Oil consumption concern

Wait, you're essentially throwing yourself under the bus for not breaking-in your previous car. Who does that?

I'd love to know what car this was. Consuming 1 Quart in 300 miles is far more than excessive. That should have triggered a lemon buy back.

Back to Prius: We've had our Gen 4 since new in 2016 and now have 77K miles. I've never lost a drop of oil in that time. Same experience in all our previous Prius cars.

 

Curious what was it?

 

I think he's on your side.

 

I could see dealer abuse in Alberta during the winter, before you got the truck. Driving home at -20 shouldn’t be what caused it. The Prius has 0w-16 oil and probably harder for them to abuse on the lot moving it from spot to spot, even if they try. Start cold, turn off, repeat over and over. It also has more of a fixed starting cycle. The Prius also probably wasn’t there very long.
Very easy light throttle driving on a new engine is probably not good for it, after the warm up period. You want some moderate acceleration to seat the rings.

 

I didn't have any oil-consumption issue with my new Corolla and Priuses. I have always used the recommended SAE oil viscosity.

Yes, always break in by driving very gently for the first few thousands miles (keep the speed below 55 mph as much as you can). In fact, always drive gently even after break-in, which will not only make the internal-combustion engine last longer and consume less oil, but it will also make the HEV/PHEV battery lose less capacity and last longer.