L and it was black. Non-hybrid, mainly city driving. My Prime is 85% EV 50-50 highway/city, daily driver and my 10K oil change was very light brown, honey color. My change interval is averaging around 9 months. I'm thinking I should move to annual oil changes, since the ICE is less than 15% active during that 10K interval; so wasting oil.

Hope this helps....

 

Well to rephrase my question, is clear oil after 10k miles of driving in 4 months automatically indicate that it is still good to go and still lubricating/protecting the engine as it should, or is it possible that clear oil can still be worn out of its protective properties?

 

Yes.
The lack of 'colours' indicates exposure to lower level of oil oxidation and lower level of combustion byproducts/dirt/ worn metal particles etc.
Check out on Oil Blotter Test other than Used oil analysis.

 

Yes, that's why I suggested an oil analyst - since your giving a professional opinion to a customer. Better to have some independent, third party data to back-up your ascertains. I would also switch to the high mileage 20K mile oil, because of it's better anti-corrosion and anti-wear package. I personally wouldn't push an oil change out that far, but if the oil analyst supports it - it's up to you.

Hope this helps...

 

FWIW, I have two other cars that I almost never drive - because I like driving the Prime so much more. With the few miles that I have been putting on the other cars, I didn't change their oil for three years- each had around 1000 to 2000 miles and the oil looked clean and the indicator said there was considerable life left in the oil. Those cars (2006 Honda Odyssey and 2015 Honda CRV) have no issue whatsoever but it would not be a big loss to me if either or both stopped working. I plan to get rid of both when I feel ready to buy a fully electric car.
For the Prime (2020 Limited), however, I feel totally different and I change the oil when the car tells me to. I am retired, have the time and money to follow the dealer's recommendations, and want to keep the car in tip top shape as long as possible. It has 47,000 miles on it, 92.2 "MPG" on the dash board indicator. I believe that the car would be absolutely fine if I changed the oil half as often, but really don't have a definitive reason for thinking so. Thus, I err on the side of closely following the directions in this case.