Recently I replaced the plugs and wires on my 99 5sp 4x4 v6. I put in Bosch Platinum plugs and a set of Napa wires. I definitely can notice a difference in response and how smooth it idles. However, I believe my MPG have dropped slightly, is this a possibility? I didnt change cap or rotor because i couldnt find an easy way to get to them and i didnt have my chiltons manual with me (its up at school). I also noticed a change in sound from my flowmaster 40, it now seems to be sounding a little more like a "rice getter". Anything I can do to make it sound deeper again?

 

get rid of the platnum plugs. i changed out my champions for the autolite 5422 platnums and lost between 45/50 miles to a tank of gas. went back to the champions and mileage went back up. something about mopar motors and platnum plugs

 

get rid of bosch plugs they work like **** in crysler/dodge get campions. Bosch are Crap no matter what vehicle you put them in.

 

mopars dont like the platinums but my ranger loved em. every car has certain querks and some parts work better in other vehicles. i run NGK iridiums in my dakota but bosch platinums are generally good plugs. in motorcycle applications champions are known to break inside the combustion chamber.

my point: EVERY manufacturer makes their fair share of crap but you shouldnt let that discourage you from the entire brand.

 

Bosch platinums did the same in mine, i swiched backto ngk's but not the iridiums.I should try those, im due for a tune-up.

 

I put in ngk v-power in mine and I couldn't be happier

 

i've been running autolite for the past 6 months i'm going to change back to champion when i put my headers on over the weekend. My truck has been sputtering a bit lately

 

if you get the iridiums on ebay they are like $2 a pop, i think its the same size one of the ricer cars take so theres lots on there.

 

hmm i have the bosch Plan +4 in mine with msd wires, and i lost about 1mpg.. you think if i switched out to iridiums that would solve it, the only reason i changed my plugs was becuase i was getting misfires, i was hoping the +4s would burn better and let me run a bit more lean till i get my TB, and i need a new MSD distributor..

you think if i want with iridiums they would be better then the plantiums, or should i just stick some mopar performance plugs back in there?

 

i second the ngk v-power.. good stuff... i put bosch platnium in my chrysler cirrus... she cooked them in 10 mins, its not worth putting in crap plugs into these trucks since its a bit of a chore to get to the plugs