inner tube width range relative to tire width: reliability effects? [Apologies if this seems like a dup: I see there are lotsa tire+tube questions, but this one does seem to be slightly different, in that it strives for generality and concerns choice between alternatives.]

question

Suppose one is buying tubes for a given {rim, tire} tuple. Assume the following data/constraints:


The tire fits the rim's bead seat diameter (BSD) appropriately and has tire width w1.
Tubes ta and tb match the rim/tire BSD and are identical in all meaningful1 respects except width: identical cost, material, thickness, valve, etc.
ta specifies a width range w0-w1 (with w0 &lt; w1)
tb specifies a width range w1-w2 (with w1 &lt; w2)
One is a competent tube changer with lots practice.
One's primary concern is tube reliability over time: i.e., one very much wants to have fewer flats.


Given the above,


Are there empirically-valid reasons to choose ta (i.e., the tube for which the tire width is at the high end of the tube's width range) over tb (i.e., the tube for which the tire width is at the low end of the tube's width range), or  tb over ta? Or is there no reason to prefer one over the other?
Are there other data/constraints which are significant for the decision? E.g., whether one typically runs at high or low tire pressure?


motivation

I drive recumbents with 20-in/406-mm front wheels, currently running unbelted 20x1.35 Primo Comets. (FWIW


tire make/model is irrelevant for the rest of this question, so feel free to ignore.
I don't drive a trike: I have 2 nearly-identical SWBs with swappably-identical wheels. I like to have spares :-)


) I bike for transportation, so reliability is very important to me. Unfortunately


I recently moved to an area with much more puncturing road debris.
The area is also less dense, causing longer mean trip distance which exposes me to more debris.
Recent flats have now consumed my stock of 20x1.35 tubes. FWIW, I replace tubes rather than patching them (assume that preference as given :-), and I like to keep a few spare tubes (as well as ... everything else).


Fortunately there are some 20x1.5 Kevlar-belted Comets locally available at a decent price, which I intend to try. However the 406-mm tubes I'm seeing (and on which I now need to stock up) are either 20x1.25-1.5 or 20x1.5-1.75. Which raises the more general question.

possible answer

I bought the 20x1.5-1.75 for the Primo belted Comets. After 3 months: no problems installing, no flats, hold air well (i.e., takes a long time to go from 90 psi to 80 psi). Granted, this is not much of a test: n=1, not enough time for testing, change of tires is a confounding variable. But WTH.



1 Assuming both tubes have the same material and thickness, the wider tube will be heavier, but consider the mass difference negligible. (In this specific case, the mass difference=26 g, which is negligible for me.)
If you're getting flats regularly, my guess is that its not the tube's fault, but you to need to make sure that you have sufficient tire pressure and switch to puncture-belted tires (e.g. Schwalbe Marathon). A tube is just a balloon, and you can often put a tube marketed for a not too different size tire into one which slightly different without problems (so long as you don't have the extra width bunch up; e.g. don't put a 29x2.5 tube in a 700x18 tire; I normally do this with 700x23 marketed tubes in a 700x28 tire without problems). Just like most balloons, even the smallest prick will deflate it, so you really need to protect the debris from getting to the tube in the first place. The thickness difference between the rubber in the bigger and smaller tubes will likely be too small to make a difference. And in this case, since the tube is designed to work for tires of your size in both cases, you should expect to have perfectly acceptable behavior with both sides (that is, dumb luck should determine which works better). 

Empirically, if anything, the brand of tube might have a slight effect. I've had bad luck with tube reliability from one manufacturer in particular, so I don't buy their tubes anymore.

If you're really paranoid, they make tubes which have extra thick rubber called puncture resistant tubes (useful if you have goatheads) and you can fill your tube with tire sealant (Slime). These will be more resilient to punctures compared to other tubes, but they are more expensive and Slime is messy. But I'd start with some puncture resistant tires. In short, if you don't have these speciality tubes, its likely the case that it doesn't matter which tube you have. 

I'd suggest avoiding using tire liners, since they can actually increase flats unless you're really not in good shape. A puncture belted tire is a better idea for most people.