Burning oil at same rate regardless of oil thickness --- What does it tell us?

I thought you had already bought Auto-RX
Did you try it yet?

My oil consumption is down to 1qt per 5,000mi using ARX maintenance doses...

 

I still stand by my previous recommendation

Use ARX at full dose initially and reduce to maintenance doses when consumption drops to acceptable levels

 

Refresh my memory. How bad was your initial consumption and for how long?

 

See my original post:
One for the Experts - Only (Oil usage)

 

At $25 per bottle, I recommend keeping it in there for 10,000 miles by using the group3 synthetic

 

Keep in mind he will go through 13 qts of oil in 10,000 miles. Hardly any additive will be left by the end.

 

Thanks for the link. Here is what I think about your issue. Your oil consumption was not caused by dirty/worn out rings, but rather oil type change. It's not unusual to experience sudden oil consumption when using new oil type that goes away on 2nd or 3rd interval with the new oil. You description sounds exactly like that. The causes for that are unknown, but it's speculated new oil with different chemistry disturbs a balance between rings/cylinderd and oil will be consumed till new equilibrium develops.

 

I understand the theory, but don't necessarily agree with it

If switching to synthetic were the cause in these cases, everyone switching back to Dino with all kinds of treatments should immediately cure them

In any case, my consumption is still decreasing although I would have been happy with the initial results at 1qt per 3,000mi

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AllenZ would be consuming the 13qts whether he was treating or not
Actually, by changing Dino at 3,000, he would be wasting 2qts with each of the 3 changes

AllenZ - Please keep us posted on your methods and results

 

What oil are you using?
Keep it topped off and continue treatment

 

It's fine to use regular (non synth) oil, but do stick to a reputable brand. Never use "off brand" gas station of "dollar store" oils. PQIA (The Petroleum Quality Institute of America) has tested some and found them to be very substandard and definitely damaging to an engine.

 

That would be "SuperTech" oil. That's like a Wallmart home brand, but it's an ok oil. That stuff will be "homebranded" from one of the larger legitimate oil distributors.

Most of the really bad oils that PQIA uncovers are usually small fraudulent oil distributors selling at small discount stores and gas stations. Some of the bad brands they've uncovered are "Super XXX", "Bullseye", "Everclear", "Orbit" and "Maxiguard".

 

By the way how do you evaluate amount of oil burned in quarts? I mean I could top it off and see how much is left in quart jug, but does anyone have an idea how much is between MIN and MAX marks? Mine Prius 2009 with 60k burned about 1/3 inch from MAX mark down. Is that much?

We have moved to Seattle area recently (winter cross-country on Prius was awesome) and here I have to enter the highway uphill on my daily commute, so I guess it is hard on such a small engine. At least every day I'm driving that location I feel the smell of burned oil. I guess it is hard not only for Prius.

Do high RPM affects oil burning? Or engine wear? Will synthetic oil reduce engine wear on high RPM?

 

Addition to the previous message: 1/3 inch in 5k. I guess the smell of buried oil is from other cars running almost full throttle on that part of the road.

 

That 1/3" down would only correspond to only about 0.3 quarts, so that's pretty good for 5k miles. That's about what I go through every 2k to 2.5k miles btw (2005 model at 135k miles).

It will definitely help if you make sure that the engine has a few minutes (minimum) to warm up minimum before doing that.