Don't ask me. I'll just baffle you with bull!
Ah who gives...
The answer is 225/50x17 or 225/45 x 17. . Your current 225/60 15's give a 637mm loaded wheel diameter. With the 50's, it's 643 mm, and with 45's, its 634 mm. Go for whatever you can replace. I'd think 45's may be more common.
Here's
why:-
If you really wanna know the calculation steps, take
a)the wheel diameter in inches, multiply by 25.4 (17 times 25.4 = 431.8 mm)
b) the first reading on the tyre gets multiplied by the aspect ratio as a decimel. Then multiply it by two. (235 times 0.45 gives 105.75 mm. That's doubled, and you get 211.5 mm)
c) then add a to b, and thats 643.3 mm, which is the unloaded wheel diameter. Divide by 25.4, and its in inches (25.327 ")
d) divide that by 1.022 to get the loaded wheel diameter. Its normally 14 mm less at the base of the wheel. (643.3mm/1.022=629.45 mm, or 24.78")
Just some notes. My advice is free.
1.Look at the XF-BA Falcons that have the stance you like, and copy it!
2.In the old days of 14x7's on the front and 14X8's at the back, most XD and XF guys went for 245/50's (588 mm loaded diameter) tyres to slam them down at the front, and 265/50's (608 mm loaded diameter) at the back. This gave you a 21mm lowering job at the front, and stopped the a$$ drag that the coil sprung Falcs had.
3.Going to 17's allows you to shove the wheels further in wards at the front.
4.The greater the height of the total wheel combo, the more hassles you have with inner guards. Blackwood Fords (XD/XE/XF) were designed around a 644 mm tall tyre, or 630 mm tall loaded on the road.
5.The XD/XE/XF is crab tracked, with very little room for big bags up front. Front track is 1559 mm (61.4 ") but the rear is only 1527 mm (60.1 "). And the car has a tappered front section with very little guard cover in the front. XE's were much worse, the XF is better than this. XD's were almost as good. I'm sure the ADR guys who have to tick off the legality of an Aussie car before its sold must have told the Broadmedows guys to cover up the ER 60H15 Wildcats on the 1982 XE ESP...they stuck out like dog balls at the front.
6.So with an XF you end up with no room for 265's all round like you can with an XA-XC Falcon.
My pick is 235/45 17's on 17x8's, and 255/45 17's on 17 x 9's.
You'd need something illegal to pay for that combo.
My old XE has 235/60's ( 623 mm tall loaded on car) and 245/60's ( 636mm tall on car) on 14X8's all round. Did some quard work up front, though. When its lowered its gonna get close to doing the front gaurds in again.
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