Florida8L

Just put in a fresh set of 4 prong NGK 3911 plugs on Saturday and have logged about 350 miles so far. Wow, what an improvement over the Bosch $22/plug 4 prong units that have been in there for about 30K before me. The NGK is platinum laser cut with a corrosion resistant (silver color) metal body.


Smooth idle, unlimited highway power, car leaps much better from a rest. I can't imagine what the bosch would look like at 60K miles which was the service interval Im told.

to change - 25 torex to remove 2 loom brackets screws. be very careful to not drop them, as they are not friction held in in harness. a small screwdriver inserted into the top/back of clip and they all are removed and inserted back into holder together. on torquing the plugs they seemed to fully collapse the gasket at 1/4 turn so I didn't go the whole 1/2-2/3 as shown on the box - but 1/4 and then 1/16+. it's a feel thing - because it's an aluminum head. I put anti seize on each plug too, because of the dis-similar metals concept and light corrosion in 2 tubes. I sprayed each coil rubber part with a shot of fresh silicone and recoated them. each popped back on properly. was a great success. Dealer was recommending iridium single prongs for $13 each. The NGKs were $8/each and bennett auto in Pompano Beach on a wholesale discount. I think they are about $13/ea at the dealer.

NGK laser platinum 3911 on left, dealer bosch on right.