I think this was posted before but I was curious if anyone tried the Autolite 3923 spark plugs and if they noticed better performance and gas mileage with them.

 

yep it was me. the only diference i noticed is the truck idles better. when sitting at a light every now and then i would fell the truck shake due to a funny detonation of spark. now it is like a smooth lake with no ripples. these are one heat range cooler then the stock champions. i have had no lose in mileage or power. a good plug and all 8 cost me 10.50 at walmart

 

I notice rough idling every once and a while not too often. I have 21400 miles now. I think when its time to change plugsI may try the autolites.

 

you will like them. even when its 110 outside

 

hey, when i was reading the application book, the 3923 models were the ones recommended for the V6 engine, and the 5224 spark plugs were recommended for the V8 engines...I went ahead and bought 8 of the autolite platinum 5224 sparkplugs. I have 6 changed out so far, will be doing the other 2 in the morning.

 

i wish you had read my other thread about the plats 5224. i lost between 45/50 miles to a tank of gas because of these plugs. so i did some research on other website and got the same answer. the 4.7 hates a plat. plug. they only like the stock champion or the 3922 / 3923 from autolite. these plugs are cooler in heat range. the plats are a hotter plug that just dont run correct in these trucks

 

Installed my Autolite 3923s on my '05 3.7yesterday. Jury is still out on any performance/mpg benefits but definitely much smoother idle. Suggestion for anybody thinking about DIY. Get a spark plug socket with a neoprene insert to hold the plug. That is a deep opening-you cannot get your fingers in there to guide the plug.

 

ok, well if these plugs do the same thing to my truck i'll return them and get the others.