2014 Silverado 4x4, 93K miles. 5.3L. Still does over 20 MPG highway. Fuel management system works fine. No major issues beyond a new A/C condenser last year (at dealer, $350) Engine has always been noisy, due to what they call a "high pressure oil system" and 0W20 synthetic pizz for motor oil.
Oil and filter every 5K miles since new. Been over 20 years since I had a truck with this much mileage, as I was on an every four year swap cycle. Too old and too poor for that now.
