135, and no probs here, but I really don't consider 135 'high' mileage.

 

144K on stock plugs. Over 2K on replacements on 01 Crew 5.4.

 

No blowout's here changed em at 82,000 and have 107,000 now

 

115k on my 06 plugs change at 65k doin it again at 125k
not to many issues to speak of yet

 

Ok guys, well I have as of today over 145,000 miles and last nite I had one plug blow out of #3 and broke the coil and the plug hit the hood but no damage to it, thank ford for all the pading under the hood.

 

Thinking about it and looking back, you're right-

 

210,000 + miles and no issues with the plugs... I changed out the stock plugs just after I bought the truck in 2001 with around 63,000 miles on it. I'm still on those same replacement plugs now and it's still giving me 15+ mpg average with no miss or shudder or any of the other issues that non MC plugs are supposed to deliver...

I'm regularly towing the TT in my sig and it's not skipped a beat.. The only stuff I've had to do to the engine is an alternator, 1 bad COP and a IAC. These all happened over 5 years ago too. Most recently was a new starter and a battery. Other then that, it's been regular maintenance stuff..

Mitch

 

155xxx with no issues and shes been boosted for 70xxx of it. I have changed the plugs 4 or 5 times thoe.