My problem with aftermarket injectors plus it hasn't been over 20 outside in a month iv been get 13-14 mpg. I'm guessing it because I'm running on stock mix with how cold it is. Plus the fact I always pre heat my truck never put it in drive until it's at at least 115. I feel with a custom tune I'll see alot better results from these injectors. I ran it with the race tune on edge for a week or two, I saw no less than 18mpg.