The toughest tents are commonly marketed for 4-season use. Why not the toughest sleeping bags? Well, until the UltraLite, it was hard to imagine that a single sleeping bag could be both warm enough for winter and cool enough for summer. The UltraLite pulls this off with 17 oz of premium 850+ FP down for colder conditions and a continuous horizontal baffle design that lets you move those feathers to the underside of the bag to vent excess heat on warmer nights. To enjoy this impressive versatility you have fork over some serious cash, and there are mild drawbacks in weight and packed size. However, in the hands of an experienced backcountry traveler, this bag's usefulness extends throughout the calendar year.
Western Mountaineering UltraLite Review
Compare prices at 2 resellers Pros: Best-in-class warmth, legit draft collar, light weight, exceptional loft
Cons: Really pricey, kind of bulky, awkward hood closure
Manufacturer: Western Mountaineering
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Our Analysis and Test Results
If your budget lets you shop for the absolute best backpacking sleeping bag, you will likely end up with a choice between Western Mountaineering and Feathered Friends bags. You basically can't go wrong. But to help you out a little, the UltraLite sets itself apart with a legit draft collar that ensures you can seal all your body heat in on colder nights.
Although it doesn't receive a third-party EN temperature rating, our testers believe the UltraLite is one of the warmest 3-season bags we tried. Its 17 ounces of 850+ fill power down seem to supply more warmth than bags with 20°F EN lower limit ratings. This superior performance is partly due to its substantial draft collar. When cinched closed with the internal drawstring, this collar was comfortable and effective at sealing heat inside the main compartment of the bag.
Some testers, however, consider the same collar to be unnecessary weight for most 3-season temperatures. Maybe so. But in colder spring and fall conditions or at high altitude, you won't have to worry about staying warm. The inclusion of the draft collar also arguably extends the UltraLite's usefulness to mild winter applications.
Despite providing best-in-class warmth, this bag weighs in at an impressive 1.86 pounds for a size long. Although this leaves it near the bottom of the full backpacking sleeping bag field, it compares favorably with bags that provide similarly high levels of insulation.
For cold nights, we consider the extra ounces of the UltraLite to be well worth the weight. Its overall warmth-to-weight ratio is also among the highest we've seen.
Unfortunately, the UltraLite does not offer quite the same comfort as its outstanding Western Mountaineering relatives. Sure, it can boast the same cozy down and soft ExtremeLite fabric, but its narrower dimensions don't provide the same spacious comfort.
These dimensions, however, are similar to most of the other standard mummy bags we tried. The UltraLite would thus earn an average comfort score were it not for its gentle, cloud-like loft that caused us to give it an extra point.
A common consequence of lots of warm insulation is a larger packed size. The UltraLite is no exception. Using an aftermarket compression sack we were able to squeeze this bag down to 8.7 liters in total volume. This gives it one of the largest packed sizes in this review.
Shoppers should keep in mind, however, that per liter this bag offers unrivaled warmth. Moreover, the difference between the biggest and smallest bags in the backpacking sleeping bags review was not especially large. When compared to its more distant competitors in the budget backing sleeping bags, the UltraLite and all the other bags in the standard backpacking review are relatively small.
This bag owes its superior versatility to its horizontal baffle construction, a full-length zipper, and an effective draft collar. The horizontal baffle construction means that its down insulation is sewn into fabric tubes, or baffles, that are perpendicular to the length of the bag. These baffles are continuous which allows you to shift the insulation to the top or underside of the bag depending on conditions. On colder nights moving more feathers above your body will ensure more heat is trapped inside. In warm conditions, do the opposite and shift feathers below your body to allow excess heat to escape. You don't have the same option with vertical baffles or synthetic insulation.
The full-length zipper also gives you another way to vent excess heat and be more comfortable on warmer nights. The substantial draft collar, in contrast, can cinch comfortably over your shoulders to prevent drafts from drawing heat out on colder nights. Together these features result in a bag that has the flexibility to stay comfortable across a wide range of temperatures. Its only drawback in terms of versatility is its down insulation which is inherently bad at insulating when wet.
Features and Design
Although the UltraLite lacks many of the fancier features of other bags, simpler is sometimes better. The absence of an organizational pocket or additional venting zippers helps this bag save weight.
Meanwhile, its only arguably unnecessary feature, a functional draft collar, is the defining characteristic that sets it apart from its closest competitors in terms of warmth and versatility. Thus, when you consider both the features this bag does and does not have, its overall design makes more and more sense.
Western Mountaineering doesn't give the outstanding performance of the UltraLite away for nothing. In fact, this bag is one of the most expensive 3-season bags we've seen. For the price, however, you receive a quality bag that's made in the US of A. And like the other ultra-premium bags, we believe the UltraLite is actually a great value when you factor in the weight and performance benefits you get to enjoy over its 10+ year lifespan.
In a field filled with 800+ fill power down bags, the UltraLite stood out to take home our Top Pick Award for Colder 3-Season Conditions. It achieved this by offering best-in-class warmth in a bag that was also comfortable, versatile, and low weight. Its biggest drawback is its astronomical price tag. If cared for properly, however, it could last for a decade and ultimately become a decent value. So if you're in the market for a 3-season bag that's up for the harshest conditions, you can't do any better than the UltraLite. If your backcountry travels occur in tamer temperatures, you might be happier with our Editors' Choice or Top Pick award winners.
— Jack Cramer