How fast from when oil burn starts to essentially the car is not usable?

welcome!

assuming 7 hours x 60 mph = 320 miles x 2 = all of your oil in 640 miles, i think it's already toast.

i think toyota's limit is 1 qt/600 miles max.

but i don't think anyone can tell you how long.

all this is very unusual for a 2009 with 120k. have you owned it since new? i would dump it if i were you, and buy a new one before harvey drives the price up.

 

What's with Prius wheel bearings frequently failing? I read somewhere they're a design that reduces rolling resistance, but they're not as durable?

 

i don't recall that many getting reported here. i would call it unusual before 100,000 miles.

 

Really??

 

you can always drop a used motor into it for around $1000 and get a few more years out of it

475? higher or lower?

 

Oh dear...

 

the good new is, the engine is in better shape than i thought.

now you know why i can't fix the database.

 

Seems to be more of a problem in regions with winters. Might be related to salt used on the roads? I have replaced 5 front wheel bearings on our 2 gen 2 s over the past 6 years. I seem to get about 60 thousand miles out of each bearing. I replaced the last one myself and took apart the bearing to see if I could press new bearings into the hub. I discovered you can't because the outer race is machined directly into the soft iron hub and somehow surface hardened. The surface hardening is very thin and once it wears through the hardened ball bearings eat away the soft race.
Very bad design for cost cutting, in my opinion, but I would not dump a car over it.

 

I had a 1992 Toyota Tercel over 100k miles that burned a quart every fuel tank or 300 miles and that's using the thickest 20w50 oil I could find. It otherwise drove fine. Switch to high mileage oil or thicker oil if you haven't yet. I'm going to do the math as 7 hours x 80 mph = 560 miles. So you're burning about the same as my Tercel did.

Friends advised me to get it repaired before it breaks. Math said a quart of oil costs $1. Which equates ~$33 every 10000 miles or $333 for the next 100k miles. A valve job, engine rebuild, or whatever engine repair will exceed that easily. I seriously doubt I would put another 100k miles on it anyway. And I didn't. Car drove fine for many more thousands of miles. The only reason it didn't make it 200k miles was it was rear ended by a tail gater.

You can call it a bandaid if you like but I see no point in an expensive repair when it's such an easy and inexpensive fix.

 

Being a former auto mechanic, that sounds more like a leak than oil burning. Does it smoke when the engine runs? I have a 07 and a 09 with 150k and 200k that barely use any oil. What brand oil do you use? Try mobile 1 or castrol high mileage blend. I've had good results with both. Next changes will be exclusively mobile 1.

 

If you haven't already, thoroughly check for oil leaks around the engine. Otherwise switch up to a thicker, high mileage oil, with as high of a flash point as possible (higher flash point will result in burning less oil).

Some have reported that oil use went way down after running several tanks of fuel injector cleaner. This makes sense as burnt oil can gunk up the piston rings and create small gaps for oil to leak through. Injector cleaner would presumably help clean this up.

I'd go for a high mileage 10W-40 or even 20W-50 and run a few tanks with injector cleaner and see if there's improvement.

If you think you will go down the engine replacement route, it's better to do it now, as burning oil will clog up the catalytic converter. Otherwise you can run the car with it's oil burning problems until the cat clogs and sell it onward at that point.

 

Whatever you do, don't let the oil get more than a quart low (it only holds 4 qts as it is!). What will REALLY speed up deterioration is if you let the oil get low and wear out the piston rings, this has probably already been happening as you let it get low before you even knew there was a issue. No matter if it's leaking or burning, you have to keep it topped off with oil. I wouldn't let it get much lower than about half way between the two dots. Even just getting low one time will cause major wear and as the rings wear it will drink more and more oil. Or if it's leaking and you let it get low then it will start to drink more. Either way check the oil OFTEN and keep it topped off.

I know I just went on and on about something I could have said in one sentence but I'm trying to create a sense of dire importance. Two quarts low was killing your piston rings. You don't need to let that happen any more or it will be very dead very soon. As far as I'm concerned one quart is too low on a car that only holds 4 to start with.

 

What metric are we looking for that will tell us the flash point of oil?

 

Are you using Toyota bearings or just something cheap from a parts store? How many miles are you getting out of a wheel bearing? Is it always the same wheel or side having bearing issues or have you had to replace them all the way around? If it's always specific wheels then you may want to look at the hub and make sure it's not out of round.

Here is a pretty good article on various causes of wheel bearings, some obvious and some not so obvious.... AGCO Automotive Repair Service - Baton Rouge, LA - Detailed Auto Topics - Why Front Wheel Bearings Fail

 

Example for Mobil 1 0W-30 Advanced Fuel Economy:

 

I've driven Toyotas after they started burning oil and was successful (IMO) in maximizing their lives. Besides constantly checking the oil, the main thing I did was to slow down, especially on the highway.

There was another thread where a Prius was burning a lot of oil but the driver averaged 84 mph on his drives. That car has been getting worse with the oil burning and will probably continue to do so. If the OP can slow down on the interstate and hug the right lane, that would help extend the life. I realize that takes discipline but it's worth it.

 

Don't use B except for long downhill grades, that's all it is there for.