Believe me, I was surprised seeing that much improvements. I was not expecting anything, no improvement at all. I had re-checked my numbers. Btw, I would not do any grill block as the weather gets warmer, and when I am towing.
Sorry for probably an obvious question, but what is the reason for "Especially since the consensus seems to be that blocking the upper part of the grill is more effective than blocking the lower parts." ?
I blocked the bottom grill on mine for a couple reason:
1. Transmission cooling radiator is behind the top grill, but not behind the bottom grill. I did not want to risk heating the tranny. Engine radiator is behind both bottom and top grill, so it still receive some air when I blocked the bottom grill.
2. I figure the bottom grill will probably get more road debris and salt so blocking the bottom one makes sense.
3. The bottom grill was easier to block due to its shape
