2020 oil changes: every 10,000 miles?

With Prius Prime I manage 80% local driving in EV mode and overall likely about 50% EV mode considering lifetime (including long trips). Plus, in hybrid mode means ICE is not running all the time. So, the ICE typically is only used maybe 50% of the time or less. My 2020 Prius Prime has synthetic oil with recommended change interval of 10,000 miles that is the same as cars that don’t plug in, don’t have EV mode, and are not hybrids. Logically, an oil change recommendation is based on “miles driven” with the implication that the ICE is actually running during those miles.

Can anyone explain why the oil change interval is not longer for plug-ins that run 50% of the time in EV mode (ICE not used)? Same question for hybrids where the ICE is not active during idle, braking, low speeds, and coasting, etc.?

 

History.
Low compression rings.
Closed hood maintenance philosophy.

Take your pick.

If you're going to be trading out your car before it FODs out at 150K, does it really matter?

 

I haven't looked in the Warranty and Maintenance Guide for the 2020 PP, but you might want to take a careful look there to see if you don't find two different recommendations depending on driving conditions.

For example, in the Gen 3 Warranty and Maintenance Guide, you see a 5,000 mile/6 month interval if your driving hits any of several criteria, or a 10,000 mile/12 month interval otherwise.

You can look at that as a 10,000 mile OCI that changes to 5,000 miles if your answer is yes to any of those driving questions.

That's completely equivalent to saying the recommendation is 5,000 miles unless you can truthfully answer no to all of the questions.

That's reflected in Gen 3's built-in reminder, which lights up every 5,000 miles. But again, I haven't checked in the Warranty and Maintenance Guide for the Prime.

 

North of the 49th parallel in Canada, the regular OCI for 3rd gen was 8000 kms (5000 miles) or 6 months, whichever comes first. The severe service halved those IIRC.

 

Tons of people don't plug in their Primes. So they had to use an interval that fit the worst case scenario. I think 10k miles in a regular ICE is too long, but it's about right for a hybrid. And for a PHEV that gets driven like a hybrid, also about right.

 

I think you nailed it.