Range Technology Performance Chips

I'd rate this product a strong 2 to weak 3 star overall. It seemed to work the way intended as long as you were under 55 mph. At highway speeds, it didn't seem to make any difference at all, which is where I'd hoped for improving my mpg. When it was engaged, the 4 cylinder mode sounded different than factory 4 cylinder mode & the transmission seemed a bit choppier on shifts. After about 10 days use primarily in city driving, my wife noticed that the vehicle started to die randomly at stop lights or when stuck in non-moving traffic. That's when I decided it was no longer worth any city driving savings on gas, as safety is more important. I rated it the way I did because when it did work in the city, it definitely increased mpg. Maybe I got a lemon off the line, but not worth risking the safety of my family to find out.