I use it in the racecar helps with bearing life but that is with super hot oil, alcohol fuel, and babbit bearings. I don't see the need for street vehilces to have it.

 

i assume its the same as everything else in this world... used as directed it could work as intended with no sideeffects... used otherwise adverse results, who knows. then again anyone and everyone makes a better product than the last guy never had issues with lucas... but theres probably a good reason you dunt run lucas in your lawn mower... most lawnmowers use a peg to splash oil around to lubricate things. lucas probably makes it too thick and you'd toast your 7.5 hp engine anyways hahaha