Wow, lots of responses to the filter debate! I should note that I only use Honda brand filters on my vehicle and boat, no aftermarket brand. The Honda filters appear to be much better quality to aftermarket filters and again, appear identical for both autos and marine. I'm not too cheap to buy a good filter but if it's the same thing I might as well pay the cheaper price at the auto dealer. If anyone knows for sure they are different in any way I would welcome the info.