AFR misleading? Plugs tell a better story?

Innovate's gauges are calibrated to show 14.7 when the engine's running at stoich, so even if you use E10 or E85, it'll show 14.7 at stoich. I called their tech line to verify this when I got mine. Either way, some engines just don't like running that lean; I've found that cruise in the 14-15 range and power in the 12-13 range will keep most engines running pretty well.