I have a 99 Chevy Tahoe 4X4 with the 5.7 motor. I do lot's of highway driving pulling a boat trailer. I have AMSOIL 5-30 in it now. I know this is the weight they spec when it's new, but it has 110 k on it now. I live in Sacramento CA so Heat is a factor, Cold is not. I drive alot so 6 month OCI would be great. Does it make sense to change the filter more often than that? Thanks for your input.