Opting for the 2006 Chevrolet Impala SS over the LTZ gets you more horsepower, as in 303 from the 5.3-liter V8 vs. the 240 horsepower from the LTZ’s 3.9-liter V6. However, there is a downside. Choosing the Impala SS means losing many of the LTZ’s nicer standard features. For instance, the bucket seats in the SS model are clad in cloth instead of leather, and you lose the LTZ’s seat heaters and the passenger’s seat power adjustment. Pay more, get less? Well, there is that big V8, as well as other hardware upgrades. And the SS can be outfitted like the LTZ if you’re willing to pony up the cash.