The company behind Effuel has spent years testing the device under different conditions and situations to optimize it for most driving conditions in real-life. This means that whether you're in a cold area or are driving through the desert, you can rely on Effuel to save you loads of gas, and hence, money as well. In addition to that, the company behind Effuel also claims that the chip only alters the fuel efficiency of the car electronically so it does not change or hinder the engine in any way. All it does is increase your mileage and, if you're still not sure about the results, you can easily unplug it without any hassle.