I have a 06 Frontier XE 4cyl 5 speed. I have seen a little bit about the 2 degree timing advance. I would just like to know how much difference others have noticed who have had it done, and if it is worth doing. I live in a small town that has a Chevrolet and Ford dealership. Would they have the programmer to do it, or will I have to take it to a Nissan dealer? I was also thinking about a leveling kit. Not really a lift kit. I would just like to lift the front to make it level and look a little better. If anyone could give me some advice about how much and is it the best way to go, that would be great. I would also like to know how it would effect my mpg. I know that bigger tires will decrease it a little but I am not sure. I am running just the regular 235 tires on it now. If I get a leveling kit I would like to put some slightly bigger tires. I was thinking of 31s or 30s but what is the best? If there is any other things I can get to receive some more horsepower or mpg, please let me know. Thanks for your time. By the way if any one has put a leveling kit on a frontier like I have I would really like to see a picture if possible. Thanks Again!