Spark plug Autolite or Denso

And, before you get too far, are you replacing with the right plugs? I presume it’s the 2AZ 4-cyl since you’re not asking us how to get to the back plugs. The right ones are the Denso Iridium Long Life or the NGK Laser Iridium.

I have autolite xp in the van. $100 for 6 ngk, $90 for denso with a van with 250k miles. Everyone says there crap, but it runs great.

I use Denso IK20TT and these spark plugs work every time, on both fuels.

I put Autolite Iridium plugs in my '06 N52 20k miles ago because of a crazy sale/rebate. It runs as smooth as a new one.

I put denso 5310 in mine, apparently they are supposed to give you a slight increase in power if you use premium fuel.

Idk if I gained any power, but the car runs well.

You're on the right track- replace those worn out plugs. Pre-detonation started on my '18 at 30k. Increasing octane rating to 93 worked up to 58k miles. $50 for a new set of [Autolite Iridium XP5363](https://www.amazon.com/dp/B078KWTCF2?ref=ppx_pop_mob_ap_share) resolved this problem.

I just installed a set of Iridium XP 6203 in my Optima 2015 and they're working fine. Gap was incorrect on 2 of them, but was easy to fix.

Don't even think the Autolite or Bosch last as long as Denso/NGK spark plugs.

autolites were fine 100 years ago

now stick with NGK or whatever OEM was. its not worth it to be fudging around and what little your gonna save may be burned up in less MPG using some other plug.

I've had nothing but bad luck with Autolite brand.