Interestingly, the manual for this car (which is close to 40 years
specifies a rather wide variety of grades for this car. I have to
they were vastly different in 1970 so I pay it no mind.
Everyone always said "10W-40" as the default response for that car.
Can 0W-40 be anything (significantly) different other than it's
at cold temps? I think of 10W-40 and 10W-30 (which I've used
in the past as well) as identical at cold temperatures.
Speaking of temperature, about how hot DOES this kid of car run?
talks about cars "running hot" these days. Is this relative? Did
"run hot" back then? This is a 500 CI motor after all. I just don't
I've used 15W-50 Mobil-1 synthetic and other grades of conventional
(10W-30 up to 20W-50) before. None produced any ill effects that I
report. The engine does leak oil to a degree and none of those oils
it better (or worse). My real question is would 0W-40 make for easier
in the cold? I want to make the engine last (never have to rebuild
so synthetic is an option I'm thinking of returning to, and perhaps
is the right grade for every situation. But if people have other
I have found the posts so far very imformative: a big thanks to N8N,
and Ad absurdum per aspera.
Having had one of those glorious beasts Eldorado with the 500. . . I can say
they are particularly delicate motors. It was not one of GM's better
offerings. Neither was the pain on the Eldos, particularly the metallic. I
think the engine would do okay today if you had a new one and stuck with oil
like Castrol Edge. For some INSANE reason, it seemed like many people used
Pennzoil and Quaker State in those engines. By the time they had 50,000
miles they were full of sludge. Cylinder walls horribly varnished and
scored. They were blowing oil like mad by 65,000 miles. Seems like people
with other GM vehicles were not as prone to use that crappy Pennsylvania
oil. Don't switch. Use a major brand conventional oil. Like I said Texaco
and Shell have really good, inexpensive oils as does Union 76 and Phillips.
Stay away from the off brands and chain store oils. (K-Mart - Wal Mart etc)
House brands. Castrol makes really good oils too.
The 500 isn't a bad engine if you care for it properly. Like I said, if you
got a new 500 it probably would hold up well. GM engines of 1970 generally
weren't the best. That was a dark period for American cars in general.The
bad American cars of the 70's is why you see so many Japanese cars today on
our roads. Detroit was largely building "shit." The engines had all that
emissions crap on them that really didn't work well and burned valves etc.
Rube Goldberg devises thought up by Ralph Nader types who had NO idea what
makes an automobile run. That is another reason Japan & Company got 55% of
the American car market. Japanese cars didn't have to have all that crap
sucking the life out of their motors.