test

(function() {

	function Foo() {
		this.bigData = new Array(5000000).join("XXXXX");
		this.smallData = "bla bla";
	}

	Foo.prototype.m = function() {
		var smallData = this.smallData;
		$(window).on('click', function() {
			console.log(smallData);
		});
	};

	window.f = new Foo();
	window.f.m();
	delete window.f;
}());

vs

(function() {

	function Bar() {
		var bigData = new Array(5000000).join("XXXXX");
		var smallData = "bla bla";
		return {
			m: function() {
				$(window).on('click', function() {
					console.log(smallData);
				});
			}
		};
	}

	window.b = new Bar();
	window.b.m();
	delete window.b;
}());

vs

(function() {

	function Bar() {
		var bigData = new Array(5000000).join("XXXXX");
		var smallData = "bla bla";
		return {
			m: function() {
				$(window).on('click', function() {
					console.log(smallData);
					bigData += "X";
				});
			}
		};
	}

	window.b = new Bar();
	window.b.m();
	delete window.b;
}());

vs

(function() {

	function Bar() {
		var bigData = new Array(5000000).join("XXXXX");
		var smallData = "bla bla";
		return {
			m: function() {
				$(window).on('click', function() {
					console.log(smallData);
				});
			},
			n: function() {
				bigData += "X";
			}
		};
	}

	window.b = new Bar();
	window.b.m();
	delete window.b;
}());