Poor gas mileage.
Poor gas mileage. I purchased a premium chip in March 2021 for my 2008 Toyota Tundra with the 4.7 V8. I had previously installed another chip that gave me 1 MPG. Up from 14.5 to 15.5 MPG. Instructions provided stated "No need to remove other chips." MPG went to 18.5 MPG. Not what was advertised but a good increase. I reasoned after a few more miles it might climb more. At about 500 miles MPG started to fall. It got as low as 12.5 MPG. I removed the other chip. Now 2000 miles after purchasing the premium chip my MPG is back to 15.4 MPG driving locally. If I go somewhere on the interstate, it drops about 1 MPG. It would appear I paid a lot of money to get nothing.