Gear-obsessed editors choose every product we review. We may earn commission if you buy from a link. Why Trust Us? Changing the car differential oil—it's one of the most-overlooked maintenance tasks ...

Let's be honest, the average person has never thought about whether differentials even have fluid. They're not like engines, which require oil changes after about 5,000 to 10,000 miles (or 12,500 if ...