UltraLite

Over the last thirty years I’ve had nine camping mats and only one has failed, a Thermarest ultra lite one, and that was after five or six years of use. All brands, but mostly Thermarest.

The teal-green / purple Therm-a-Rest that was sold from the late-1980s into the early-1990s was the “Ultralite” series (sometimes just called the “Therm-a-Rest Ultralite 3-Season”). • Nominal thickness: 1 in / 2.5 cm • R-value printed in the catalogs of the day: ≈ 3.0–3.1 If you were to test the same pad today with the current ASTM F3340-18 protocol, the value would come out a little lower—about 2.4 – 2.6—because the modern test is stricter and reports lower numbers for the same amount of insulation. EN1355 Sleeping bag rating are determined using an ~R5 pad and that is a minimum R-Value for winter camping to achieve the warmth rating of your sleeping bag. The latest Thermarest XTherm NXT/NXT MAX models boast an R-value of 7.3, providing excellent warmth, while older models (like the original XTherm) had an R-Value of 6.9. The Therm-a-Rest LuxuryMap sleeping pad (mentioned below) has an R-value of 6.0.

Hi All. I've been using a Thermarest for my winter camping for ages now. I'm guessing it's from the late1980's or early 1990's for a couple reasons. One: the color. It's teal green and purple. Two: it's the style that has the outer sleeve and baffles so you can turn it into a chair, which was first introduced back then. I'm curious as to the R-value. Thermarest only says 'the older the pad, the less R-value it likely has', and that they didn't have an accurate way to measure back then. The reason I'm looking for R-value is because I've been using this pad with an egg-crate style foam pad for my winter camping, but this thing is huge. It doesn't fit in my backpack, and I'm headed to Vermont and space is a factor this time. I'd have two other inflatables. A Sea-to-Summit that's supposed to be R 3.4, and an Alps Mountaineering that says R8.0 The last winter trip I did, temps were 18 degrees F the first night, and I was fine, then 5 degrees F the second night, and I was cold around my shoulders until I put my down jacket between the sleeping bag and sleeping pads. I hate being cold when I sleep, and have always assumed the giant Thermarest was giving me the best R-value, but the concern about space led me to start looking at how warm it actually is. I'm also anticipating temperatures to get below zero in January in Vermont. So... has anyone camped with an old Thermarest and a new sleeping pad? If so, can you share which is warmer? I guess I could always set up a tent in the backyard and do three nights with each pad, but ugh.

Thank you!! My googleability is subpar, lol. I also had no idea that sleeping bag ratings use an R5 pad. I know all about 'comfort rating' v. 'survival rating', but it's crazy that I've never come across this info. I'm enormously skeptical of the claims for the Alps sleeping pad (8.0), but it was on sale and I had a 50% offer from REI. I may still set up one night just to see what I think of that one. I haven't used it yet. I've only used the Sea-to-Summit in temps around 40 degrees. I suppose I can always come back in the house if I'm truly miserable, though it feels like 'the tent is up, you have to stay here'. Hahaha.

I have some semi-scientific details to share. I set up a tent in the backyard, and took the egg-crate foam pad, the Thermarest, the Alps and the Sea-to-Summit pads out for a spin. I have a North Face bag, for which I don't have a rating. It was given to me by an old Scoutmaster and has nothing to indicate suggested survival temps, but it's big - even compressed it takes up about a third of my 65+ liter pack. I set up with the foam pad on the bottom, then put each of the other sleeping pads on top, then laid on them - in the sleeping bag and flat on my back - for 20 minutes each. As soon as I got up, I measured the surface temperature where the center of my back was with an infrared thermometer. The results are as follows: Therm-a-Rest = 73.2 degrees F Alps R 8.0 = 59.0 degrees F Sea-to-Summit Etherlite R 3.4 = 64.2 Clear winner for Vermont. I'll just have to make the space for it. As for comfort, the thicker inflatables (Alps and StS) are nicer for side sleeping, with the Alps being marginally better since it's about .5 inches thicker. My hip never hit the ground, even when turning and having the majority of my weight on that single point. However, it's also about .5 inches more narrow, and I like every bit of extra width I can get for turning over and not falling off the pad. I'll give one of the inflatables to my daughter to take to Death Valley when she goes.

I have one very similar to this, and it’s actually the warmest sleeping pad I have. It’s huge, though. Only good for car camping.

Thick foam ridgerest with a 1999 version of an ultralight thermarest. which is thin foam and a little bit of air. the ridgerest is huge but only 511 grams., the thermarest packs down to the same as a nemo tensor. I tried the nemo tensor. the back rapide sl. also both of those on top of a nemo switchback. my thermarest on top of the nemo switchback. anything to cut bulk or weight. I tried so hard. but the only thing that didn't hurt my back was my original set up from 1999. I just have too big a butt/ curves to accommodate. I have to let out too much air to get support in the arch of my back.

I hate inflating a 3" thick mattress; maybe often not worth the trouble vs a very old, 1-inch "ultra-light" thermarest pad. (amazing durability).