So does anyone really know for sure if any of these performance chips really work or not? I have a 2010 4Runner Trail and getting avg mileage (18 to 19 city and 23 to 24 Hwy). I have a K&N cold air filter in the original cold air box. That has helped, but I still have hesitation when first stepping on the gas. My 07 Tundra 5.7 TRD never had this. I would love to have that power back, wishful thinking. Any suggestions on improving performance would be nice. I got rid of the OEM tires at 16,000 miles and put on the Kumho Road Venture SAT KL61. I run them at 32 PSI and they are running even on all four. They handle pretty nice for an AT tire even on sharp corners. I get good traction with them in rain and snow also.