Product InformationThe Mishimoto Chevrolet Duramax low temperature thermostats activate at a lower temperature than the OEM thermostats, making them the perfect solution for Duramax owners who live in warmer climates, or use their trucks under heavy load or strenuous driving conditions.Activating at a lower temperature means coolant will begin flowing through the system and allow for cooler temperatures. Mishimoto Chevrolet/GMC 6.6L Duramax Engine Low Temperature Thermostats (set of 2) MMTS-CHV-01DL 2006-2009 Chevrolet Express 2500 6.6 Liter 4L60-E, 2006-2009 Chevrolet Express 2500 6.6 Liter 4L80-E, 2006-2009 Chevrolet Express 2500 6.6 Liter 4L85-E, 2010-2012 Chevrolet Express 2500 6.6 Liter 6L90, 2007-2009 Chevrolet Express 3500 6.6 Liter 4L60-E, 2006-2009 Chevrolet Express 3500 6.6 Liter 4L80-E, 2006-2009 Chevrolet Express 3500 6.6 Liter 4L85-E, 2010-2012 Chevrolet Express 3500 6.6 Liter 6L90, 2009 Chevrolet Express 4500 6.6 Liter 4L60-E, 2009 Chevrolet Express 4500 6.6 Liter 4L80-E, 2009 Chevrolet Express 4500 6.6 Liter 4L85-E, 2010-2012 Chevrolet Express 4500 6.6 Liter 6L90, 2004-2012 Chevrolet Silverado 2500 HD 6.6 Liter 1000, 2001-2003 Chevrolet Silverado 2500 HD 6.6 Liter 1000/M74, 2001-2007 Chevrolet Silverado 2500 HD 6.6 Liter 4L80-E, 2002 Chevrolet Silverado 2500 HD 6.6 Liter 4L80-E-HD/MN8, 2007-2012 Chevrolet Silverado 2500 HD 6.6 Liter 6L90, 2004-2007 Chevrolet Silverado 2500 HD 6.6 Liter NV4500, 2001-2003 Chevrolet Silverado 2500 HD 6.6 Liter NV4500/MW3, 2004-2006 Chevrolet Silverado 2500 HD 6.6 Liter S6-650, 2001-2003 Chevrolet Silverado 2500 HD 6.6 Liter S6-650/ML6, 2004-2007 Chevrolet Silverado 3500 6.6 Liter 1000, 2001-2003 Chevrolet Silverado 3500 6.6 Liter 1000/M74, 2001-2007 Chevrolet Silverado 3500 6.6 Liter 4L80-E, 2004-2007 Chevrolet Silverado 3500 6.6 Liter NV4500, 2001-2003 Chevrolet Silverado 3500 6.6 Liter NV4500/MW3, 2004-2006 Chevrolet Silverado 3500 6.6 Liter S6-650, 2001-2003 Chevrolet Silverado 3500 6.6 Liter S6-650/ML6, 2007-2012 Chevrolet Silverado 3500 HD 6.6 Liter 1000, 2007-2012 Chevrolet Silverado 3500 HD 6.6 Liter 6L90, 2006-2009 GMC Savana 2500 6.6 Liter 4L60-E, 2006-2009 GMC Savana 2500 6.6 Liter 4L80-E, 2006-2009 GMC Savana 2500 6.6 Liter 4L85-E, 2010-2012 GMC Savana 2500 6.6 Liter 6L90, 2006-2009 GMC Savana 3500 6.6 Liter 4L60-E, 2006-2009 GMC Savana 3500 6.6 Liter 4L80-E, 2006-2009 GMC Savana 3500 6.6 Liter 4L85-E, 2010-2012 GMC Savana 3500 6.6 Liter 6L90 …See Application Guide for Additional FitmentsFits: Chevrolet Express 2500 Base 2006 to 2016 Chevrolet Express 2500 LS 2006 to 2016 Chevrolet Express 2500 LT 2006 to 2016 Chevrolet Express 3500 Base 2006 to 2016 Chevrolet Express 3500 LS 2006 to 2016 Chevrolet Express 3500 LT 2006 to 2016 Chevrolet Silverado 2500 HD Base 2001 to 2005 Chevrolet Silverado 2500 HD Custom 2020 to 2021 Chevrolet Silverado 2500 HD High Country 2015 to 2021 Chevrolet Silverado 2500 HD LS 2001 to 2006 Chevrolet Silverado 2500 HD LT 2001 to 2021 Chevrolet Silverado 2500 HD LTZ 2007 to 2021 Chevrolet Silverado 2500 HD WT 2003 to 2021 Chevrolet Silverado 2500 HD Classic LS 2007 Chevrolet Silverado 2500 HD Classic LT 2007 Chevrolet Silverado 2500 HD Classic WT 2007 Chevrolet Silverado 3500 Base 2001 to 2005 Chevrolet Silverado 3500 LS 2001 to 2006 Chevrolet Silverado 3500 LT 2001 to 2006 Chevrolet Silverado 3500 WT 2004 Chevrolet Silverado 3500 WT 2006 Chevrolet Silverado 3500 Classic LS 2007 Chevrolet Silverado 3500 Classic LT 2007 Chevrolet Silverado 3500 Classic WT 2007 Chevrolet Silverado 3500 HD High Country 2015 to 2021 Chevrolet Silverado 3500 HD LT 2007 to 2021 Chevrolet Silverado 3500 HD LTZ 2007 to 2021 Chevrolet Silverado 3500 HD WT 2007 to 2021 GMC Savana 2500 Base 2006 to 2016 GMC Savana 2500 LS 2007 to 2016 GMC Savana 2500 LT 2007 to 2016 GMC Savana 3500 Base 2006 to 2016 GMC Savana 3500 LS 2006 to 2016 GMC Savana 3500 LT 2006 to 2016 GMC Sierra 2500 HD Base 2002 to 2005 GMC Sierra 2500 HD Base 2015 to 2021 GMC Sierra 2500 HD Denali 2011 to 2021 GMC Sierra 2500 HD SL 2001 to 2002 GMC Sierra 2500 HD SL 2006 GMC Sierra 2500 HD SLE 2001 to 2021 GMC Sierra 2500 HD SLT 2001 to 2021 GMC Sierra 2500 HD WT 2003 to 2014 GMC Sierra 2500 HD Classic SL 2007 GMC Sierra 2500 HD Classic SLE 2007 GMC Sierra 2500 HD Classic SLT 2007 GMC Sierra 2500 HD Classic WT 2007 GMC Sierra 3500 Base 2002 to 2005 GMC Sierra 3500 SL 2001 to 2002 GMC Sierra 3500 SL 2006 GMC Sierra 3500 SLE 2001 to 2006 GMC Sierra 3500 SLT 2001 to 2006 GMC Sierra 3500 WT 2004 to 2006 GMC Sierra 3500 Classic SL 2007 GMC Sierra 3500 Classic SLE 2007 GMC Sierra 3500 Classic SLT 2007 GMC Sierra 3500 Classic WT 2007 GMC Sierra 3500 HD Base 2015 to 2021 GMC Sierra 3500 HD Denali 2011 to 2021 GMC Sierra 3500 HD SLE 2007 to 2021 GMC Sierra 3500 HD SLT 2007 to 2021 GMC Sierra 3500 HD WT 2007 to 2014