Fleece Performance 07.5-24 Dodge RAM 6.7L Cummins Cold Weather Upgrade Kit6. 7L Cummins owners: Our add on cold weather kit for the Fleece Performance intake and grid heater kit provides proven engine startability down to 35 centigrade! Optimized heater design and placement in the intake air stream ensure you get the most efficient heating possible. Compared with other grid heating kits on the market, the Fleece Performance kit achieves the same levels of cold temperature startability with lower wattage and less strain on