I didn't pass MD inspection so I decided to do a major tune up on everything. I thought that I should do something for my injectors and a little shaky idle. picked up a bottle of Gumout fuel injector cleaner. I gotta say my Idle improved, steering wheel vibration went down and def feel a little more throtle response. Gas milage went through the roof too. I use to get 21 average now I am thinking Im going to get around 25, pretty much same driving style as before, mix of heavy traffic and highway. for 4 bucks, it's an inexpensive and easy maintance option, so give it a try if you have a higher mileage vehicle, hope it helps.