In my immediate area of NW Indiana, I lose the Chicago stations just as I hit the county line going into St. Joseph County (home of South Bend), around Demotte, IN in Jasper County, Roselawn or Morocco in Newton County. On the Illinois side, I usually lose Chicago stations going south of Manteno, with losing 100.3 around Peotone, due to 99.9's 50kw signal splattering over their station. Going north of Chicago, I usually lose Chicago stations once I get around Franksville (just west of Racine) on the Wisconsin side, while I usually use 97.1 in the middle of Lake County, IL, due to sister station 96.9 having more of their signal in Lake County, IL. On the Wisconsin side, the Chicago stations are usually still strong (around Kenosha), but many slowly get splattered by many of Milwaukee's first adjacents. As for Milwaukee stations, I can only speak of their Class B stations south of Milwaukee, & their stations have made it on my car radio up until around Zion, then I lose most of them. 100.7 & 99.1 are the only 2 Milwaukee area stations (100.7 licensed to Racine) that make it further than that, due to no first adjacents in the Chicago market on 100.5 or 100.9 for 100.7, & no 99.3 or 98.p for 99.1. I usually lose those stations once I get into Cook County IL., around Northbrook.
For South Bend stations, they have few Class B stations, & what few they have, I usually lose 92.9 once I get into Portage, once 93.1 starts splattering on their station. For 101.5, I usually can keep them even as I enter Gary, since there's no 101.3 or 101.7 in Chicago. If I lose them, it might be once I get around Hammond when the signal is weak, but still can hear something. With 104.7 transmitting out of Elkhart County, I usually lose them around Portage or South Haven. For most of their Class A's, I'm lucky if I even hear most of them outside of St. Joseph County, as most hold 3 or 6kw licenses, & most drop out once you reach Michigan City.
Lastly, for Lafayette Indiana stations, there are few stations licensed to that small market, & only 2 of them are 50kw stations. For the 2 50kw stations, they only make it as far north as Rensselaer or Demoote in Jasper County & Morocco in Newton County before they're hammered by Chicago stations. That would be 96.5 & 105.3. For their Class A stations, most can't be heard north of Tippacanoe County, due to the way most of their stations are laid out in the market, & their COL's.