Not even sure I am getting the power or fuel economy advertised. The real issue for me was the half ass instructions provided. I used a lot of common sense to bypass the frustration caused by their instructions. The biggest issue was the time it took to figure out how to get the air filter on within the air box. I used WD40 to lubricate the edges, after fighting it for a good 40 minutes. Later read others cut their filters. I don't recommend that. Overall the jury is still out on this.