Can't say enough good stuff about this oil additive. This works for older cars, but I started using this on my 2000 Jeep Grand Cherokee with 223k miles when I purchased it. I use this additive every time I change my oil. Think of this additive as an oil detergent which keeps the sludge suspended in the oil, which allows for easier filtering.What I use:Rislone Engine TreatmentValvoline Max Life High Mileage 10W-30Bosch D3402 Distance Plus High Performance Oil FilterRislone needs more Caitlin videos.