unbelievable.....

[CutthroatSlam]

I DIY just about everything, even though I can afford to pay someone. When I look at the ridiculous costs for maintenance and repairs, I have to gross that up for taxes as I’d pay for them with after tax income.

Something as easy as spark plug replacement is a no brainer. Set of spark plugs is like $45 and it takes an hour of my time.

 

[seatia]

They will last well into the 150K+ range, normally see them burning out around 190,000-200,000 but have seen / heard of instances where people didnt replace them until one burnt out around 250,000

drivers side, normally the middle or rear cylinder is always the one that shows the most wear on the electrode. Cant confirm why, but they will typically go well over 100K miles.

I changed Denso Iridium's in a F150 at over 250k miles.
Great plugs.

 

[DAW89446]

So what's the average lifespan of the original plugs anyway?

Maybe not apples to apples, but FWIW. I didn’t change the plugs on my ‘02 Tacoma TRD 3.4 V6 5-speed until after 175,000 miles. The truck was running OK, just a bit of hesitation mashing the throttle at lower RPMs in a higher gear. I’m not mechanically inclined, don’t have a garage, not blessed with a plethora of tools, was a bit nervous about the deep holes for the plugs and coil on plug set up. A one man shop charged me $200 for NGK plugs and installation.