Too often trucks come into our shop experincing high EGT's, turbo lag, excessive smoke output, and bad fuel mileage which are all symptoms of a boost leak. It is so common to develop a boost leak that we now require all trucks to have a leak down test done prior to strapping them down on the dyno. What's funny is, most truck owners that we do identify boost leaks on never even knew they had one. The reality is that even if you can hit peak boost, you may have a leak, especially if you have a variable vane turbo. Variable vane turbos will change vane position and other operations to try to compensate for the reduced level of boost pressure in the intake system. Leaving you driving around without an idea that your turbo efficiency has taken a hit.