Driveways, garages, car parks and city streets are all susceptible to staining and damage from oil leaks. Cars that leak engine oil should be examined and repaired and existing spots and stains should be treated.
Damage
Leaks leave stains on asphalt, which can lead to permanent discolouration. More damaging, though, is the possibility of long term exposure to oil leaks. Over time, asphalt will absorb the oil, which can soften the nature of the asphalt. This allows the oil to eat away the asphalt, causing irreversible damage.
Cleaning Spills
Warm water and dishwashing liquid helps to remove oil from asphalt. Commercial oil-absorbing solvents also are available at speciality stores, and should be used as necessary and only according to the directions on the product.
Avoiding Long-Term Damage
Sealing asphalt and maintaining the sealant over time---as recommended by the product directions or your contractor---are the best ways to avoid long-term damage. Clean spills when you notice them---by using a professional solution or water and soap---and maintain vehicles to avoid leaks and prevent unnecessary damage and expense.