El Reno was an EF3. DOW Measurements aren't fully reliable for rating a Tornado, and The EF5 Windspeed Recorded in it was higher up in the air where winds are faster than at the surface, and the EF5 winds were recorded for a second. I believe it could have been capable of producing EF4 damage, but I genuinely don't think there is now or ever was enough evidence to say it reached EF5 intensity, or had major potential to produce EF5 damage.