oliveoil
I'd say that on average I add a quart of oil every 8-10k miles. It varies due to some long runs I make. Depending on where I travel its not uncommon to drive 12-18 hrs straight. Drive W on I-80 and a 20-35 mph headwind is common. I planned on doing a uoa @ 60k miles, but I'm planning a trip to SE Alaska via Seattle next month which is approx 7k miles. I wanted to be sure my oil had enough TBN to get me home. When I get home I'll replace the Bypass Filter which holds 2 quarts. Per A310, I'll check my bypass filter on the road and determine if it's working by feeling how Hot it is.