Hello-
You know, this really depends on the tent, your bag set-up, whether or not you’ll be using a bivy, and most of all, what you consider to be 4 season conditions. So I can’t give you a clear answer but I can tell you that the “3 season” and “4 season” guidelines on tents are somewhat arbitrary. However, there are typically greater differences than expense.
When considering traditional double wall tents, the differences typically are in fabrics used, fly coverage, and pole configuration. If you look at catalogs from any of the big companies, you’ll usually see more mosquito netting used on the inner tent in a 3 season tent. This improves ventilation on hot days but also allows greater airflow and can let spindrift get inside your tent in nasty conditions.
Next, “4 season” tents usually have a fly that goes all the way to ground-level which is very important in snow or high wind conditions.
Last, an increased number or more robust poles typically means that a tent can better handle snow loads, especially if the poles cross or interlock.
But the bottom line is that you need to look at the conditions you’ll call “4 season”. If you’ll be below the treeline in a more temperate climate, most 3 season tents will work. Pitching a tent in the middle of heavy snowfall with high winds, though, and you’ll be looking at a different tent. No one takes a “3 season” tent to the Himalayas. :-)
I invite you to take a look at our recent release of Bomber tents to see what an ultralight “4 season” tent might look like and start your search from there. The forum that follows the release might also have some good tidbits for you.
Best of luck-
Doug Johnson
Shelter Systems Editor