The interval that is perfectly fine for one car could be way too long for another. So in reality, very few drivers will go 25,000 miles without an oil change, even if they spring for high-grade synthetic oil. And most of them shouldn't, although some can go 10,000 without a problem [source: CIWMB ].
What happens if I go too long without an oil change?
Go long enough without an oil change, and it could eventually cost you your car. Once motor oil becomes sludge, it no longer draws heat from the engine. The engine might overheat and either blow a gasket or seize up. If the heat doesn't cause a gasket to blow, it will warp the parts in your engine.
How long can I drive with old oil?
Your engine will run smoothly even if you do not change the oil too often or if you run the vehicle over the set limit. If your engine can tolerate, it will take your vehicle anywhere between 5,000 to 6,000 miles. Depending upon the age of your car, your engine can even go up to 10,000 miles.
Can I drive with dirty oil?
The short answer is yes. Dirty oil can cause serious problems for your vehicle and lead to extremely expensive repairs that could otherwise be avoided.