Ive made a little bit of progress. I was hoping to do more but we are forecast to have a big storm come through in a few hours so Id rather not start something I can't finish.
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Before I started with the grille block. The nice people at Mazda already put in a nice partial block. It really isn't very substantial.
After I applied a liberal amount of black duct tape. Im doing this the ghetto way! If I was going to actually make a block for the inside of the grille I would have to take apart a lot of the front end
Im thinking of rounding off these bad lads with painters tape covered in silver shiny tape. I never use these lights anyways, they don't make much of a difference.
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I attempted a bidirectional test using a 55mph stretch of highway and my cruise control. I set the cruise control, reset my factory installed mpg gauge at the same spot on the highway and went for an exactly one mile drive.
Before the grille block: 39.8 average
After the grille block: 45.6 average
... these numbers can't be right. I did close off a huge area but it's like giving Michael Phelps orthodontics to fix his overbite, sure it will help performance but by how much?