Down inner boost?

Hi Roy,

I've read a number of responses to this question before.

The consensus seems to be anywhere from 7-15 degrees, with most people suggesting around 10 degrees. A simple way to get an estimate is to compare the fill weight of the summerlite and the ultralite (both from WM with same 'cut'), and then check how much extra fill weight you get from these garments (about 2oz each I think). The summerlite and ultralite are rated 10 degrees different, and the fill weight difference is around 7oz I think. So I think you might be pushing it to get an extra 15 degrees from that setup, but it wouldn't surprise me if you could squeeze 10 out of it.

HTH, Ashley

Ashley,

I concur with your analysis. In a similar vein, comparing the the regular size MB SS #2 and #3 there is a 4 oz difference in 800 fill for a 10F difference in temperature ratings. I have lab tested the insulation value of the MB #2. It tested, with the EN13537 methodology, the same temp as MB's rating.

There is probably a technical measurement, but I think it's more variable and subjective than that.

For example, last week it was pretty cold during the night, pushing the lower limits of my quilt. In addition to that, there were gaps between my pad and my quilt letting cold air in when I lay on my side. I draped my down sweater over my butt and upper legs and felt nice and toasty again.

So while there may be a technical measurement, there's also the way you use it.

Hey just wanted to say thanks for the info … got to test it out this past weekend and think you guys were right on the money. Paired with the Golite ultra I was TOASTY down in the mid-twenties. You guys ROCK!

Glad it worked out. Thanks for reporting back. =-)