[Bigdav160]

<yawn> When I was a GM tech, almost 20 years ago,we routinely had trucks with 300k, 400k, 500k on the odometer. There was a lube place down the street that had a customer's truck featured in the local paper; over 1,000,000 miles without engine problems. GM just shrugged, nothing special.

Tighter fuel control certainly is a factor but the anecdotes above were throttle body injected. Overdrive transmissions help a lot with overall rpms turned. Oil has gotten better. Rigorous Maintenance is paramount and easy driving can't hurt.