Engine oil loss...

U could try some 5W30 high mileage oil on your next change and see if that helps. I use 10w40 in my Camry and it doesn't burn a drop in 5k oil changes.

 

1.5 qts in 5k miles is not worth the time to look for. Many new engines will use that much or more. I think the factories usually figure that 1 qt in 600 miles is still acceptable. However, if you need something to look for, check the emissions items like PCV and other related item like this.

 

That is pretty normal. Although I didn't see noticeable oil consumption until 150k. It now has 237k. It burns about 1.5qt every 5k, which is actually pretty good. I have used Mobile 1 full synthetic since day one.

 

It's a good deal of oil consumption but not enough to exhibit any tell tale signs. You could burn up that amount through the tail pipe and not notice a thing. I'd start using thicker oil like 5w30 as suggested and see how much is burned next 5k miles. And move up from there until you no longer need to top up.

I had a 1992 Tercel that burned a quart every 300 miles. It was a couple thousand $ for an engine rebuild or add a $2 quart of the thickest oil available. Guess which one I chose to do?

 

My '08 started using a little when I passed the 110K mark. Car is routinely driven at highway speeds, which tends to cause it to use more oil anyway. I tried a couple of changes of synthetic to see if mpg might improve. Decided even with an extended change period that it wasn't worth the extra cost. I switched to a high mileage 5W30 three changes ago now, and it appears that the engine is using less oil. Consumption on the last change was just under a quart in 5K. The manufacturer claims their additives will soften up valve guide seals and clean the oil control rings on the pistons. I just might believe them based on this evidence. I do an oil change every two months with all the driving I do, so I will continue to keep track of this "improvement".

 

What brand high mileage oil did you use AxWxGuy? I had fairly good luck with valvoline maxlife on my last oil burner.

 

This oil consumption is not unusual given your odometer reading. The reason for the oil consumption may be due to slightly worn piston rings or valve guides. Don't worry about it, just add oil as needed to keep the dipstick oil level comfortably above the lower dimple.

To provide another data point, my 2004 with 147K miles uses ~ 0.75 quarts in 5K miles. I observe 7.5K mile change intervals with full-synthetic 5W-30. I recently added some oil to bring the dipstick level back near the top dimple, as I will be changing the oil after another 2.5K miles.

 

Yes, that is the brand. In the red bottle.

 

Kumar,

As others have posted your Burn is not all that unusual and this site has a lot of posts about Prii over 100K startign to burn some oil with no visible signs. My Ema is burning a quart of Pennzoil high mileage 5W-30 every 1500 miles or so.

Some others have had some success limiting the Burn with high mileage oil as stated here or some type of additive that helps clean/restore the engine. These include: SeaFoam, MMO, Restore, Liqu-Moly, etc... Personally I have not had success with any of them and am going to try Pennzoil high mileage 10W-40 at Emas next oil change.

This is the link to what I think is the best thread on oil burning:

2008 Prius - burning oil at 135,000 miles | PriusChat

I hope this helps.

Chris