Hi Raidin, it'll take me about 9 years to get the mileage you drive in a year. I guess I'm old school, change the oil every 7-8k, 2x a year. Have you done regular maintenance on the other fluids like brake, transmission, and coolant? Keep us posted on your mileage and any issues since you appear to be the high mileage champ.

I want to start by saying that if I didn't drive so much, I'd go for normal oil change intervals. I used to do it every 5k, but the engine is so clean and has so little wear that I started doing 10k as the manual says. But considering how expensive it is to change the oil as many times as I do, I decided to try to extend it as safely as I could. You're doing it right for your application, I just wish I could change mine around the same interval you do.

I've changed the transmission fluid twice now, as per recommendations at the Prius forums at priuschat.com (which is: first at 30k, then every 60k).

I've not done the brake fluid because the master cylinder has never been exposed to air, so I'm waiting for the car to get to 2 years old to check or replace it.

The engine coolant had been changed at 100k. I'll be doing it again, along with the inverter coolant, at 150k, as per the manual.

Just curious, but what kind of fuel mileage are you seeing at this point?

I have 206,000 miles on my 2011 CT. I'n hoping to get another 200k more.

Still seeing about the same overall fuel economy?

Yes, I'm getting an average of 42mpg. I haven't seen a drop in mpg.