Most guitar players want to make sure that anything they do with their instrument will keep it in top condition. The good news here is that using drop tuning won't have any detrimental effects to your instrument. In fact, some people who own older and vintage guitars actually prefer it because it places less stress and tension on the neck of the guitar. However, if you keep your guitar in drop tuning for most of the time then you will more than likely need to make a slight adjustment to your intonation at some point.