ThePackRat

Talking exclusively about your basic steel wheel here ... the ones you slap wheel covers on.

What year did the big cars stop using 15x6's & start using 15x7's as standard equipment ?.

I'm pretty sure I've seen a few discussions the last couple of years ...

Where I recall 15x7's having been mentioned as being the standard wheel on the 77 & later cars and quite possibly the 71-76 cars as well.

I was always under the impression that a 15x6 wheel was generally what was standard in most cases ...

While the 15x7 only came into play if the car in question was a HD suspension/towing/police etc spec car.

And while I won't swear to it that I didn't miss it .....

I thought I even tried snooping thru 1980/1984 Olds FSM's at some point & don't recall seeing the factory steel wheel width being mentioned ...

Which I thought was rather odd.

J-(Chicago)

My 75 impala had 15x7 steelies. Whether they were original or not, I couldn't say.
It did have a tow hitch, albeit a crappy one.

orange442

I pulled a set of 4 15x7's off a 77 or 78 full size wagon with 403 and tow package.

ThePackRat

Forgot I had some Pontiac stuff kicking around here.

In this case ... looks like either 15x6's or 15x7's could have came as standard equipment depending upon options/trim.

1st page taken from - 1978 Pontiac FSM.
2nd page taken from - 1979 Pontiac FSM Supplement.