I made an appointment to have my oil changed for the first time at 6 months, and when I got there, the service advisor told it it wasn't needed; that I should not come back until I reached either 10K miles or 12 months.

In terms of miles, what percentage is the ICE running? I would think that for most people, the ICE runs at least for 90% of the miles put on the odometer, no? I mean, yea, I run in EV mode, but that usually isn't for any great distance (only a mile or two at a time)?

 

EV mode when you are moving has little to do with it I suspect.... how often are you sitting at an intersection? Your engine is off.... the typical engine is ON and NOT rolling the odomoeter. Where a typical car has its oil changed every 3,000-5,000 miles in reality if it weren't idling it would probably have to be much less often... the 3,000-5,000 is "padded" to make up for idling. People think that the "severe service" schedule in their owners manual is purely because stop and go traffic is hard on the engine but for taxi's and such it really has MORE to do with time put on the engine while the odometer is not turning.

As discussed in a different thread this thing really needs an "hours" meter like farm machinery has. Farm tractors idle alot and are used for PTO operations, so they have an Hours meter of how LONG the engine has run for maintenance.

 

I'm thinking, in addition to lack of idling time that a hybrid ICE has, another factor that lengthens/shortens the oil life is the average load the engine has to put out. With a regular engine, a majority of your horsepower is only needed very rarely - on acceleration - very little of the total horsepower of an engine is required otherwise (except if you're towing something). That's really the major factor in deciding what engine to put in a regular vehicle - the weight of it and thus what kind of acceleration they want to accomplish with that particular vehicle. That large load required during acceleration also contributes to the extra wear and tear on the engine - and oil life.

With a hybrid a lot of that extra load required during acceleration is given over the electric motor. This is also why a lot lower horsepower engine is needed for the ICE on a hybrid - you don't need it.