Need advice from Experienced Plug in Hybrid owners

They did not make any Plug in hybrids in 2008, so I assume your info is incorrect.

I am unaware of any Prius ever with a 7,500 mile Oil Change Interval in the US. So that is no clue what you own.

Whatever you own, follow the Maintenance schedule as described in your manual.

As an example, here is the manual for the 2020 Prius Prime. the schedule starts on page 42.
https://www.toyota.com/t3Portal/document/omms-s/T-MMS-20PriusPrime/pdf/T-MMS-20PriusPrime.pdf

 

Was at the dealership this week getting my first scheduled maintenance on my 2018 Prius Prime. They went over the maintenance schedule, noting that the Prime only needs an oil change every 10,000 miles, so I'm not sure where you're getting the 7500 mile change.

Do you have a plug-in hybrid (i.e. the Prius Prime) or just a regular hybrid (i.e. the Prius)?

 

this is the negative side of a phev. no one knows what kind of abuse the engine is going thru, when it rarely runs, and at that, it's just warm up often times.

i am in the same boat, but i have decided to just change the oil once a year. i cannot tell you how this will affect the engine in the long run, but only having 20k on it in 7 years, i'm not sure it will matter.

 

Good point and part of the reason I went with an extended warranty. Would rather put that risk on Toyota than myself.

That being said, I would say stick with whats in the manual for the regular 7500 mi service. Modern oil and engines seem well designed to go way past the old 'change it every 3000mi' advice.

 

Don't forget, oil changing isn't purely based on mileage, it's based on age as well. Even if you never run the engine you still need to change the oil.

I don't know how long synthetic lasts (probably a while), but I wouldn't go past 1yr with it.

I'm just gonna change mine every 10k (I do that within a year). Even if the engine never runs...

 

Yes, forgot to mention that! Prime manual says 10,000 miles/1 year. I often hit the time limit before the distance one.

 

What is the basis for this assertion? How does the oil deteriorate just sitting in the oil pan?

 

Not 100% sure, but a relative of mine has a few classic cars and if you're not going to use an engine for awhile you drain the fluids so it doesn't gunk up. As I said, synthetic probably lasts a long time, but $35 for 5qts of 0w20 and a filter is a small price to pay annually to ensure it's all good. I could probably do 1hr of research and find out, but I'm lazy.

 

Two ideas.

Like Brake fluid, engine oil attracts water and water is a poor lubricant. This should vary by location.

This is especially important if the low mileage is short trips, where the water does not boil out.

So 'low mileage' where the engine runs a short time, would be much worse than 'low mileage' where the engine never runs at all.

I am doing MUCH less driving now that I am retired, from 30,000 a year to about 8,000 miles, so I am on the time, not miles schedule. But I drive long distance when I do drive, both Memphis and Jackson are over 100 miles away, so I do not drive short distances, I drive rarely.

 

It's not real complicated. If you want to keep the manufacturer's warranty in effect, follow the oil change schedule.