Originally Posted By: researcher
Originally Posted By: crazy_raccoon
lol.. it's like the lawyers were talking trying to cover their rear and by covering all the options, they didn't choose any at all. too funny! Thanks Gokhan for posting that, I'm sitting here laughing at that!
I feel sorry for the people who actually try to follow the manufacturer's recommendations when reading the owner's manual. They're going to be very confused! wow.. lol
[censored] yeah I was too! We might as well go back to at least 5W-30 instead. Funny thing in the Scion community is that '06 and before owners barely reported oil consumption issues and those of us with '07 and after, the reports spiked tremendously. There was even a guy who owned two tC's. One spec'd for 5W-30 and the other 5W-20. Guess which one burned oil and guess which one didn't?
Right, I see your point. I actually have one of the 06 scion tC's that could use 5w20 or 5w30. The real reason for the 06 being back spec'd for 5w20 was the high rate of failures of journal bearings in the crankshaft for the 05 model year. I did use 5w20 on my 06 tC (2az-fe engine) but it didn't feel right (felt "thin"). I switched back to 5w30 and that felt good. yes I know I'm using my butt dyno, so to speak.
What I will say is that I've seen the 2az-fe engine (for 2006) is a HOT engine. I did some research and found that Toyota had a bunch of sludge-prone engines. Anyone can search this on the internet. I think when it came to my engine they made it run hotter, quicker, to eliminate the issue of sludging. Yes I know there are many factors to sludging but I'm being simple here. What I found was if the NOACK is above 13% the tC engine WILL consume oil. It makes sense because it's one hot engine. Not that it's above 190degrees it's how quick it gets there. I can have boiling hot heat from the hvac in single digit degree weather! That shows me an engine that heats up QUICKLY!
Yes I know there's more factors but I found that keeping NOACK under 13%, it doesn't burn any oil, but it's not burning it in my case, it's vaporizing it into the pcv system!
For the other people 07+ who have true oil burning. That isn't just because of the 5w20 oil (probably didn't help), it's because Toyota decided to go with low-tension piston rings! There's a not-so-good idea.. For the lucky who have had those low-tension rings replaced, I've heard the oil consumption stops. Makes sense.
I had to tell everyone the rest of what you're referring to, it's not just because of 5w20 oil.
