Is your truck getting the most out of its oil?

TORONTO, Ont. -- The last truck I owned was a 1991 Peterbilt 379 with a Detroit Series 60 engine. I had to change the oil in that thing every 10,000 miles (16,000 km). At about $200 a pop every time I pulled the drain plug, oil changes took a significant bite out of my maintenance budget. I'm not in a big hurry to buy another truck, but I have to say I'm envious of current truck owners who can get away with two or three oil changes per year -- in some cases, maybe only one.