So... I've been running mobil 1 5w-20 synthetic since january anyway. Good for me. Apparantly I missed that in March, Toyota put out a TSIB that approved 5w-20 GF-4 oils for use on most of the older engine blocks.
Which is fine for me. A couple horsepower, easier pumping, better cold starts, no downside. Everyone else should pimp it.

Like always. Mobil oil's put out phenominal stats on Toyota v6's (and ofhand, everything else).

 

thats interesting.

i had accidentally put 5w20 into my car and freaked out about it, but hmmm i guess its ok.
i have a minor valve gasket leak so im using mobil1 syn 0w-40...

 

Be careful everyone. Look at the TSB carefully. Right up at the top, and again in the middle of the first page, it plainly says it's applicable only to the 06 and 07 model years. If your car is a 2005 model or older, this TSB does not apply to you.

The TSB is ambiguous because the engine family list contains blocks that are out of production. Do not be led astray by this error. Again, the TSB clearly says, 06 and 07 model years only.

Can't trust everything you find on the internet!!!

 

Good eye EK