Review: Sierra Designs Nitro 800 mummy || Great price, ordinary design

Cowboy camping in Tablelands at 11,000 feet in September, using the new 20-degree Nitro 800 mummy bag from Sierra Designs

The Sierra Designs spring 2018 line-up has two themes: (1) back to basics, and (2) better pricing. Innovation is not entirely lacking, evidenced by the “zipperless mummy” Cloud series (my review) and the High Side Tent (my review), but the “better and different” mantra was no longer a requirement of new products.

Review: Sierra Designs Nitro 800 mummy bag

These two themes are both embodied in the new Nitro 800 bags: the designs are solid and well executed, but relatively ordinary; and the prices are very competitive.

I slept in the Nitro 800 20-degree for two consecutive weeks last month while guiding trips in Sequoia-Kings Canyon National Park. Nighttime low temperatures were normally in the high-20’s, except for a few nights after a cold front moved through — a nearby monitoring station recorded 13 degrees, although our deliberately selected campsite was probably five degrees warmer. Some nights I slept inside a full-sided tent, but most others I slept my favorite way: cowboy camping under the stars.

In sub-freezing conditions, I abandon my summer quilt in favor of a mummy bag — quilts are too drafty and they leave my head too exposed. Yes, I could carry an insulated balaclava, but a hooded mummy bag is simpler, lighter, more thermally efficient, and less expensive all things being equal.

Based on these two weeks of use, I found the Nitro 800 to be:

  • Lightweight and compressible, for its warmth;
  • Comfortably sized, with room for me (6′ and 160 lbs) while wearing hiking clothes, mid-layer fleece top, puffy jacket, puffy pants, and booties;
  • Thoughtfully designed, e.g. functional hood adjustment, sufficiently long side-zipper, effective anti-snag zipper guard, and simple draft collar.

I will not offer a personal testament as to the Nitro’s temperature rating. The bags were EN tested, and these results are much more reliable when comparing the relative warmth of sleeping bags.

In terms of performance, the Nitro bags are unexceptional: the mummy market is crowded with high-quality bags, and most brands use the exact same materials, construction techniques, and Asian factories. Some brands differentiate their products with premium materials and Made in USA manufacturing (e.g. Western Mountaineering), but for the others it’s a war of weight, warmth, and price point. In this regard, the Nitro 800 generally outperforms the competition.

Another cowboy camp in sub-alpine at around 10,000 feet

Line review & specs

There are five Nitro models:

The men’s/unisex models are available in sizes Regular (up to 6′) and Long (up to 6’6″; +2-4 oz vs Regular lengths).

The temperature ratings on the women’s bags are conservative. These models are shorter and narrower (i.e. less surface area), yet contain the same amount of 800-fill down insulation as the men’s bags. As a cost-savings measure, the women’s bags were not EN-tested separately, so the published EN ratings are the same as the men’s models.

The Nitro 800 bags have a 40-inch side zipper. It was sufficient for comfortably getting into and out of the bag, while saving weight over a full-length option (at the expense of versatility).

Materials and construction are consistent across the line:

  • 800 fill-power PFC-free water-resistant DriDown
  • 15-denier shell and liner fabrics
  • 5-inch baffles, which reduces down shifting better than standard 6-inch
  • 40-inch zipper with anti-snag track
  • Cord tension system on the hood
  • Shingled foot vent for lower extremity venting
  • Contoured draft collar on 20- and 0-deg models

To learn more about the Nitro 800 series, watch this video with the Product Manager, Casey Sumnicht.

The 5-inch-wide draft dodger collar runs seam-to-seam and stays in place using the tension of the bag, not a cord tensioner. It’s a feature on the 0- and 20-degree models, not the 35 deg.

Product comps

How does the Nitro 800 compare to existing products? In the chart below I’ve tallied specs of popular mummy bags that are similar to the 35-degree model. Overall, the Nitro 800 35-degree hits a good combination of weight, warmth, and price. There are lighter 35-degree bags and there are less expensive 35-degree bags, but as far as I know there are currently no 35-degree bags that are both lighter and less expensive than the Nitro 800.

Questions or comments about the Nitro 800 series? Post it below.

Disclosure. I strive to offer field-tested and trustworthy information, insights, and advice. I have no financial affiliations with or interests in any brands or products, and I do not publish sponsored content

This website is supported by affiliate marketing, whereby for referral traffic I receive a small commission from select vendors like Amazon or REI, at no cost to the reader. As an Amazon Associate I earn from qualifying purchases.

Also, I am a product and marketing consultant for Sierra Designs. But I had zero involvement in the development of this bag.

Posted in , on October 18, 2017


  1. John on October 18, 2017 at 11:06 am

    Slightly confusing that you used 20 degree bag, but comparisons are for the lighter 30 degree bag.

    • Andrew Skurka on October 18, 2017 at 11:20 am

      It’s time-consuming to pull those spec charts together, so I stopped after one. And I started with the 35 deg model.

      If a comp chart for the 20-deg model were compiled, you wouldn’t see much movement. The changes in price and weight will be incremental for different versions of the same bag design. For example, the 20-deg Nitro (EN ratings of 28/17) is $330 and 1 lb 12 oz. The Igneo 17 Long (same EN ratings) is still slightly less expensive and slightly heavier, $300 and 2 lb 2 oz. And the Marmot Helium (the warmer version of the featured Hydrogen, with EN temps of 25 and 14) remains heavier and more expensive than the Nitro: $400 and 2 lb 1 oz.

  2. Dave N on October 18, 2017 at 3:17 pm

    Thanks for posting this review. I’ve been toying with the idea of a new 20F bag and thinking about going with a down bag this time. I will definitely give this bag a closer look. Trying to decipher the rest of your sleep system from the photos: Neo-air X-lite, Boston Marathon emergency blanket as a ground cloth, backpack and something thin, flat and white under the head/torso area?

    • Matthew on October 18, 2017 at 5:48 pm

      I’m going with compactor bag under the head/torso. I’d be curious to know why you do that, Andrew. I always leave the compactor bag in my pack.

      • Andrew Skurka on October 18, 2017 at 6:49 pm

        By putting the trash compactor bag under my upper body, it adds another layer of puncture resistance for the air pad. Upper body: mylar sheet + compactor bag. Lower body: mylar + backpack. Easy to do, and given the consequences of a leaking pad I think it’s worth it.

        • Matthew on October 18, 2017 at 7:54 pm

          That makes sense. Thanks for sharing your thinking.

    • Andrew Skurka on October 18, 2017 at 6:46 pm

      Premium down bags are almost family heirlooms. Not quite on the same level as cast iron skillets and wood planers, but close.

      Rest of sleep system:
      * Mylar blanket from Boston, mostly to keep gear out of dirt, some warmth
      * Backpack under the feet, for insulation and to reduce pressure on my back, and a 2.5-mm trash compactor bag under my upper body, as another layer of puncture resistance
      * NeoAir
      * Sleeping bag

  3. Rob on October 19, 2017 at 8:12 am

    Andrew, at the beginning of the videos, it shows Sierra Designs branded trekking poles. New product?

    What’s your opinion on Western Mountaineering bags?

    • Andrew Skurka on October 19, 2017 at 9:10 am

      Yes, new product, but I don’t know the status, e.g. release date, specs.

      Western Mountaineering is the gold standard for down sleeping bags and down apparel. If you can afford it, you can not go wrong with WM. They have been doing it a long time and understand bag/apparel design better than anyone. If I were looking for a premium+ bag I would go with WM before another brand that is competitive with them or perhaps even better than them on a spec basis.

      Feathered Friends falls into the same category as WM. For whatever reason they don’t pop up as often, though.

      • Rob on October 20, 2017 at 8:47 am

        Thanks Andrew. I’ve got a question about sleeping in mummy bags. Are you supposed to roll inside your bag, or is the bag supposed to roll with you? I’m a thrasher at night, seemingly constantly moving. I currently have a first generation Backcountry Bed, which I like, but would to drop a little more weight and eliminate some of the draftiness. So I’m looking at mummy bags, but don’t want to end up in a twisted knot by morning.

  4. Tree on November 1, 2017 at 7:51 am

    I just spent 3 nights in the Pecos Wilderness in the Nitro 20. 2 nights were above 11,500′ with temps down to 15°F. I slept under a Black Diamond Megamid.

    The last night was cowboy camping on a Mesa at about 10k elevation. Low 25°.

    I am a cold sleeper and I was never cold in the Nitro. I am quite impressed with this simple, functional bag.

  5. Kyle on December 24, 2017 at 1:45 pm

    I wish the offerings this year included a new Zissou with these fabrics, down fill, and subsequently lighter total weight. I would kill For what would essentially be a 20 degree Nitro with the Zissou dual zipper/quilt enclosure system! I wish Sierra Designs wasn’t giving up on that style so soon.

    • Kyle on January 3, 2018 at 6:10 pm

      Never mind. I see now that new, updated Zissous are coming out this spring. It wasn’t that the whole line was discontinued, just the old models being cleared out for new ones. Nothing to see here- just me being an idiot.

  6. Dan on January 11, 2018 at 6:27 pm

    Hi Andrew,

    I am wondering about the foot vent. I am mostly worried that whilst thrashing around in the night, I might accidentally vent the bag, which would be undesirable if pushing the limits on the 0-degree version. How easy would it be to accidentally kick your feet out?


    • Andrew Skurka on January 11, 2018 at 6:44 pm

      I used this bag for 2+ weeks and never “found” the foot vent, intentionally or unintentionally. (I prefer to vent from the chest.) It’s pretty well shingled/sealed, so you’re not going to flap it open unless you try.

      • Dan on January 11, 2018 at 7:50 pm

        Awesome! I’ll probably end up getting one for winter use once I decide on a length. I’m right up against the 6ft length and am torn on regular or large.

        • Andrew Skurka on January 12, 2018 at 8:24 am

          How tall are you and what is your body type (narrow, barrel)? I’m 6′ exactly and lean, and thought the Regular size was fine for the temperatures I saw, which sometimes required that I wear all my clothing layers at night, giving me unnatural girth.

          Some people advocate a larger sleeping bag for winter conditions so that you can bring clothing, wet boots, and water bottles inside. I’ve never found to need that extra volume. Water bottles don’t take up much space. Wet boots can stay outside, but make sure to open them up before you retire, otherwise you won’t be able to get your foot into them in the morning. As far as clothing, well, I think it’s better worn than laying beside you, and it tends to take up less space that way too.

  7. Dan on May 30, 2018 at 3:34 am

    Hi Andrew!

    First of, thanks for the review.
    I kind of have the same dilema as the other Dan here, but I’m 6 feet and 1.23 inches tall, and I’m over the regular limit, but I know that usually sleeping bags have an extra inch or two of length inside. This is why I’m really tempted to go for the regular version, and save on the extra weight, bulkiness, and money. Would definitely try one before ordering, but there’s no place where I could do that in my area.
    S, do you happen to know the exact length on the inside? I’ve contacted Sierra Designs, but still haven’t received any answer,


    • Andrew Skurka on May 30, 2018 at 7:25 am

      I don’t know the inside seam length, sorry. I’m not surprised that CS is struggling to find it — unless they had asked for it previously, the number is going to be buried in developer files.

    • Rob on May 30, 2018 at 8:20 am

      Dan, I just got back from a three day trip to Yosemite with this bag, and I really like it so far. Had a morning where the brief rain we got during the night was ice on our tents, and I was plenty warm. But, I just measured, with the bag inside out, straight-line from the foot seam to the hood seam, and I came up with 73 inches.

  8. Dan on May 30, 2018 at 9:10 am

    No worries, Andrew.
    The reason why I asked them, and here, is that sometimes the manufacturer even posts it on the official website.
    Thanks for going through all the trouble, Rob!

    So, there’s that extra inch I was talking about, but it’s still 0.228″ too short.. dammit!

  9. Boyan on September 19, 2018 at 10:35 pm

    Being a spreadsheet freak I put together lots of comps of the Nitro and Cloud with WM, FF, Marmot, REI, MH, etc. With the exception of WM and FF, the Nitro was very competitive in the weight department, What the Nitro had going for it was nearly 4 extra inches of girth, which is THE thing I hate most about mummy sleeping bags. Trying to decide between the Nitro and the Cloud now, and waiting on the next 20% off sales to roll around. I like the concept of a zipperless bag where you can control coverage and girth to your liking, but am concerned about drafts.

  10. Johnny on January 20, 2020 at 10:24 am

    I’m a pretty lean 5’8″ male and I’ve always had sleeping bags that are too long for me. I was considering buying a womans Nitro 0 degree for winter use. Their website says the bag fits up to 5’8″… Any shorter males out there have any experience with the womans bag? Is there anything not obvious that I should consider about the womans version before purchase? Thanks!

    • Andrew Skurka on January 20, 2020 at 11:22 am

      I believe the women’s version is shaped differently, more width at the hips and less at the shoulders.

  11. Don on November 28, 2022 at 1:54 pm

    What’s your opinion about nitro 20 vs cloud 20? Which one do you prefer and why?

    • Andrew Skurka on November 28, 2022 at 2:05 pm

      Personally, I’d go with the Nitro, because I run cold, because I prefer to be warm, and because the Nitro can be better sealed against the cold than the Cloud.

      But some people really like the Cloud, because it’s less confining and because it stays on a pad better.

      Either way, I think both are good picks.

  12. Don on November 28, 2022 at 5:49 pm

    Thanks for the reply Andrew.
    So seems like Nitro can do everything cloud can do (if used with zipper off) and more? Since it will 100% seal you in and prevent drafts?
    What would be the pros of cloud over the nitro?

    • Andrew Skurka on December 28, 2022 at 5:38 pm

      The cloud has a sheath on its underside, for the sleeping pad. So you’re less likely to roll off your pad with the Cloud. Also, some people just absolutely hate the mummy sensation, so they’ll accept draftiness in exchange for some freedom of movement.

  13. gary on April 27, 2023 at 1:41 pm

    Is the 800 fill-power PFC-free water-resistant DriDown in the Nitro 35 bag goose or duck down?

    • Andrew Skurka on April 27, 2023 at 1:52 pm

      Uncertain if duck or goose. And I’m also uncertain if it’s a difference that makes a difference — I can’t recall hearing a brand or an end-user touting the benefits of one over the other. What is motiving your question?

Leave a Comment