Hi, this is a message that is not really model or year oriented but I' d like to hear what you know on the topic of unleaded fuel compatibility of older volvos. Say up to thE mid 80's.

On another forum I'm watching, someone claimed in one of these ever returning "will my 1978 car happily drink unleaded?" posts, someone claimed that in the mid 60's, the US asked the manufacturers to produce unleaded resistant engines from 1965 on because it was then a US gov intention to ban leaded fuel from 1970 on. Thus, the guy continues, all the valve and seats manufacturers started supplying unleaded units to ALL manufacturers in the world becaus noone would like to be left ouside the US market. So, he concludes, if your car was built after 1965, you automatically have hardened seats and no need to worry.

It's the first time I hear this theory and I gotta say I'm a bit skeptical about it... I've had 4 engines in my 121, ranging from the original 65 B20A to the present 1974 B20E I don't think any of these engines were designed to run unleaded. My knowledge was that all vintage volvo heads were all cast iron without and the seats are simply machined in the material.

Do you have any information that would confirm this 1965 switch from non hardened to hardened seats?

Thanks in advance, Séb