Review on Mishimoto Low-Temperature Racing Thermostat (MMTS-RAM-99L) - Compatible with Dodge Cummins 5.9L & 6.7L (1999-2013) by Isaac Samal

. I installed one of these thermostats when building a Mishimoto radiator on a Cummings diesel. It worked really cool for a few days and then seemed to open later and later. He adjusted the opening from 205 to 210 and kept the car temp around 205 and obviously higher when towing. I let it run for a few months. I was frustrated that he was 180 stats and picking up the pace so much before I saw him open. I added an equivalent stant and it opens earlier and runs about 5 degrees cooler at 80 mph and about 15 degrees cooler at 65 mph. I leave the Mishimoto radiator and transmission cooler, but the thermostat is the hard way.