[fordracing65]

I have seen this also, I believe a dynojet uses large steel roller to contain mass, the mass is fixed and can never change, so they are the same fromdyno to dyno day to day, where as a mustang dyno is an electric load dyno, so its not a true inertia dyno, taking into many consideration which may lead to less hp numbers on average, but im really just guessing here, I always see mustang dyno's around me..