R Values, Big Agnes Air Core, Thinlight

You are more hearty than me. I notice cooling from the ground using an uninsulated air mattress (with quilt) at around 55F and wouldn't choice to use one below around 50F without additional insulation.

Will the GG thinlight help? Some. In my experience it will give you another 5-10F comfort depending on a variety of factors. It's not enough for me down to freezing.

Personally, I would much rather use the BA Insulated AirCore which is listed as having R4.1 insulation. So it's warmer, less bulky than the thinlight + plaineAirCore, and approx the same weight.

–Mark

Have a look at the chart that Exped have about their mats. They list all the usual specs , includig the R value and what they consider the corresponding minimum temperature for each value. (click the comparison link)
Franco
http://www.exped.com/exped/web/exped_homepage.nsf/b43HomePageE?openframeset

I've used the non-insulated Air Core at temps down to 30 degrees or so with a 15 degree bag and been perfectly comfortable. Below that I can feel the ground temp.
I wear thermals, socks and a cap.

Mark – it may be that I do get colder than I ought to below 50 on account of the uninsulated pad; and probably don't notice it due to how well my bag insulates. It would be nice to upgrade to the insulated air core, but rather not spend the $$ if I don't have to.

Franco – thank you for the link, very interesting. So if the Exped doc applies to me (and I know it will be different for different people on how well we stay warm at various temps), then even the GG thinlight may not be that helpful at 35, given the 1.5 R value mats listed with a min temp of 43.

Joe – appreciate your experience… my 32 bag leaves me cold at 32 degrees with just hte air core; and I'm pretty sure the cold ground is a big factor for me.

I'm tempted to turn in my air core classic for one of the new 11 ounce mummie shorties; maybe at the same time I'll order the insulated air core, although hard to part with my hard earned cash… Thanks for all of your thoughts on this.