Spark plug OEM FORD or Autolite

I went 134,000 miles on a set of spark plugs on my 11 Ford Fiesta which is, what, a bit around 215,000 km? They were still in decent shape when I pulled them, just a bit out of gap spec, and I was still getting really good fuel mileage.

In my 206 classes we run this autolite sparkplug because it’s required.

My understanding is that we switched because people were buying plugs in bulk and looking for ones with the lowest internal resistance believing it would effectively advance the engines timing. Supposedly these autolite plugs are much more consistent.

If you care more about performance, or cheaper cost, get the autolite a103, or ar103. Those will give you the best performance, but they only last like 10k. But they’re also dirt cheap.

Had to replace the plugs and ignition coils last summer and that fixed it.

after changing the spark plug for another autolite it stopped misfiring its still a little rough so I fear it may comeback so I just ordered some NGK plugs.

Also, Autolite is extra terrible. I would have done anything else.

Local mechanic used an Autolite plug, not Honda-recommended NGK. Misfires stopped for a month, then happened twice more. I have since discovered this brand does not run well in a Honda engine.

I changed my plugs to autolite because I had never heard anything bad about them. I replaced them after 3 weeks due to misfires, put another set of autolites in and it ran fine for 2 weeks. Started misfiring again and swapped in a set of NGK's, no problems since.

I would never install Autolite on any car, definitely not the WRX.

Out of all my years replacing spark plugs. The only times I got bad spark plugs that misfired right away is the one time I ordered a fake set thru ebay(my fault for not doing my due diligence) and a set of brand new auto lites from autozone.