Any way to reduce motor oil burning? Is this car worth it?

You have to test the oil burning issue properly. Get an oil change for the car and start when the car oil is full. Then you look at the level every 200 miles or so until you determine how much it's burning and at what rate. From the full to empty mark on the dipstick, that equals 1.6 quarts of oil. So if you've driven 500 miles and the oil went down half way from the oil markings, you would have burned almost a quart during that time. Keep in mind, the faster you go, the more oil the car will burn.

Also you should not use 0w-20 oil for the car, go with something slightly thicker, 5w-30 grade will help reduce the oil burning.

 

Since you put in a high mileage oil, you'll need to continue that route.

Those oils have additives that swell the soft components to help reduce oil consumption. If you go back to non high mileage oil, the consumption will get worse.

Our old 2010 with over 200k miles when we sold it was burning a quart of oil every 5 k miles. I was running 0w-40 oil in it at the end of our ownership along with BG Products MOA to help keep the oil basic.

Since you Prius ran out of oil, it will have a worse case of drinking, but top up as needed and measure the consumption rate.

 

You'll want to get on this quick. When the oil is burned, only some of it is burned in the engine. The rest gets tossed out the exhaust, where it is burned in the catalytic converter.

Thing is, the catalyst isn't built to handle that volume of oil coming through. It's happy to chug a little here and there, but this is an extreme case. At some point, the catalyst will foul over. It might be repairable with an acid bath or other technique, but maybe not.

And because you are in California, the state would require you to replace it with the very expensive original Toyota catalyst- no substitutions allowed. This is part of what they're checking for when you do your periodic smog inspection.

We don't know how long this car has been burning oil, or how clogged the catalyst might already be.

There are techniques for reducing oil burn- they vary from using a different oil to additives to disassembly and manual cleaning with lots of different price tags in between.

Mostly I just wanted to make you aware that this problem is capable of snowballing and affecting other parts and systems. The cost of extra motor oil is the least of your worries.

 

A lot of people do it unnecessarily.

They are incredibly simple parts with very few failure modes and it isn't hard to just wash a dirty one and put it back into reliable service. There's a tricky gotcha involved in removing them from a Prius for testing, cleaning or replacement, but that's it.

Point is, a lot of people fall into the trap of changing it "because it's so cheap" when there was never anything wrong with the old one.

 

Doesn't hurt. But for sure install an oil catch can. Check the EGR system too.

If it's really run-away consumption you better get a new engine in there quick, or just sell it. Do disclose the issue.

It's effing sad, this is the lemon gen of Prius.

Some links/info on Oil Catch Can and EGR cleaning:

EGR:

The simplest way to see where you're at, is to check the degree of carbon build up in the EGR pipe, a stainless steel connecting pipe between the EGR valve and intake manifold. Watch @NutzAboutBolts video #16 here:

Nutz About Bolts Prius Maintenance Videos | PriusChat

Two or three other videos linked there too, for the full cleaning of the intake manifold, full EGR clean, and Oil Catch Can install.

Good thread:

EGR & Intake Manifold Clean Results | PriusChat

Another:

Oil Catch Can, Eliminate that knock! | PriusChat

Some tools worth having:

E8 Torx socket (mandatory)
E6 Torx socket (optional, but good to have, to remove the throttle body studs from intake manifold)
3/8" ratchet wrench, regular and long handle, flex head, you can never have enough (or 1/2 plus reducer)
1/4" ratchet wrench, or 3/8" to 1/4" reducer
Ratchet extensions: you can never have enough
Long needle nose piers, straight and bent tip
Ratcheting 12mm box wrench (optional, but makes disconnection of the EGR cooler from exhaust easier)
Torque wrench (3/8" and 1/4" both good to have)
Floor jack and safety stands (or ramps): basically some method to raise front, if you need to take underpanel off, which you may need to, both for access and to recover dropped items.

Comment regarding clamping of coolant hose, mentioned and or shown in videos:

1. When removing the intake manifold for cleaning, you do need to lift the throttle body off the intake manifold. Still, the coolant hoses connected to the throttle body have ample slack, enough that you can leave them connected, and just tie the throttle body to something adjacent, say the inverter wiring harness.

2. When removing the EGR cooler, removing coolant hoses is necessary, but if you drain 2 liters/quarts from the radiator drain spigot prior (into a clean container), the coolant level in the system will be dropped below the EGR components, and you won't spill anything. Just be sure to not tip the cooler when lifting it off (and catch the rear gasket): there are a few tablespoons of coolant trapped at the lower back corner.

Pour that into your previous drained coolant, and when done pour it back into the reservoir. If you've got the coolant bleed bolt (2010, 2011 model years), leave it open while pouring the coolant back in, till coolant starts coming out. For later model years, leave the topmost coolant hose on EGR disconnected till coolant starts coming out. Also, might help to burp the main radiator hose as you pour the coolant back in.