That is the pitch circle diameter and number of bolts. You need 5x114.3, 5x120 is bmw or commodore or others.
Edit: what are you trying to achieve? Tyres flush with the guards or just wider tyres? If I was starting again I would go 18x8.5 with 35-40 offset and run 235/40 tyres. When my yokos wear out I will fit 235s but the reduced offset gives a bit more track width and fill the guards. 245/40 is probably not legal depending on state regulations, not legal in Q and most states run similar words. 245/35 has less sidewall than 225/40.