Bosch "Top 4" spark plugs worth it
I just fitted a set of Bosch "Top 4" spark plugs and new 8mm Bosch leads. At $55 a set the plugs aren't cheap, but I have noticed a small increase in power, especially in the top end. I don't know how much of this increase is due to the new leads. My old leads were 8mm Top Gun.
I would recommend these plugs for a quick bang-for-the-buck improvement in performance. Don't expect too much, but there is an improvement there if you want it.
QUESTION: Are these leads prone to crossfire if they cross at an angle? I tried to make all the leads run parallel and cross at 90 degrees where possible, to avoid crossfire. However I did notice a rough idle this morning which seemed to go away after a while.
If it ain't broke don't fix it.