Can you extend drain intervals without practicing oil analysis?

It's a roll of the dice. You can, but its risky. As the old Fram filter commercial cautioned: "You can pay me now or you can pay me later" when unscheduled downtime arrives.

Extending drain intervals without practicing a disciplined oil analysis program is potentially hazardous to your equipments health and your reliability goals. The savings on oil can vanish in an instant if you're not monitoring the condition of your oil in your asset as you try to stretch the time between scheduled oil changes..