After reading all the posts on the wonders of RedLine I decided to give it a try. Did the Redline gas treatment last week on the sons 91 FJ 80 with 169,000 mi. and got some good results. Turned the oil black, proly not to good but it increased the pickup and gas mileage went from a constant highway 12 up to 15. Mileage was done on the exact same drive to the cabin three weeks appart. Little scared about the oil. Seems like I might be getting some blow by but the oil is usually very clean between changes of 4000 mi. It has been discollored only twice, once with the engine flush and this time. I use 10-30 Castrol high mileage. Comments?