Just bought new coils, but....
 

Well well I want to save some money so I just bought 4 BWD/Intermotor Ignition Coil from advance auto part, with a "wow" deal. They are supposed to be the same as OEM coils.

Those coils were shipped from different stores, and I finally received them all. But apparently there are some differences between those coils

1st there are 3 coils, they are the same, the forth coil, looks more like an OEM one. from the pics, you can see the 4th one has metal parts like aluminum, appearing a silver looking. The rest all look like copper.

Also, the 4th coil is the only one with Mazda part number onto it, and the bottom is black rubber, the rest three all have brown rubber at the bottom.

That's all the differences I noticed. The 4th one looks totally like OEM parts, however it actually looks older than the other three. Other three, they are brand new, but slightly different from the OEM...

Ok do you think this does matter? Should I put them onto my '8?

Thanks a bunch in advance!

This is why I don't buy cheap parts. You never really know what you are getting.

Looks like the coils came from two different suppliers/manufacturers. Interesting. I don't know if there is a difference in quality/operation. But you might want to get a matching set.

OK, I looked at the packaging box, the three are made in poland, the one is made in Japan...hell I thought all BWD were made in Japan..

I just heard ppl keep talking about these coils are completely the same as any Mazda dealer will provide you. As for that Japanese one, guess it's true. Little concerned about the rest three

I got the exact same ignition coils from an o'reilys 2 weeks ago and changed them, I was well over due for new coils (changed at 45k), and i've put about 200+ miles on them so far, so far im satisfied, smooth idle and starts up without a problem.

plus they have a lifetime warranty according to what the guy told me at the auto parts store I can bring them in whenever I feel that they are failing on me (not that i am going to keep using these coils) only until i save up for the BHR ignition coils

I can keep updates on how they are on the long run if you like

Good to know. Do you have the coils also like mine? some look slightly different from the others?

They're probably fine to install. If you're bothered, replace the fourth one with a Polish version.

I'd just install them and keep driving.

I'll check later the under part of the coil looks exactly the same

I'd rather have everything the same, just to be safe.

Install them and keep the used one as spare..

Honestly, I'd bring them back to AAP and show them the difference.
Maybe they'll swap it out and give you the correct ones.

I've learned from the past, never to skimp on parts. There are plenty of vendors that give great deals on coil/wires/plug packages or even just coil sets itself.

cheaper solution would have been to actually test the old coils to see if they were bad.

They are just from different manufacturing sites. They should function the same.

I had the same scenario with the coils I received from Advance Auto. I installed them anyway, and the car runs fine. At 41,000 miles, the new coils made no difference in the running quality of the car, so I'm keeping the original coils for later.

Strangely, 3 of the original coils showed the usual heat marks on the bottom, but the coil in back showed no sign of this.

The "heat marks" are meaningless.

Thanks for clarifying that.

I keep reading posts in which people refer to those heat marks as the determining factor to know that coils are bad.

same here I switched my original coils out at 45k but didn't feel that much of a difference other than a quicker start up and a steady smooth idle, so i guess that would mean a big difference

I would go back to the vendor and get them to give you a matching set, they will do it no problem if they value your business. If that is not an option, install them and make sure they work correctly and just forget about it

I know this, and I never suggested that the heat marks meant anything in particular. I was only pointing out the oddness of 1 coil not having a heat mark when the other 3 did...