Only you can answer that question! Do the vehicles run better after the Seafoam treatment? Idle smoother? Accelerate better?

I noticed a difference in my 97 Nissan hardbody truck and 95 Contour after using the Seafoam. The Contour would stumble a little bit before reaching 3000 rpms while accelerating. After the Seafoam, it has crisper throttle response from idle through redline. Great stuff!

1995 Contour SE, Duratec V6, 5 Speed