Review on 🔌 Lisle 67800 Spark Plug Gap Adjuster for Optimized Engine Performance by Chad Carter

Like many other reviewers, I noticed a lack of precision in the resulting tool. In some cases it differs by as much as 0.005 inch and for a spark plug that is a lot. Not to mention the technical aspect, an improperly spaced spark plug can cause problems ranging from poor gas mileage to coil pack damage. The worst case scenario would be a failure of the ignition coil driver in the PCM. This bug will easily set you back $600 and it's cheap. Bottom line: I wouldn't recommend this product unless you have a caliper to check the true readings in that position. I have one and that's the only reason it gets 2 stars. Although I can understand all the 1 star reviews.