DownTo1 Packs

The engine's answer

Best side sleepers sleeping mat in frosty nights near −5 °C, under €400

Robens

PrimaCore 90

A thick, warm self-inflating mat for people who have given up on grams.

  • Very high R-value and 9 cm of thickness
  • Self-inflating and extremely comfortable
  • Tough enough to be careless with
  • Well over a kilo
  • Enormous packed

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

Why it wins, in numbers

Robens PrimaCore 90 is the sleeping mat the engine picked for this trip: €130 and 1.10 kg, R-value 5.8, a 92% match on the questions asked. The kit around it comes to €355 of the €400 ceiling, leaving €45.

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 43 L, and €400 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.

4.50 kg on your back · €355 of a budget of €400

Tent
3F UL Gear Lanshan 2: €130, 1.10 kg, Season rating 3, 50% match.
Sleeping bag
Forclaz MT100 15 °C: €35, 800 g, Comfort rating 15 °C, 28% match. Flagged: Not warm enough for these nights.
Sleeping mat
Robens PrimaCore 90: €130, 1.10 kg, R-value 5.8, 92% match. Strongest on: Sleep style.
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.

  • Naturehike R5 InsulatedA high R-value on paper for a remarkably low price.Naturehike R5 Insulated — €80, 750 g — gives up Thickness: 7.0 cm against the winner's 9.0 cm. It scores 69% to the winner's 92%.
  • Alpkit Cloud BaseWinter-capable warmth at a price that undercuts everything comparable.Alpkit Cloud Base — €130, 730 g — gives up Thickness: 7.0 cm against the winner's 9.0 cm. It scores 69% to the winner's 92%.
  • Robens Vapour 60A warm self-inflating mat for people who distrust air mats.Robens Vapour 60 — €110, 900 g — gives up Thickness: 6.0 cm against the winner's 9.0 cm. It scores 64% to the winner's 92%.

Questions this trip raises

How much does the whole kit cost?
€355 for all four items, €45 under the €400 ceiling. Prices are indicative euro list prices; the shops set their own.
How much does it weigh?
4.50 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 Robens PrimaCore 90 warm enough on the ground at −5 °C?
Its R-value is 5.8. For nights near −5 °C the engine requires at least 4.5, 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.