OK, here is my opinion, like it or not. Probably going to ruffle a few feathers. Race application, worth the money. Street application, waste of money. Being a GM Technician, I can tell you, they cause problems. First case-the oil from the filter, if it's properly oiled,(and it must be to work properly) can get into the Mass Airflow Sensor and cause false readings affecting performance and fuel mileage, not to mention it could turn on the Check Engine Light. Second case-it is allowing more airflow in, in turn, the computer sees more airflow and in response adds more fuel. Better fuel mileage? I think not. Yes it would breathe better, but the bigger the breath, the bigger the shot of fuel. Third case-I have seen cases where the cold air intake setup you talked about on your S-10 moaned so bad under heavy throttle, the Knock Sensor thought the engine was spark knocking and retarded the ignition timing causing the truck to fall on it's face. Fourth, a four cylinder S-10 is not going to have any kind of noticeable performance increase from an air filter or muffler. You still have the same sized exhaust pipe coming off the engine and the same sized tailpipe going out. It is only going to flow what will go throught the smallest point of the exhaust system. It definately didn't gain 3-6 HP. And before you start saying I don't know what I'm talking about, I have been a GM Technician for 17 years and I have seen all of this in real life. And I also have a 4 cylinder S-10, it is a slug and always will be.