2012, 5.7 Big Horn. I been blaming a drop in fuel mileage, about 2 mpg on winter fuel, although I never noticed it before. 32,000 miles, i guess time for plugs to be changed. Don't notice any differance in performance but could the plugs be the reason? Also thinking on putting in the best plugs, 100,000 miles. Opinions please.

 

You wait till around 45,000 miles . I i run platnium plugs in my 09.. runs great ... 202,754 on the clock...

 

Sounds great to me. Kinda scared of breaking one so probably will let dealer do it. Thanks a lot caps.

 

My 06 said plugs at 30,000 miles and my 14 says every 100,000 miles. What does your owners manual say. My 06 went 50,000 miles on the coppers and still looked new, then changed to autolite double platinums for the next 65,000 miles and were still in it when I sold it, and running great. I wouldn't be in a big hurry to change plugs, especially if you're having the dealer do it. You can buy a lot of gas for what they are going to charge you. If you do it yourself, go for it, but I think you will find at 32,000 miles they will still look new and you've wasted your time and money. JMO


Also the winter and the winter fuel is probably why you're down 2 mpg, and this has been the worst winter we have had in many years

 

does anyone know why the 14s went to 100k miles. What spark plug do they use?

 

Was told the factory plugs in my 2012 are the cheap $3. Something plugs, henve recommend 30,000 miles. There are 100,000 mile plugs avail at around $7. Something each. With 16 plugs you're talking a big differance.
I've been told its easy to break them, thats the only reason I was thinking dealer. Probably will wait a while and see what it does when the " summer" fuel comes out. weatherbise, I doubtnthats much of a factor here in FL.

 

I've done the plugs on my '09 twice, once at 30 and once at 60k mostly for the lifetime power train warranty, in each case the plugs looked new (I've kept them as proof along with the receipts). The labor is not that hard, just tedious. If I can put in the 100k ones at 90k miles, then I will. I just need the part number.

 

If you just hit 32k, I doubt it's the plugs affecting your mileage, unless you drive hard. I did my '08 and my '11 both right near 32k and the plugs looked great. Probably could have gone to 50k easy. Also, I did a lot of reading up before I undertook the task myself and never saw anything about breaking plugs. It's a little tricky for the back couple plugs if you don't have the right sized deep socket, but the job is definitely worth saving yourself the $350 the dealer is gonna charge. You can get the plugs on Rock Auto for about $60.

 

X2. I have changed my own plugs also. The back two on each side are harder but nothing that anyone with the right socket and extensions, cant do. I also see no reasoning behind the, they break easily statement. Just use anti-sieze on the threads, put the plug in the socket and slide it down the hole using two extensions. In the back two, start the plug down the hole using one extension, then as it gets in deeper add the second extension and it will make it to the bottom. The reason for doing this is a long extension with socket and plug may not go in the hole straight, and may hit obstacles and jam up before getting all the way in, but only on the back two plugs on each side. The others will go in with a longer extension since there are less obstacles above the holes