tacoma 4.0L spark plug change

denso on one side, NGK on the other?

 

Does anyone else have any issues or feedback on iridium plugs, while this thread is revived? I wanted to get a set for my truck but don't want to if it will negatively affect it. Thoughts?

 

the premium plugs won't cause any particular harm, but at 30k change intervals, you are not going to take advantage of their superior life. The last time I ordered plugs, in November, Rock Auto made the recommendation to use change out the boots and seals at the end of the stick coil. That, along with new plugs at 35k (I got lazy and waited an extra 5k miles to change, when they should really go 60k) made the truck run a bit smoother. The new boots are good idea,
NGK 59009 Spark Plug / Coil-On-Plug Boot $ 4.06

 

Just use the spec copper plugs and forget about it. You can usually run them longer than 30k without any ill effects. 40-60k on the OEM coppers shouldn’t be a big deal with an otherwise healthy engine.

 

I tried iridium (Denso) in my 2014 v6. Lost 2-3 MPG. Closed the gap, no difference. Opened the gap, no difference. Six months of playing with the plugs I want back to stock platinum Denso’s. Got my MPG back. YMMV

 

I was thought you're not supposed to gap iridium because you mess up the tips rendering them useless

 

Wow. This should be a PSA given the price difference. I don't understand why but that's a completely unacceptable result...

 

Just go with Cu OEM plugs.

I ran Iridium from 30k to 60k with no issues, but I did notice a bit of an mpg bump when going back to Copper.

 

The 4.0 was not designed for iridium plugs. Use the OEM NGK plugs, and either swap or check them every 30,000. If you go over 30,000, your gap will be out of spec. You won't feel that until it gets way bad with these trucks, but the coils work harder and harder to push that spark as the gap widens.

 

I ran iridium plugs for 50k miles in a 06 X Runner ran great. Who cares about gas mileage when you drive an X you got your foot in it, at least I did. it still had those when I sold it last summer.

 

Yep, go back to Copper, unless you are supercharged. I experienced this for myself. Somehow, the truck/stock v6 runs hotter/richer with iridium spark plugs. I lost around 3 mpgs when I installed irridium plugs and have been running copper since then.

 

Your gap will likely be just fine even if you go 60-80k. I’ve seen it several times.

30k is still a good idea.

 

Well, I've done my plugs 5 times now. I carefully set them at mid range and at 30,000 they are always at the top of the of the range or a thou or two over. I save one representative plug from every change out as a record. Maybe it varies by truck, but mine is very consistent.