The 5.3-liter flex-fuel engine in our test Tahoe musters a respectable 320 horsepower and 340 lb.-ft. of torque. Floor it and you get acceptable acceleration, and there’s enough grunt down low to keep you pretty satisfied, but the problem is the old-school four-speed automatic. Though once four speeds were plenty, today Chevy’s lagging behind the five and six speeds of other manufacturers; a six-speed is coming, and it can’t happen too soon. The transmission is slow to downshift, and when it does, it’s with more lurching than today’s standards allow. Although this V8 features GM’s active cylinder management, which shuts down half the cylinders under light throttle and deceleration, we still recorded lousy economy of only 13.3 mpg.