Now let me start by saying i was really worried about doing this and destroying my cooling system and possible top end but........ I followed all the directions on the bottle and i have not lost a drop of coolant. The missfire codes that kept popping up stopped. Now on the bottle it says to run the mixture thru without the thermostat in but on the Reno obviously that is not an option. I ran the stuff for a half hour and then drained it. At that point I took the stat off to prevent it from being locked up. I have ran my car for about 1000 miles since i have done this and no problems at all. I used the K&W perm headgasket sealer with NANOTECHNOLOGY. This is definantly the poor mans fix.