Not warm enough! Sierra Designs has been around a…
Fill: Polarguard delta
Temperature Rating: 15 degrees F
Weight: 3 lb 1 oz
Price Paid: $110
Not warm enough! Sierra Designs has been around a long time so I decided to give their synthetic bags a try. (I have an old North Face goose down bag from 1973 that is rated for 0 degrees F which I actually slept in on a night that was 12 degrees F. I was comfortable enough) Fast forward to this summer up at Truckee 7000 ft. elevation and I slept in a Sierra Design Cochise regular bag rated at 15 degrees F. with an outside temperature of 35-40 degrees F. I WAS COLD!!!
Don't know how they rate bags these days. Maybe you have to sleep with a liner and long underwear and eat some food before bed time. All I know is I was cold. This bag might be better for a warmer climate but not 15 degrees as it is rated.
I just tried this bag again in my backyard with a brand new MSR Mutha Hubba 3-man tent, a new REI lite core sleeping 1.5" self inflating sleeping pad, and a Cool max sleeping bag liner that is suppose to add up to 8 degrees of warmth. I also ate some cashews and chocolate 30 minutes before bedtime. I was cold and the temperature was only 44 degrees in the tent at 2:30 a.m. before I put on a wool hat, wool socks, Patagonia lightweight silk long underwear tops and bottoms. At 5:30 a.m. it was 42 degrees in the tent, I was still a little cold and decided to go back into the house.
This bag is designed well enough just not enough fill and loft to rate it as 15 degrees. I measured the loft to be only 4 inches and I have been storing the bag in my closet unstuffed. After reading the customer reviews of the bags that have the Polarguard Delta I have serious reservations about their longevity.