That was the main one, and also in case you ever ended up with car trouble you had a record of every place you had filled up and every time you had the car serviced. It was also financial: you could tell how much you were spending on gas, whether gas prices were going up or down, which stations had the cheapest gas, etc.
Nowadays a lot of this is recoverable from your credit card statements (though again, I don't know anybody who actually does this), but in the 80s you would usually pay cash for gas.
alt Hacker News
That was the main one, and also in case you ever ended up with car trouble you had a record of every place you had filled up and every time you had the car serviced. It was also financial: you could tell how much you were spending on gas, whether gas prices were going up or down, which stations had the cheapest gas, etc.
Nowadays a lot of this is recoverable from your credit card statements (though again, I don't know anybody who actually does this), but in the 80s you would usually pay cash for gas.