[BioStroker]

I've been running Valvoline Premium Blue Extreme 5w40 for about 4,000 miles now, and am have a couple of questions I'm hoping to get some opinions on.

1. What kind of change intervals should I go with a synthetic? The guy at Carquest told me I could go 10,000 miles if I just change the filter at 5,000 miles and top off the oil. That sounds high to me, I'm used to every 3,000 miles on dino in a gasser.

2. Is there any reason not to change from synthetic back to dino? The synthetic is expensive, but if I can SAFELY go longer with the change intervals I can see it being worth it. I don't have a bypass oil filter. If not, I'm probably going to switch back to dino. Does it hurt your engine to alternate between synthetic and dino?

3. What's the best dino oil and how long is everybody going between oil changes on dino?

Thanks! If there's anything else I might have missed please feel free to comment.