When I was challenged to keep the British neutral in the First World War I pondered the long term impact. Painting broadly and waiving the hand freely I had the world effectively dominated by the USA, Anglo-Persian and German oil interests, the USA was a significant domestic producer, the Germans and British shared Mesopotamian oil and the British dominated Persian productions with interests in the Arabian peninsula at odds with Ottoman and also German and American interests. I imagined the Americans get into the Ottoman and by extension Arabian fields through partnerships with German interests likely under stress from the war. Recall that a lot of the oil we now take for granted did not come online until the 1920s and then 1940s or 50s or 60s. I have the Dutch playing a bigger role too, they can meet domestic demand and export, likely to both Germany and Japan here. The British likely export a lot to Japan and supply France. You have the Dutch (with American investment) refining Venezuelan crude, so the industry was already multinational and global in some regards. I set aside the prospects for an Anglo-Ottoman War or Pacific War, you can imagine your own divergences. By the 1970s I have the USA still a serious domestic producer with interests in many foreign fields, especially ones in the Arabian Gulf, but I have a much more potent BP as well as the new "German Oil Company" as a serious player as well as partner to American companies. Soviet oil might get serious investment from either British or German interests given detente or even big USA investment with no Cold War as we know it, even the Japanese might have moved to partner there as it really makes sense to ship Siberian crude and gas to them via Manchuria and the Korean peninsula. Thus you have a nicely diverse supply base, likely no OPEC but potentially the Ottomans command as much if not more oil reserves than modern Saudi Arabia. Here the politics could get you a sustained "cheap" oil era.
I say all that to underline that oil prices are a factor of production costs but also politics. The oil shock was as much about OPEC pressuring (punishing) the West as it was profits. In a world without the shocks you have altered course with who knows what further changes. But for the USA I would say the big gas guzzling car should remain dominant longer. Look at how we moved to big pickup trucks and SUVs. Buses really can compete with trolleys, trams and what we now call light rail. But another decade of pollution belching cars might bring CAFE, smog equipment and other pressures to change. The small car might yet become both viable and luxury land yacht killing as did high gas prices. Simply leaving gasoline at pre-1973 pricing may not avert the ascendancy of smaller cars or their manufacturers. Ultimately it should not be so simple.
In my pondered ATL oil ratchets up because the Ottomans are peers with both the USA and USSR as producers, Germany pursues alternatives for strategic reasons and weans away from petroleum while the USA does not, the British get caught in the middle after Iran rebels against the concessions, and I have the Germans stronger trade partners in the USA but Japan competing fiercely in the Commonwealth. Both battle in the lesser developed world. America has a robust domestic market still dominated by the Big Three. In the end I see the USA even more fat and happy really, essentially insulated from the global confusion, big cars are a bigger segment, trucks still overtake them, urbanites shift to smaller cars or even better public transportation in a denser urban landscape where the Federal Freeways are not funded. Its an America that feels more 1960s longer.