I Always Use 93 When Available.
I have a big stupid truck that I could probably run crude oil through and it would fire, but I run 93 in that also.
I also use full synthetic oils, and maintain oil and air filters,...
I even change cabin air filters in my cages,...Oh, and I change the filter in my HVAC in the house every 30 days too.
Say what you will, but I have never a bad valve, thrown a rod, had a vehicle blow blue smoke, never needed a head gasket rebuilt, never needed an injector cleaned/replaced,....ever (knock on wood). I drove a Ford Escort (Mazda engine) to 250k miles using full synth oil (from first 500 mile change) and highest quality fuel I could find. After seven years I finally decided to trade it in for a six pack of beer and a bag of Snyders Pretzels. You couldn't even feel it at idle in the driveway, the engine still ran like new. The clutch however needed a little loving,...I always tried to drive it like a Porsch. Haha!
I'm not saying I'm Mr. Goodwrench either, far from it. Its just my opinion that if you take good care of something, and use your technology where you can, the 'something' will generally take good care of you back. I understand the whole "But Pete, the book says,...!!!" Ok, ok,... I get it, haha!
Dang this sounds preachy,...not supposed to be,...sorry, as you were,...

ray: