Great question. Unfortunately the answer is no. Shimano changed the spline depth on the Mx100 series and therefore, an XT M8100 power meter won’t fit on a Shimano XT M8000 crankset. Here are your two best power meter options for an M8000 crankset:
Power Meter Pedals
MTB power meter pedals can be installed on any MTB crankset. We have both the Garmin Rally XC and the SRM X-Power. These pedals use standard SPD cleats and come in both single- and dual-sided versions.
Pros: Easy to install, works on any bike, can move from bike to bike, don’t have to change crankset
Crankset Power Meter
You can also change out your XT M8000 crankset for a new power-equipped version. This would be a bit more work and would likely be more expensive, but it’s another option none-the-less. We have several MTB power meter cranksets to choose from.
Pros: Accurate, reliable, measures both legs
Cons: More expensive, more work to install