Offset/spacers related generic BBK fitment wise trends
 

I don't care about 'flush' wheel setup, i don't want to go for wider/stickier tires, that might rub fun from car.
What i do care wheels wise - if i change them, i wish to get lighter ones for less unsprung & rotational weight, potential fitment of BBKs, if i'll decide to install them, possibly cheaper/more common tire types, and to not have something that will affect ride balance or will require expensive extra upgrades/parts to compensate (which as i've heard are needed to fix scrub radius issues).

16" rims seemed very interesting change. Except that they come with way more BBK fitment issues. Hence comes question:

Given of same models wheel rims that will be positioned in somewhat same place in wheel well, which will fit better bigger brakes - less positive offset + spacers, or no spacer but bigger offset? In which case less chance for BBK to touch spokes or rim inner concave surface for 'generic/most rims'?
If BBK manufacturer has listed some wheel rims of checked fit, which offset/combination for same model rim should clear these BBKs same as listed rims (for case if that rim is discontinued/rare and only available in different offset size vs one listed as fitting)

As example: Essex APR Sprint kit lists SSR type-c 16x7 +48 with 5mm spacer. If only offset & spacer changes, what other offsets for this rim & it's size will also clear this BBK for sure, and which not?

Using your example, anything with a lower offset than +43 (+48-5mm) or a bigger spacer than 5mm should fit. Keep in mind that the spacer pushes the whole wheel out, while a lower offset changes the shape and angle of the spokes, so you'd be best served by sending the AP Sprint template to the manufacturer you intend to buy the wheels from and have them check for you.

if i were you, i'd just stick with 17" wheels that are lightweight. this will obviously help with finding more options for BBK's and i personally think the small weight savings with a 16" wheel is a non-factor compared to the benefits of having a proper BBK instead.

Assuming the brakes don't call for a minimum wheel diameter, the ONLY thing that matters when it comes to brake caliper clearance is the wheel spoke design.

-alex

BRTG: small wheel weight savings on 16" vs stock width 17" .. maybe. But more i read about downsizing "upgrade" relative to this car, the better it seems in my eyes. Including better looks (for my taste), easier weight transfer, better dampening on bad quality roads and much cheaper rubber that can be burnt fast. More sidwalls flex/less precise turn-in may be fixed at some extend by rubber choice. If i switch from stock once, why not tick most checkboxes at that. BBK seems nice potential upgrade, but less urgent. I simply wish to leave brake upgrade option open, if i switch wheels, hence am a bit careful searching best alternatives. If worst comes to that, stock brakes with air ducting, aftermarket brake pads, steel lines should be more then uptojob for light track usage imho, and except Essex's there is also Wilwood kit, made to fit in stock rims (including 16" for 4pot, no?).