What is the difference between the XG and XP Series Generators? The XP Series features Generac\'s TruePower Technology that is < 5% total harmonic distortion and a 3 Year Warranty. The XG Series does not offer TruePower Technology. Harmonic may be >5 total harmonic distortion. The XG Warranty is 2 years. The XP Series includes several features that make it a more premium, contractor grade model, including idle control, an integrated lifting eye, full panel GFCI protected outlets, and a 3 year limited warranty. The XG Series is designed for residential applications, with the PowerBar that monitors available wattage and a 2 year limited warranty.