DownTo1 Packs

The engine's answer

Best down sleeping bag in frosty nights near −5 °C, under €1000

Sea to Summit

Spark SpIV

Winter warmth at a weight that should not be possible.

  • Comfortable near minus ten under 900 g
  • Packs smaller than most three-season bags
  • Excellent for fast winter trips
  • Very expensive
  • The close fit is restrictive when wearing layers

Find it at Bergfreunde · Trekkinn · Decathlon · Alpinetrek · eBay (used)

Why it wins, in numbers

Sea to Summit Spark SpIV is the sleeping bag the engine picked for this trip: €600 and 850 g, Comfort rating -8 °C, a 83% match on the questions asked. The kit around it comes to €870 of the €1,000 ceiling, leaving €130.

What the engine asked for: a sleeping bag rated to −7 °C or lower, a mat with an R-value of at least 4.5, a pack of at least 42 L, and €1,000 for all four; anything that falls short of these is flagged beside the item.

The kit it belongs to

Four items chosen together, not four separate winners. Swapping one moves the others.

4.20 kg on your back · €870 of a budget of €1,000

Tent
3F UL Gear Lanshan 2: €130, 1.10 kg, Season rating 3, 50% match.
Sleeping bag
Sea to Summit Spark SpIV: €600, 850 g, Comfort rating -8 °C, 83% match. Strongest on: Fill.
Sleeping mat
Naturehike R5 Insulated: €80, 750 g, R-value 5.0, 50% match.
Backpack
Forclaz MT100 Easyfit 50: €60, 1.50 kg, Capacity 50 L, 50% match.

What the runners-up gave up

Each of these still leaves a kit that closes — the budget holds and the pack shuts. This is where each one lost.

  • Cumulus Panyam 600The Panyam taken into proper cold, still at barely a kilo.Cumulus Panyam 600 — €500, 1.05 kg — gives up Packed size: 7.5 L against the winner's 5.5 L. It scores 76% to the winner's 83%.
  • Mammut Perform Down −7 °CAlpine-leaning down with a shell built for damp bivouacs.Mammut Perform Down −7 °C — €400, 1.05 kg — gives up Packed size: 7.0 L against the winner's 5.5 L. It scores 74% to the winner's 83%.
  • Mountain Equipment Helium 600The Helium carried through to winter.Mountain Equipment Helium 600 — €560, 1.08 kg — gives up Packed size: 7.0 L against the winner's 5.5 L. It scores 74% to the winner's 83%.

Questions this trip raises

How much does the whole kit cost?
€870 for all four items, €130 under the €1,000 ceiling. Prices are indicative euro list prices; the shops set their own.
How much does it weigh?
4.20 kg base weight — tent, sleeping bag, mat and pack together, before food, water and clothes. The pack is rated to carry 16 kg comfortably.
Is Sea to Summit Spark SpIV warm enough for −5 °C nights?
Its comfort rating is -8 °C. For nights near −5 °C the engine requires a rating of −7 °C or lower, which it meets.

Change an assumption

This page answers one trip. Yours is not that trip — adjust the nights, the budget or the company and watch all four re-rank.

Build my kit

Specifications are manufacturers’ own published figures and prices are indicative, not live. Comfort ratings and R-values are comparable across brands but describe a standardised sleeper on standardised ground — neither is a promise about you on a particular night. Check the current spec and price with the retailer before buying.