Spark Plugs Every 30K Necessary?

I have a 2007 double cab 4x4 4.0L engine . The service manual calls for new spark plugs every 30k miles. I changed them at 30K using 3 NGKs and 3 Densos and saw no difference in performance or gas mileage. Now at 70k miles I am overdue. Gas mileage ( 19 mpg average ) and performance are no different than at 30K. Aside from keeping the emissions warranty in effect, why change plugs every 30k miles? Thanks in advance !

 

108,000 miles on my 07 4.0ltr. . 20k of them by me. think i still have stock plugs

 

I just changed my spark plugs in my 5vz-fe and it had 112k miles and stock plugs. They were starting to get bad. My cousin had 135k on his when his started to go bad.

 

Ask Whippersnapper about how great the E3 sparkplugs are, if you want to talk about performance.

 

These days you get a lot more out of your plugs, and the ECM helps get even more from there. 75K is a good number but you CAN wait longer.

 

All joking aside, if the manufacturer suggests 30k for best performance and it costs less than $15 and takes less than 15 minutes, why the hell wouldn't you do it?

 

15 minutes? Holy smoke you must be a knuckle dragger speed demon.

I could do my last Honda in 15, but that was just 4 bolts for the coil packs.

The 4.0L, pass side took 5 minutes, and the driver's side took an hour and a half. Word of advice, don't drop your 10mm socket into the frame crossmember when trying to bolt down that utterly retarded clutch hardline support bracket (why did they bolt the clutch line to the intake manifold anyways?!?!).

I had about 32k or so when I changed them and the NGKs were quite worn, one of them over 0.060" gap. The Densos were much better, the widest of them was 0.048" iirc. If only I'd have known BEFORE I bought a half dozen NGKs.

 

I always changed my plugs in previous vehicles every year, just so they wouldnt get stuck to the block. I dont drive as much as I used to, so I think I'll stretch it out to two years, regardless of mileage

 

Put a little anti-seize on the threads and you'll be good to go for the recommended maintenance interval

 

What!? Always use the same plugs on both sides, the reason you might think it is supposes to be that was is because the factory had the heads built a 2 seperate factories, and somebody didnt get the memo on what plugs to use....

I run denso plugs, and recommend changing them every 30-40K miles, they really dont take long to change, and not that expensive

By 75K you plug gap should have increased by roughly 25%+, doesnt that mean a bigger spark? Well kinda, but not really. You want the recommended gap for proper operation, its going to work much better..

 

Good thread, I just had the same question!

What kind of oil does Toyota use?