Actually the 3.6L LFX DOHC Variable Valve Timing Direct Injection engine replaces the 3.5L that replaced the 3.4L that replaced the 3.2L that replaced the.. well you get the idea. Before the 3.6, a few Impalas had the 3.8L Buick engines. I had one of them.
The 4.3L was used in some S10's and the full sized Chevy pickups. My 2009 Silverado had a 4.3L. We've owned about 5 Impalas since 2000. We'll probably have the 2013 until we die. (And I get as good mileage driving the Impala as Sharon does. I'm not too sure that it doesn't do better if you put a little foot in it.
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