Coleman 0 degree sleeping bag.

[Wokman]

I'm in it now, and colder than I expected. It's only about 20. My buddy picked up a department store one that's a 10 degree. Are we doing something wrong?

[Slo-go'en]

Bag ratings are often that which will keep you alive, not comfortable and a Coleman or department store bag will often be pretty optimistic on that rating too.

Plus there a lot of other variables to also consider. How good is the insulation under you? How well is it cinched up to prevent drafts? Is there a lot of extra space inside? What kind of clothes are you wearing? Do you have a hat on? Have you had enough to eat? Do you have to pee?

[Wokman]

I know I could be warmer with a sleeping pad and the rest of the bag zipped up but I was more complaining than anything. Oatmeal for dinner and I'm only wearing two pairs of socks

[Second Hand]

If you don't have a sleeping pad and your not fully zipped up, your probably doing okay.

For what it's worth, my first "cold weather" sleeping bag was a coleman. I used it for several winter car camping trips. I now have a 20 degree Serra Design's bag that I've been able to take down much colder than my "0 degree" Coleman.

I have really retired the coleman at this point

[Wokman]

I've been planning to do the whole trail for quite a while now. I have been trying to put things into practical application before going out on go long haul. Im just 26 married with 2 kids so it keeps getting put off every year. But I'm only truly here for the family.

[bemental]

What's your bag made of? Mind describing the design characteristics of it for us?

[Wokman]

Its a mummy bag. I'm in the dark and could probably tell you better when I get home tomorrow

[bigcranky]

A pad is crucial in cold weather -- the ground will suck all the heat out of your body without one. Even just a $20 Walmart blue foam pad will be warm enough at 20-F. The bag doesn't provide any insulation from the ground, as your body weight crushes any down or synthetic insulation below you.

[bigcranky]

For the time being, anything you can put between you and the ground will help. Leaves, your empty pack, extra clothing, etc.

[Sarcasm the elf]

A pad is crucial in cold weather -- the ground will suck all the heat out of your body without one. Even just a $20 Walmart blue foam pad will be warm enough at 20-F. The bag doesn't provide any insulation from the ground, as your body weight crushes any down or synthetic insulation below you.

This. Generally a temperature rating assumes that you are sleeping on an appropriate pad (for zero degree weather two foam pads on top of each-other is appropriate), inside a tent, and have the bag fully snugged down. Plus as others have said, temperature ratings are highly subjective and dept store brands are usually overly optimistic.

Funny story, last year I was camping in single digit weather using my very nice zero degree down bag, but unfortunately also using my old crappy thin foam pad that didn't provide anywhere near enough insulation. The whole night I kept tossing and turning, whatever side of my body was laying against the pad and the ground was absolutely freezing and whatever side was on top was sweating from the down bag. It was so uncomfortable that I had to roll over every few minutes for the whole night.

[rocketsocks]

This. Generally a temperature rating assumes that you are sleeping on an appropriate pad (for zero degree weather two foam pads on top of each-other is appropriate), inside a tent, and have the bag fully snugged down. Plus as others have said, temperature ratings are highly subjective and dept store brands are usually overly optimistic.

Funny story, last year I was camping in single digit weather using my very nice zero degree down bag, but unfortunately also using my old crappy thin foam pad that didn't provide anywhere near enough insulation. The whole night I kept tossing and turning, whatever side of my body was laying against the pad and the ground was absolutely freezing and whatever side was on top was sweating from the down bag. It was so uncomfortable that I had to roll over every few minutes for the whole night.

I know the night your talkin' about...I had a air mattress and a CC foam pad, with a 15 degree bag, I was cold all night as well.

...lesson learned. I need More bag, and more pad to sleep in the winter snows.

[fiddlehead]

If you are worried that your bag is not sufficient to keep you warm, you should probably learn the hot water bottle trick to sleep with at night.

[4eyedbuzzard]

A couple of points:
1) There are manufacturer ratings, and then there are the "standardized" EN ratings which tend to be more conservative. I don't know which Coleman is using, but I'm guessing it's probably not the EN ratings. And even with EN ratings, I wouldn't try to push the limits beyond the "comfort" rating. The extreme ratings might keep you alive, but you'd be miserably cold.
2) I've always found that it's good to have a bag that is EN comfort rated at least as warm as the actual temperatures experienced. First, bag ratings even from great companies like WM, FF, and others are rated under ideal conditions. Insulated pad suitable for temperature encountered. No wind (tent or bivy or some wind proof shelter). Dry bag. No delofting due to prolonged use, moisture build up, etc. The EN comfort ratings already factor in the wearing of a base layer, socks, and hat. So a base layer is not an additional source of insulation. Add in that when you are tired and cold, your body will divert blood flow (and hence heat) to your core, making you and your extremities feel even colder.
3) If there is one gear item that you shouldn't cut corners on it's your sleeping bag. Almost every hiker will agree with my sentiments on this. The best single gear purchases I have ever made are two high quality sleeping bags. I say the best, not because of price as they weren't cheap, but because they have kept me warm and happy and haven't been made obsolete from a practical or weight standpoint by technology. The one I use most is a Western Mountaineering 35° bag purchased about 8 years ago, the other an older North Face 15° bag that is going on 25 years old. Kept reasonably clean and stored uncompressed they will likely outlive my use. These are just examples. There are other quality manufacturers. But do your research and also try on the bag or a similarly sized before buying one. They don't all fit the same, which if you are wide in the shoulders can be an issue.