Sorry for posting again but had to comment.. "Energy Conserving" oils specifically simply should not be used.. The majority of off-the-shelf oils now must meet this qualification and will continue to achieve this goal for lessened regulation and attention from the population.. it is not for the benefit of the consumer... If I am not mistaken all of M1 conforms to this standard, with the exception of M1 0w40..
Never heard of a single one, Rob. Even to the point that, if memory serves me correctly, we've seen many Blackstone reports specifically state that the 2UZ is one of the 'easiest on the oil' engines that they regularly test.
I am doing 5K mile oil changes with kendal synthetic blend, came across a deal that I couldn't pass, oil came in a 15gal barrel so dispensing is not that easy but for the price, I am willing to deal with a few inconveniences