A few questions about my prius

Sounds like a nice place to live...

Use 0w-30 synthetic during the winter months. Switch to 5w-30 synthetic during the warmer months. As recommended above, change your oil every 5000-7500 miles.

Btw, it was 75 degrees and sunny today.

 

Absolutely. Normally our Prius is garage kept, but we're up in North Dakota visiting family for the weekend. We drove up last night and it was already hitting -15 F around 10 PM on some stretches of I-29. Even going 70-75 with an arctic headwind, and a full car, we still managed 39 mpg.

We had to leave the car out last night because there's not enough room in the garage for all three cars. I went out this morning after everyone else left, hoping to pull the car into the garage on EV only so I could plug in the EBH. Instead, the ICE turned on the second I hit the power button, and it was not happy. I think it hit about -23 last night and when I went out to move the car, it was about -10.

It still has the 5W-30 from California. I seriously considered changing it for the cold this winter, but it had just been changed before we shipped it in August, we only had put about 1000 miles on it before the cold hit, and Toyota shows it safe down to -30 in the manual. This winter, I don't plan to leave it anywhere that it will reach -30 for any length of time, and I don't plan to start it at that temp. even if it does. I have a heavy duty battery pack in the back so if I need to run the EBH in an emergency, I can run it off that for 30-60 minutes. I'm due for a change in the spring based on the mileage, then will change it out to 0W next fall/winter.

 

If you use the dealer to change your oil, check beforehand to see if you can bring your own in. That way you can get the oil at a lower cost at another place and they generally will take the amount for new oil off your bill.