Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Bought it but didn't use it.

I brought this product to my mechanic to see if it is advisable to add to my coolant while at service. He told me never use with aluminum radiators. Also there is nothing wrong with my coolant system so he flushed the system with distill water and added Toyota Red coolant to a mix approximately 50/50.The mechanic added, only Royal Purple product he might use is brake fluid for its color so when you flush the brake system you can easier to tell the fluid is clear when purple fluid starts breeds out.I was laughing reading those reviews of swearing up and down how good all the Royal Purple products are. Those clowns are very likely working for or owning Royal Purple.