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Thermarest Xlite Warmth Over the Years?

Posted: Sun Jan 23, 2022 9:55 pm
by Chrisps
Have Neoair Xlites got warmer over the years? They are currently listed as an R value of 5.4 under the new ASTM system.

I've got a 2013 vintage Thermarest Neoair Xlite, which is a great mat and despite a lot of patches is showing no signs of giving up the ghost.

However, when camping (even in the height of summer), I generally get quite cold at night (with an appropriately rated quilt) and often end up wearing a baselayer, fleece and down jacket in my quilt.

I've always put this down to being a cold sleeper... but last weekend, I did my first winter bikepack... normally when I have camped in winter, its been on foot, and I have always taken a closed cell foam mat to double up with the xlite out of habit. Obviously couldn't do that bikepacking, because I couldn't figure a way of carrying a CCF mat on the bike. Overnight, despite being in my -9 comfort bag, I was pretty cold, and could really feel the cold through the mat.

So that got me thinking. At home I'm not a cold sleeper at all, and I don't remember being that cold many years ago on my old Exped Synmat (that the Xlite replaced). So could it actually be the 2013 Xlite is just not very insulative? But the current ASTM value of 5.4 is pretty high.

So have the Xlites got substantially warmer somehow (different internal design maybe?) over the years?

Note that I always run the Xlite at pretty much max pressure, always inflated by pumpsack, so its not moisture or suboptimal inflation causing a problem.

Re: Thermarest Xlite Warmth Over the Years?

Posted: Sun Jan 23, 2022 10:06 pm
by woodsmith
Thermarest changed the way their pads are tested and rated a couple of years ago. I emailed them about this at the time as I was about to buy an x-therm and the new model with the new valve had a significantley different rating. I was was told that the construction hasn't changed. I assume this would also count for the xlite.
I can highly recommend the x-therm. Its substantially warmer than the xlite which always seemed cold to me.

Re: Thermarest Xlite Warmth Over the Years?

Posted: Mon Jan 24, 2022 9:35 am
by Bearbonesnorm
It's simply a rating change. Some mats have gone up and others down.

Re: Thermarest Xlite Warmth Over the Years?

Posted: Mon Jan 24, 2022 11:21 am
by Chrisps
Yeah, realise that the ASTM was just a ratings change... I was wondering if the Xlite had been improved over the years to actually make it warmer. I.e. before the rating changes, was the pad actually more insulative than the original model that I have?

I had a thought while typing this that I could use the Internet Archive to compare the Thermarest site from 2013 with the site in 2019 before the ASTM changes... and the answer is that they are identical (3.2 on the old system). So I guess I have my answer; they haven't changed in any meaningful way

Woodsmith, its interesting that you find the Xtherm much warmer, that's useful to know! Maybe I need a new mat :sad: