I was a Purolator guy too until the change. I have been using the Mobil 1 m1-108 because they are easy to find locally. I looked around on the interwebs and seems that Mobil 1 updated their entire extended performance filter line and all of the new filters have the "a" at the end. On their website it does say that the 108a replaces the 108. I have a 108 on now and I'll see if it is the same as the new 108a and report back. For what it's worth the 108a isn't convex, it's more flat but I can't remember what if the 108 was flat as well.
2006 865 Neon Blue/Jet Black Speedmaster,790cams, TTP Stage 2 Firestarter, Epco Exhaust with 10.25" Samson Vrod baffles, UNI pods with 40 pilots, 150 mains,Thruxton needles, 3 turns out.
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