Spark plugs

What plugs best recommended for 2009 4.0

 

I would go with OEM. Toyota Part number is 9091901235. Some have reported issues when going over to an iridium plug. Change every 30,000 and forget about it.

 

Stock Denso K20HR-U11 or

$6 NGK LFR6C11 NGK (7787) LFR6C-11 V-Power Spark Plug, Pack of 1

NGK LFR6C11

 

I'm about to change mine out as well and just waffling between good ole copper/nickel and platinum. What the heck is this "Ruthenium" all about?

 

Denso K20HR-U11

 

If I told the chances are good that the old copper core has the potential to go 200K+ miles.
Would you believe?

Would you believe me if I told you it’s a known fact the copper core can go well over 100k?
Would that help you choose what plugs to use?

Should you go that long between changing the plugs? No, not at all.
But the evidence shows that copper core aren’t a bad choice.

 

Same. Go OEM….. They work perfectly fine. Although I go more than 30k between changes.

 

Yeah I am sure its fine to go over. I did my first swap at 45,000 and 11 years just because. Plugs looked fine and no differences I could tell.

 

My manual states that the 30K change, “Applies to Tacoma with 1GR-FE. Required under the terms of the Emission Control Warranty.”

Again, I’m not advocating to go longer. As I’m sure there is some degradation to the emissions system the longer you wait. But…….

An No, I didn’t change mine at 30k.
I didn’t know I was supposed to, because I didn’t read the maintenance guide.
I joined TacomaWorld and found out

 

I wouldn't have done it if they weren't so cheap and so old. Was surprised with how good they looked so I'll probably push out the next one again.

 

And for some weird reason I can get the factory plugs cheaper at the dealership than any store or online. I get a set of plugs and the diffs and transfer case gaskets at the dealership every 30k.

 

I have no intentions of doing them before 50k, ever.
Not unless I have an issue that calls for it.

I may be active on TacomaWorld, and I do try to help with technical questions.
But I don’t enjoy working on vehicles. The only reason I work on them, is to save myself or others money.

 

I see you around all the time helping out and we all appreciate it. I am a mechanic so even though I enjoy working on cars. I don't like spending my free time working on maintenance like stuff. Rest assured it gets done eventually but maybe procrastinate a little bit. Oil changes are always right on time though.

 

Oil is changed at or before 5k.
Differentials somewhere between 30k-50k.

Type and brand doesn’t really matter to me.
What matters is, that there is some in there

 

Marketing

I've seen incorrect spark plug applications cause random misfires and codes and knock modules off the can/bus network. One customer actually got rid if a perfectly fine vehicle because a previous tech used the wrong plugs. It kept randomly stalling, setting p0300 and network communication codes. He traded it in before we could figure it out. I heard later from the dealership tech they fixed it with oem plugs. The "noise" from the coil field collapsing was backfeeding into the entire vehicle harness, randomly knocking modules offline

The engineers designed the ignition system to operate with plugs from a specific heat and resistance range. Unless you're building a race car, stay with oem

 

I'm sticking with OEM, makes sense... I'm having great success with Rock Auto for finding and ordering parts, better pricing that anything local or dealership here in my area. This is a good forum to learn stuff and things on, appreciate the comments!

 

Denso k20-hur11 on both banks. The 4.0 likes the hotter burning copper. Some change to iridium with no ill effects though.

 

I actually went 125k on my last set.... I severely neglected my spark plugs while doing all of the other major maintenance. The biggest issue that merited a spark plug change was that I was getting 150 miles to a tank and sluggish performance.

The gap was .061-.063 after I pulled them.

 

I'm curious as to what mine look like as well with the mileage I have on 'em... Not noticing any issues with performance/power or gas mileage, but once I change 'em out, I'll gladly share a "yes, change your plugs regularly" and/or post what my new experience is and a photo as well. Thanks for sharing that photo!

 

It wasn't too bad of a drop off in performance but just enough for me to notice. It definitely helps that I changed them out though, my truck idled completely different afterwards lol but I'm sure that's how it supposed to be anyways.. yep, always change your plugs and check your gaps haha