you really wanna roll the dice to save $50 bucks?

this is why used Evo's are so scary

 

20k is actually pretty good on a modified turbo car.

 

So far about 18,000 miles on these plugs, regapped them to .022 before installing, and zero issues... Less detonation - ping and no fouling issues yet.

Worth a look into....Would like to see a comparison vrs NGK stockers on a dyno. The Autolites do seem to be at least 1 step colder than stock.

Chris

 

25,000 miles and zero issues. Gapped them at .022, they come outta the box gapped around .045, since they also fit some NA applications.

2009 Ralliart, 93 tune 25 psi max boost, full bolt ons.

 

Red color is from a fuel additive that contained MMT, from my testing I will say these are about 1.5 heat ranges colder than stock Evo X heat range. The autlite master interchange book and tech department list these plugs as 2 heat ranges colder than stock.

 

Better shot of the insulators.

 

Looks like oil in your cylinders??

It seems a set of spark plugs are only good for 2-3 trackdays before they become fouled up. I've soaked mine in seafoam and that seems to extend their life another trackday or two. I don't know why but they get all fouled up and i can tell at idle and low throttle putting around its not very smooth.

I'm considering these autolites as i'm positive they'd foul up in the same time frame but are much cheaper to replace.....

 

86,000 miles on her, time for a ton of work... Timing chain, cams, n more!!