A high mileage warranty will vary depending on where you get your warranty from. Different companies have different ideas of what deems a car to have high mileage. Certain companies will consider anything over 60,000 miles to be higher, while others will have a higher minimum set, such as a 100,000, and 90,000 miles would not. Meanwhile, other companies will base term high mileage on a mile verses age basis. An average car does between 10,000 and 15,000 miles annually. Therefore, a five year old car with over 75,000 miles on the clock will be considered to have high mileage, as it has above average mileage.