The tuner will NOT shorten the life of the engine. If you install a performance tune and do not put premium fuel in the car, that would cause engine problems like detonation, pinging, and possible head gasket or piston problems. So if you operate the engine within the parameters of the tuner you will have no problems. I installed a SCT tune in my 01' V-6 Mustang at 124K and the car now has 134K miles with no issues. In fact I am getting the best fuel mileage ever with the car. How can that cause the engine to have problems? It does not, period.