[V8] Fuel injector cleaning

[Mark Kalbskopf]

What's the general wisdom on spending the $ to clean the fuel injectors?
I'm trying to solve a bad mpg problem, and I currently have the  
injectors out.
But $160 to $200 to find out that it really makes no difference is  
hard to swallow.
I guess mine are probably original with 190K miles.
But maybe all those premium gas fill-ups with detergent additives,  
cleans them out anyway?

Mark.