Originally Posted by danez_yoda
There are not 0w-20 conventional motor oils. The Castrol GTX is likely a blend. Most SN+ rated conventional oils are blends nowadays even if they don't say it.
At 3-4K OCI (extreme conservative) when I'm sure the manual calls for 10K OCIs you could used the cheapest 0W20 you can find and the engine will go a million miles.
There is nothing magical about GTX. There are a few million mile toyotas and none of the owners said only this brand of oil could be used to make it this far. Thet just performed regular maintenance with approved oil.
If you are putting highway miles on it and changing that frequently (5K should be the shortest really) I would find a good promotion on Penzoil, QSUD, or Mobil 1 and load up at less than $10/ 5QT jug. Cheaper than conventional and better oil to boot. The new oil specifications coming out will cause a few clearances at Autozone and Advance Auto where you can pick up cheap. M1 frequently has $12 rebate / 5qt jug while walmart has it on rollback at $22. There was just a pricing anomaly at walmart (sometimes mirrored at Amazon) where people got 6 5qt jugs for $25. Plenty of deals.
I'm not a hoarder, but when a steller deal shows up I get 2 years worth of oil changes and never let my stash go higher than three years worth (6 jugs) Made me cry when the M1 deal showed up just after I had just hit my 6 jug limit with some Penzoil Ultra for $22 with a $22 rebate (free). Had to let it pass by and now seeing folks that got it showing off.
If you have the time to post this question to begin with and are clearly wandering around pondering or reading what type of oil to use then you have the time to find yourself some of these deals and get the best oil sold for almost zero cost. I currently have 13 fully sythetic 5 qrt jugs in my garage "purchased" only over the past 3 months on various deals listed here. I did not take advantage of every one listed just the ones I could get with minimal upfront cost or get delivered to me. If the issue is that you do not DIY oil changes, time to spend some effort either figuring that out or finding an independent shop that will let you walk your own oil in.