j is the wheel width in inches. I'd take a look at 18x8.5 et45 (or 18x8 et40) if you want a chance of not rubbing with 15mm lowering springs. The general rule is around a 20mm further poke out before it starts to rub under heavy load. If you don't plan on using lowering springs you may be able to get a way with a bit more.
A forum community dedicated to all Honda Civic owners and enthusiasts. Come join the discussion about performance, modifications, engine swaps, troubleshooting, wikis, VTEC, and more!