Just got this little pump and so far only have one complaint. I have this mounted on a 45 gallon aluminum tank in my truck and this rascal is loud. Granted, it's on a smaller aluminum tank so that's part of the problem, but my Dad has a GPI  (silver pump) on a larger steel tank and it's so quiet you can barely hear it over his truck rumbling. I can't say that's a fair comparison since one is a large steel tank and one is small aluminum but I do believe GPI is a quieter pump. Other than that, this pump runs like a top and does the job I need it to do.