I just started riding single-speed, and still have my 4-speed Atom freewheel on my C&V. I am using the 14T cog in conjunction with the 40T inner chainring (I took the 46T off). I want to select a proper single-speed freewheel.
What I was unaware of, was that most (all?) single-speed riders ride with both a lower-geared freewheel and a higher-geared chainring.
I know that switching to a single-speed freewheel will reduce weight, which is good.
I've read the single-speed advice article over at Surly, and have taken note of the important factors in efficiency; chain line, chain tension, chain selection and lubrication etc, but have yet to have-explained why a relatively high-geared freewheel, in combination with a lower-geared chainring, such as mine, is undesirable.
I love the gearing of my bike as it is, and don't want to change it at all.
Do freewheel gears larger than what I am using now translate into easier pedaling and/or less wear and tear on the drivetrain?
I found a high-quality freewheel (White Industries Eno) that is 16T, and if I use that and put the 46T back on the crank and take the 40T off, is that inherently better? How would 46/16 feel as compared to 40/14?

40x14 and 46x16 are identical (75-ish gear inches, depending on tire size), so your legs won't feel a difference. However, 40x14 will wear faster than 46x16 because there are 8 fewer teeth to spread the load. On the other hand, depending on your frame, you might have an issue with a 46t chainring clearing the chainstays.

Thanks, cal. That's good news about the gear/inches. The bolts on the chainwheel will clear the chainstay if I leave them where they are, but I'll have to put spacers behind the s.s. freewheel to push it outboard and give me a straight chain line. I use 700 x 28 tires.
I should note that the teeth on both my freewheel and crank are steel.

Go with the big gear inches man, to feel that tension in your legs, its a good workout

Steel, Aluminum, Carbon teeth or whatever, its make no different

As long as its straight, not too tight, not too loose, keep clean every after ride, well lube and change chain every approximate 3000km

Your drivetrain will be in good shape for a long long long time til you (probably) decided to change or buy a new bike

Thanks, Alt. I'll follow your advice. I noticed that on the afore-mentioned article at Surly, they indicated that "too tight" meant being able to feel any resistance when you back-pedal. I had to pull my rear wheel a bit forward, this morning, and now it is much better.