My experience is that the EC2/Coils/Spark Plugs (mentioned) are all compatible ... based on using both stock Mazda Plugs and the BR10EIX.
I say the BR10EIX last longer than stock Mazda plugs and whenever the engine won't start or runs rough - it has been the plugs - don't bother trying to clean them - replace them with NEW ones.
Jeff

According to NGK, the Br10EIX is a resistor plug.
According to Autolite, it crosses to their AR2592 (or their 4051), but Autolite specs both those plugs as non-resistor plugs.

Should we assume that the GM coils Tracy specs don't care whether the plugs are resistor or not?
Or are we expected to swap between resistor & non-resistor wire when we swap plugs?

Charlie

-----Original Message-----
From: Jeff Whaley
Sent: February-03-22 8:18 AM
To: 'Rotary motors in aircraft' <flyrotary@lancaironline.net>
Subject: Re: [FlyRotary] Autolite AR2592 vs NGK BR10EIX

Yes, your data points are correct ... and the AR2592 were definitely suggested by LEHanover ... the BR10EIX suggestion may have come from Steve Boese.
I am using the BR10EIX as well - have never tried the AR2592.
Jeff

Hi Finn

That's what I understood - I think this info may have come from Lyn Hanover. "Cheaper racers use Autolite AR2592"
I recently purchased 4 as they were cheap but I haven't tried them yet.

Steve Izett

> On 3 Feb 2022, at 4:25 am, Finn Lassen finn.lassen@verizon.net <flyrotary@lancaironline.net> wrote:
>
> Any experience on Autolite vs NGK?
>
> Can get a 8-pack of Autolite AR2592 for $28.
>
> 4-pack of NGK Iridium IX Spark Plugs BR10EIX SOLID/6957 for $36.
>
> Is more than double the price for the NGK worth it?
>
> Am I correct my understanding that both of the above are the colder plugs recommended in place of the stock Renesis plugs?
>
> Finn