Thermarest Neoair X THERM v.s. NEMO Tensor 20 R

Gotta say up front I’m no fan of Neoair mattresses, having owned  a 1st gen. one and returned it to REI after one night at 9,000 ft. No fun inflating it at that altitude and when the temp dropped from 70 F. to 30 F. the mattress lost a LOT of loft.

Well, if the NEMO can defy the ideal gas law, that’s the way to go! :-)

I used a tensor for a few trips last year. I would say to compare the warmth to an xlite, not the xtherm. It is definitely a 3 season pad. Also, the mattress is not very durable. I used it only in a tent with a floor, and both mine and my boyfriend’s pads developed small, slow leaks that I could not identify despite a soap test and submersion test. I gave up on those mats and took them back. I loved the comfort and feel of the mattress, but something that delicate just isn’t practical for my use.

edit: just to be clear, I was using the insulated version of the pad. The uninsulated does still have a heat-reflective layer, giving it a modest boost in warmth. I stand by my assertion that the insulated tensor is more comparable to the xlite than the xtherm.

There is a few makers out there being not giving much away with the r rating. Have to think there’s a reason they are not saying what it is,

There is a Tensor and a Tensor Insulated – it is important to know which is being discussed.  It seems that it would only be fair to compare the Tensor Insulated against the Xtherm.

Nemo has a PDF explaining why they don’t use R-values. Make of it what you will, of course, but it might be interesting.

Never used a Tensor, but I’ve used an XTherm for a few years now. No issues, warm in winter (with a very thin foam pad under it), has held up well. When it dies, I’ll buy another one.

+1 Doug,

Hmmm… Nemo pads are “delicate”. Good to know.

I was giving stats on the insulated Tensor 25 R so I would get a better comparison.

I’ll look at my post over at those Communists on Trailspace to see what folks say. But it’s looking like S-THERM.

I have an old Nemo Astro Insulated pad, and I love it. I’ve lost track of how many nights I’ve used it, but it’s probably 50 nights with no leaks or issues. I’s a heavier pad, so now I use a Thermarest Xlite for backpacking and save that for camping. I find it to be a lot more comfortable than my Xlite. It’s hard to explain, but the shape and stretch of the baffles makes it more comfortable than the Thermarest which ends up being fairly flat and rigid if I inflate it enough to not hit the ground. It helps that the Nemo pad is thicker. The Astro Insulated has a layer of Primaloft insulation, and I find that it and the Thermarest pads have similar warmth in 3 season conditions. The Tensor pads would be interesting if they have some of the comfort of the heavier Nemo pads.

I’ll echo what Heather mentioned. I would compare this more with the warmth of the X Lite. Never owned a neoair but had an Exped UL7 before switching to the Tensor Insulated. The Tensor is definitely not comfortable down to 15. I’ve taken it to about 25 F and started to feel a chill from underneath. Add A bit of CCF though and you should be able to push it.

Overall I’ve really liked this pad. Its definitely the most comfortable pad I’ve owned. I’ve been super finicky and undecided about pads, but this one has made me stop looking around for others.

Michael, how does the warmth of the insulated Tensor compare to the UL7? Why did you switch from the UL7?  Warmth or comfort? The Tensor does look very comfortable.

The tensor is really quite comfortable. The fabric feels good against the skin, the surface is stable, and it is very quiet.  The dimpled surface I found much more comfy than the baffles of the exped. I was in love with it, the durability issues broke my heart a bit.

I have been using the insulated S2S ultralight and have been largely pleased, it is sturdy and easy to inflate and pretty comfortable, if not quite as dreamily comfy as the tensor.

Seems many people had durability problems with the Tensor versions. THAT I don’t like.

well some folks have had issues with the xlite/xtherm as well …

of course thermarest will take care of you …. theres been posts on BPL how they replaced even decades old prolites

;)

Thanks to a pretty big modification project I undertook on my Tensor (cut/reshape, remove all insulation and replace with 850FP DWR down), I can tell you exactly how much Primaloft is in the 25L Insulated version:

2oz.

There is a reason they’re not publishing R-values. I suspect to 20R contains closer to 1oz.

Anecdotally, I had it out (pre-modifications) on an appox. 35F night and woke up with a cold back while using a 20F quilt. Frankly, I find the “good to 15F” claim to be downright irresponsible and unsafe.

That said, I love mine (especially after my modifications – it has over 3oz of down now, and is definitely warmer). I can’t sleep on a NeoAir thanks to the baffle deisgn, which stretched my lumbar area too much (the fully horizontal baffles mean the weight from my hips makes the air press up a whole lot under my lumbar, and I wake up with a super sore back). I find the Tensor much more comfy.

Well, if the NEMO can defy the ideal gas law, that’s the way to go! :-)

^^^^^^LOL  ;^)

Boyle is chuckling in his grave.

I did a little more looking at the Tensors.  There is a “Field” version which may be a better comparison to the Xtherm.  The field version has double the Primaloft insulation (3oz vs 1.5oz for the 20R size) of the regular insulated version, and is consequently rated a little warmer at 10-20F.  It is 18oz vs. 15oz for the regular insulated Tensor, due to the extra insulation and 30D bottom instead of 20D.  The Tensor Field version seems to be a more even comparison to the 17oz MAX Xtherm, though it may still not be as warm.  Of course there are still other differences – pad thickness and comfort, noise level, and the Xtherm uses 30d/70d fabrics instead of 20d/30d on the Field.

Note that the weight listed for the Field is not correct.  The oz are wrong even though the g are right. It is even wronger on REI’s site.  I checked with Nemo:

<span style=”font-family: ‘Calibri’,sans-serif; color: black;”>Hi Stephen, </span>

<span style=”font-family: ‘Calibri’,sans-serif; color: black;”>Thanks for your email regarding the weight of the Tensor Field. You are correct, there is an error on our website regarding the weight. The true weight of the pad is 17.98 ounces, or 510 grams. I will work with our web team to correct this error. </span>

<span style=”font-family: ‘Calibri’,sans-serif; color: black;”>The Tensor Field has a better insulation rating because it uses almost double the amount of primaloft insulation compared to our regular Tensor Insulated pads. This pad was designed to pair with some of our cooler weather integrated sleeping bags, so we felt that more insulation would be important in this item. Please let us know if you have any other questions!</span>

Edit: I had stated that the regular (mummy) XTherm was 17oz, but it is the XTherm MAX (full rectangular cut) that is 17oz.