I have used nothing but Penzoil 5W-20 (conventional) and Toyota OEM oil filters in both our 2009 Vibe GTs since we bought them new in 2009 and have had no issues whatsoever i.e. so far, they aren't using any oil.
I started out doing an oil change every 2500 miles because the oil seemed dirty at this point, so I figured every 2500 miles would keep with the 5000 mile interval stated in the owner's manual and it wouldn't hurt putting fresh oil in more often. Last year I sent samples of the oil from both our Vibes to Blackstone and they said we could safely go 5000-6000 miles between oil changes. The Vibes are both due for their next oil change in a little less than 1000 miles (50,000 miles). This will be the first oil change that has gone 5000 miles, so I will be sending another sample from each Vibe to Blackstone to make sure everything's looking good, but I'm not worried.
As others said, I don't think using synthetic or conventional oil really matters as much as regular maintenance in general does. My dad's 2001 s10 is currently at 298,xxx miles (all put on by him) and he's never used anything other than Penzoil 5W-30 conventional in it. We had a 1989 Pontiac Sunbird that had 300,000+ miles on it when my dad wrecked it in 1997 and again, it was only ever fed Penzoil 5W-30 conventional. We also had a 1994 Pontiac Sunbird that had 268,010 miles on it when we sold it to a junkyard in January of 2013. It still ran great, but was
really rusted which is why we decided to let it go. It too only ever had Penzoil 5W-30 conventional. The mechanic that we used to go to had to change the head gasket on the 1994 Sunbird one time. He was always giving my dad a hard time about using Penzoil. Once he got a look at the inside of the engine, he never uttered another negative thing about Penzoil
. All these vehicles always had their routine maintenance done on time and I know that is truly the thing that has given us so many miles out of all of them.
On a bit of a side note, this thread reminded me that I need to head over to TRD Sparks and order a 10 pack of Toyota oil filters
!