tacoma 4.0L spark plug change

I recently put new plugs in my 08 Tacoma, I used NGK iridium and set the gap to .40 and my mileage dropped approx. 3 to 4 miles per gallon. I have checked the air filter stock, tire pressure stock size tires, cleaned MAF sensor, added Lucas injector cleaner to 2 Tanks with NO improvement, any help will be greatly appreciated!!!

 

also its a 4.0L v 6

 

Ouch, put the old plugs back in, see what happens.

 

I would make sure all the cylinders are firing...

 

There have been some reports of poor performance due to the ir plugs, try putting a new copper set back in, or the orig, as someone already mentioned.

 

NGK irridium but wich number/model?

Where are you living? Winter blend naybe?

Winter tire?

 

Has your local weather changed dramatically colder? Colder weather always lowers MPG.

 

No winter tire, Atlanta Ga The plug is from Rock AUto
2008 TOYOTA TACOMA 4.0L V6
Ignition : Spark Plug


NGK 4904 {#ILFR6T11} Laser Iridium
.044

 

check to make sure you reconnected everything correctly. Some of those plastic connector things on the harness can become loose if you mess with them.

 

When I had my 4.6l Ford F150, I installed Iridium plugs. Ran smoother and got 1 mpg better gas milage.
When I installed Iridiums in my current 07 Tacoma with the 4.0, I lost 2 mpg.
The 4.0 just hates Iridium plugs. Reinstall new Denso copper plugs and most likely you will gain the mileage back.

Fritz

 

They come pregapped and really dont like to have gap changed.
Most likely gap is now to small for it. Believe or not, the bigger the gap with out misfire the better. And not an opposite.

 

use factory plugs

 

Other members have reported the same from those plugs in this thread https://www.tacomaworld.com/threads/how-to-spark-plug-change-1-gr-fe.30479/I would go back to the Denso stock plugs and see what happens.

 

Yep...I don't know why anyone wouldn't.

 

Shouldn't plugs that fit a 4Runner 4.0 be just as good for a Taco 4.0, same year??. [Confused]

 

Never heard of plugs making that much difference in mileage.
I guess the electronic engine management just doesn't play well with iridium.

 

did you gap your plugs?

 

Thread is over 5 years old.

OP hasn't been here since Dec of '15.

 

I am using NGK 1483, the platinum tipped ones, pregapped. G-Power Platinum Alloy Spark Plugs offer superior performance with improved fuel efficiency, lower emissions, and quicker starts. 0. 6mm laser welded fine Platinum tip reduces required voltage ensuring high durability and a consistently stable spark.

 

Factory plugs...