Okay, let's put the Fw 190 on a diet.
F-W says that the BMW 801 powerplant will be heavier by 456 kg than the DB 605A powerplant for their spin-off of the Fw 187. Divided by two, difference of 278 kg. The 801s on the Fw 187 weight breakdown notes that two 801s will weight 2108 kg, with trapped fuel an oil. Armor is noted as weighting just 39 kg for the twin 801 installation, ie. ~20 kg per engine, however on the Fw 190 one engine there was 78 kg or armor for the oil system. If the 187 was projected to have the same armor as the Fw 190, the weight difference would've been up by ~120 kg.
The weight breakdown for these projects also notes the lower weight needed for the wing and U/C for the DB version, FWIW.
Back to a single 801 vs. 605A.
278 + 58 (= 78-20) = 366 kg weight reduction. The 605 allows for the motor cannon, so the MK 108 is installed instead of the cowl MG 131s and outer MG 151s. Less weapon drag
even than what the D-9 had. Main gain is reduction of weapon-related weight (guns + ammo + mounts etc), circa
300 200kg, at least
going by this table. Or probably
250 150 kg in case the cowl guns are the MG 17s? Compared with Fw 190A-6, were down by some
600 500 kg of take off weight, clean, mostly thank to the engine change - not a minor save vs. a 4100 kg fighter.
Now undercarriage - our brave new fighter will not be lugging around heavy bombs, so introduce a lighter U/C, with smaller wheels and a bit shorter legs. Instead of 258 kg, we might probably go down to 200 kg? Yes, I'm shamelessly copying what the NAA did here.
A 15% weight reduction allows us to cut the wing area by 15%, while keeping the wing loading the same. I'd try to get rid off the central - ie. the thickest - wing section by some 12-13% worth of span. Wing assy of the 190A8 weighed 475 kg, so here we can also save another 50-60 kg, and some drag, too (wing-related-drag on the Fw 190D-9 was significant 37% total drag - a new spanking low-drag wing on the 190/152 line certainly had a place here).
We'd be getting the lower wing- and weapon-related drag even when compared with the 190D-9 here, and probably the lower cooling drag. Weight save will be amazing vs. Antons and Doras, and wing loading will not be worse. Mileage will be much better.
edit: haven't accounted for the MK 108 + it's ammo weight in the 1st go; still a 600 kg decrease vs. the 190A-6 with lighter wing accounted for