Depending on your vehicle use, your ‘Oil change required’ light may come on your instrument cluster. This can range from 3,000 miles (most severe use: max load/towing, extreme hot/cold) up to 10,000 miles (normal use: normal commuting, highway driving, little to no loading, flat terrain, no extended idling). On the Ford Focus MK3 (years 2011-2018), if you have changed your own oil (or the the shop forgot to reset your oil change reset indicator, you can easily do it by yourself.