I think that the two most important reasons why the 16 ounce wool is preferred (with the 13 coming in at a close second) has less to do with its warmth than it does its ability to hold its shape and the way that the mass of the fabric gives the kilt a notable "swish" (for lack of a better word) factor. Lighter fabric just doesn't do it as well as the heavier material.
You may find that the 11 ounce material tends to fly up more in the wind or as you're walking. The PolyViscose material used as an alternative to wool by USA Kilts, Canadian Casual Kilts and others is listed as being a 10-11 ounce weight fabric and hangs and moves very well but those of us who also have the heavier wool kilts can appreciate the difference in the weight. 11 ounce wool may work out all right but everything that I've read points to it not being ideal for a man's kilt.
I don't mean it as an admonition but only as a cautionary statement: better that a newbie takes his time and tries to get a first hand look at his fabric options before ordering than that he orders from a website or based on what he has heard on the internet. Lots of the companies will send swatches at a nominal charge. If you're plunking down the cash, you owe it to yourself to get something that you will be happy with.
Displaced 3rd generation Californian now residing in the "old" State of Jefferson, USA
Posts
4,186
Mentioned
0 Post(s)
Tagged
0 Thread(s)
Welcome to the board. My kilt is 16oz wool. I have found it to be comfortable in the high 90's and in the low 20's. The heavier material wears better than the lighter materials.
[I][B]Nearly all men can stand adversity. If you really want to test a mans character,
Give him power.[/B][/I] - [I]Abraham Lincoln[/I]
I prefer the hang and feel of a 16 oz though my 13 oz ones are perfectly fine too. As we have had such a miserable summer here in the UK the question of feeling too hot in the heavier kilts has not arisen!
[B][COLOR="Red"][SIZE="1"]Reverend Earl Trefor the Sublunary of Kesslington under Ox, Venerable Lord Trefor the Unhyphenated of Much Bottom, Sir Trefor the Corpulent of Leighton in the Bucket, Viscount Mcclef the Portable of Kirkby Overblow.
Cymru, Yr Alban, Iwerddon, Cernyw, Ynys Manau a Lydaw am byth! Yng Nghiltiau Ynghyd!
(Wales, Scotland, Ireland, Cornwall, Isle of Man and Brittany forever - united in the Kilts!)[/SIZE][/COLOR][/B]
from South Wales UK! 
Bookmarks