I am in Montana this week for work and have an Impala Limited (old body style) for a rental car. As I was leaving town this afternoon I decided to stop by an O'Reilly's Auto Parts. As I was browsing I discovered that Gumout AIO was on sale for $5. As the Impala has just under 22k miles on it and it has probably been abused with many cold starts and short trips over its short life I figured I would treat it to a fuel system cleaner. Paid the $5, dumped it in, and hit the road. I had only put a few miles on it prior to adding the Gumout so I have no way of subjectively judging any improvement in idle, power, etc. On a side note, I am thoroughly impressed with the car's performance and handling (the interior styling...now that's another topic entirely). I have put a bit over 200 miles on it, most of it at 70 mph on predominantly flat roads plus some absent minded idling while BITOGing and have averaged a hair over 32 mpg per the onboard computer. Not too shabby for a fullsized American sedan. I believe this has the 3.6L DI V6 and 6 speed auto. It has plenty of pep and great passing ability. It doesn't come with traction control for nothing!