What's with exclamation mark sign?

If it's only down a quart I don't think it would trigger low oil pressure sensor. That's assuming the oil change place is correct. I would verify:

With the car on level ground, remove the dipstick and wipe it dry. Wait 5 minutes (this gives the oil that gets pulled up when you withdraw the dipstick time to drain back down. Crappy Toyota design...). Reinsert the dipstick, all the way, pull it out, hold it horizontal and check in good light.

You should be able to see a clear wet vs dry boundary. Flip it over, check both sides too: sometimes one side is cleaner, easier to read.

 

Just as I thought. So your car is burning oil.....not leaking. You need to learn to check it yourself every month or every 1-2 thousand miles and refill it yourself and don't wait for the oil changes.
Otherwise you will be buying a new car soon.

 

Mendel he said down TO a quart.

 

We had a fella who did the same, had some brake issues and we pretty much said get codes retrieve. He refused to do so but still wanted to know what the fix is. He said I was "nagging" him, that was the perfect time to try out the "ignore" feature.

 

Ah...

In other words, he had to pour about 3.5 quarts to get it to the full mark?
Then it could well be the low oil pressure warning, going on/off intermittently.

 

Last time I checked, these cars have an elongated plastic undertray covering under the car.

 

He couldn't tell if it was low because it was "too light"...meaning there was nothing on the dipstick at all. So I had it figured out...he didn't know how to check it. That was probably his first time. California?

 

Prius (generally speaking) don't leak oil, they burn it. You've been starving the engine of its life blood many times. At the very least, take this as a dire warning to check the oil every fill-up till you get a firm handle on the loss rate. At the very worst, you'll need a new engine down the road.

GOOD LUCK!!!!

 

OK, so nudriver, listen up!
It's ok to go 7-10k miles on a synthetic oil change, I do it myself, Especially if you're going to be adding new oil between those oil changes. But the 2010 to 2014 are known oil burners once they get some age and miles, so you need to check it periodically and not wait for the oil change. Every time that ! light comes on you are damaging your engine. Don't wait for it to happen, stay ahead of it!
Also keeping the car outside has nothing to do with how much oil it uses.

 

Yeah, if there was 1.0 qts remaining, it's miles below the bottom of the dipstick. Tried to do this accurately:

 

Mileage would be good to know, although at this point it may be irrelevant.

does the engine still run and sound normal?

 

See post #1, last 2 words.

 

That's probably only 'accurate' for a non-tapering, straight-sided crankcase....

 

Irrelevant, there are several ways besides leaks to lose oil.

With fresh 0W-20 oil and a new engine, this is possible, Mendel describes how to find the level,

But if the oil was changed 7 months ago and you drive normal monthly miles, it will no longer be too light to see. If you couldn't see it, then there was none on the dipstick.

That is much closer to a fill-from-empty than to a topping off.

Oil change interval is not the same as oil level check interval. Checks must be more frequent, if you want to keep your engine. When the oil starts burning or blowing through the PCV system, it can get too low much sooner, as yours did.

Your engine has now become an oil burner, and running that low even once makes it worse forever. Now you must check the level much more frequently. The next check should be in about 500 to 1000 miles, then adjust from there.

 

You beat me to it. That's almost exactly what I was going to say.

Engines are like teeth. You only need to floss the teeth you want to keep and you only need to check the oil on the engines you want to keep.

 

Orrible Oracle Always amazes me.....

 

Definitely missing there.

 

In your shoes, I would never buy a good car, and just stick with beaters.