A flat 15 second quarter with a 1367 kilogram Falcon XD ( 1344 kilos with the alloy head), is in need of 190 hp with one person. That's easy to get on a carbed Falcon.
Top speed is 192 km/h (120mph) at 4800 rpm, as the Falcon XD has a drag factor of over 0.48, and has 2.25 square meters of frontal area. There are better council flats around with lower drag factors.
For speed and cruising, the 2.92:1 diff is best, with tyres the same height as the stock ER70H14's. Some 235/60's on front, and 245/60 's on back are okay if you want to be able to run over kerbs without making your alloys look like cheese singles.
The rev limit is 5400rpm.