Was wondering if any other had tested this concept .most vehicule have a pass tru ground . From frame to head engine , tru the engine on the opposite side and to the battery it goes. So if wire are too close to engine metal everything is subtlely affected . By feel of things .i would say about 10%. On a radio 10 % difference between proper and improper is huge , on a flasher? A proper one pace is say 3.5 second , on improper its 3second(random value not actual ) I noticed change on engine , radio and flasher .slight rumblier engine exhaust tone (probably because the burn is more precise. Anyway , any have airgapped their electrical wire in some form or the other . I didn't bother too much with small wire(it's a drag .but I suspect everything in electrical need to be air gapped from any iron