Hello, would there be some good current options for recommended oil for 1975 Eldorado 500 CID GM engine? Mileage is at 50K (original!). Owners manual just says "good quality SAE 30". I wondered with all the improvements in motor oils since 1975 if there would be a benefit to using a particular type in that BIG engine. Also, oil filters sold to fit this vehicle seem to be very small in size and overall filter area. Would not that effect ability to filter adequately? Thank you in advance for your replies. Ttommy.
Recommended oil for 1975 Cadillac Eldorado 500 CID
- Thread starter ttommy
- Start date
- Status
Use 5W-30 or 0W-30. Don't use straight 30.
This is a very large displacement engine that makes no real power.
It can't be all that demanding of its oil.
I'd say any 10W-30 or 10W-40 would work well.
Original rec would have probably been 10W-30 since GM recommended specifically against the use of 10W-40 grades when this car was new.
I got to repo a couple of '78 Els back in the day when they were still almost new.
A big, floaty car of what would today be considered garish appearance.
Still, your '75 would be a neat period piece to have and enjoy.
This sounds like a really neat car.
How about some pics?
It can't be all that demanding of its oil.
I'd say any 10W-30 or 10W-40 would work well.
Original rec would have probably been 10W-30 since GM recommended specifically against the use of 10W-40 grades when this car was new.
I got to repo a couple of '78 Els back in the day when they were still almost new.
A big, floaty car of what would today be considered garish appearance.
Still, your '75 would be a neat period piece to have and enjoy.
This sounds like a really neat car.
How about some pics?
Without a UOA to determine what the fuel dilution percentage is I do not recommend using a 5/0W30.
I would just use a 10W30 of your choosing and unless you want to run 15K OCI's I would not worry about the thimble oil filter.
I would just use a 10W30 of your choosing and unless you want to run 15K OCI's I would not worry about the thimble oil filter.
I realize I'm totally wasting my time here, but from my previous experience with the Cadillac (425, 472, 500 CID) engine family, I'd whole heartedly recommend Mobil Super 20W-50 for quietness and smoothness.
Originally Posted By: Merkava_4
I realize I'm totally wasting my time here, but from my previous experience with the Cadillac (425, 472, 500 CID) engine family, I'd whole heartedly recommend Mobil Super 20W-50 for quietness and smoothness.
Why? You do not like varnish. Using a PCMO with a 30 grade spread is a good recipe for varnish.
I realize I'm totally wasting my time here, but from my previous experience with the Cadillac (425, 472, 500 CID) engine family, I'd whole heartedly recommend Mobil Super 20W-50 for quietness and smoothness.
Why? You do not like varnish. Using a PCMO with a 30 grade spread is a good recipe for varnish.
Maybe he can get some leaded gas and tire tubes at the same time.
5w30 or 10w30 of your favorite flavor.
Either will do a better job than the oils it speced in the day
Either will do a better job than the oils it speced in the day
I would use defy 5w30 or Maxlife 5w30. Mobil 1 5w30 high mileage if you want synthetic.
Originally Posted By: fdcg27
This is a very large displacement engine that makes no real power.
It can't be all that demanding of its oil.
Low rated horsepower (210hp?) but 380 ft/lbs torque. Torque is what you feel in the seat of your pants.
Love those old cars, had a 78 Eldo, required lots of torque down low to move them.
Old guy once told me, "horsepower is how fast you hit a wall, torque is how far you go though the wall."
This is a very large displacement engine that makes no real power.
It can't be all that demanding of its oil.
Low rated horsepower (210hp?) but 380 ft/lbs torque. Torque is what you feel in the seat of your pants.
Love those old cars, had a 78 Eldo, required lots of torque down low to move them.
Old guy once told me, "horsepower is how fast you hit a wall, torque is how far you go though the wall."
Last edited:
Originally Posted By: Lex94
exactly...use a 10w30...5w30 oil is now obsolete.
Nobody said 5w30 is obsolete, however 10w30 generally has a higher hths than 5w30. The engine will die from age and general wear before cold starts will ever be a problem... If they even are for modern cars.
exactly...use a 10w30...5w30 oil is now obsolete.
Nobody said 5w30 is obsolete, however 10w30 generally has a higher hths than 5w30. The engine will die from age and general wear before cold starts will ever be a problem... If they even are for modern cars.
Thanks to all for the quick replies! I've had this car 4 years and I am the 4th owner. Prior owner rode it in parades but I use for cruising 9 Mos. It's due for an oil change so I will give one of those recommendations a try. This car gets better gas mileage than my '97 F-150. Here is a pic of a clone car from the internet as my own pics aren't linked to any URL as required to download to these posts.
http://www.2040cars.com/_content/cars/images/99/399999/001.jpg
ttommy
'97 F-150 121k
2000 Infiniti I -30 255k
2002 Lexus 209K
1975 Eldorado 50k
1981 Honda CB 750 5k
1974 Yamaha TX 500A 9k
http://www.2040cars.com/_content/cars/images/99/399999/001.jpg
ttommy
'97 F-150 121k
2000 Infiniti I -30 255k
2002 Lexus 209K
1975 Eldorado 50k
1981 Honda CB 750 5k
1974 Yamaha TX 500A 9k
Originally Posted By: Lex94
I said 5w30 is obsolete.
The lower spread of 10w30 means fewer VIIs that can lead to varnish and sludge. The new GF-5 10w30 oils are so close to 5w30 now but without all that VII polymer.
I would recommend Pennzoil 10w30...Smooth as butta.
are you posting from 1975?
I said 5w30 is obsolete.
The lower spread of 10w30 means fewer VIIs that can lead to varnish and sludge. The new GF-5 10w30 oils are so close to 5w30 now but without all that VII polymer.
I would recommend Pennzoil 10w30...Smooth as butta.
are you posting from 1975?
Originally Posted By: Lex94
Sooo...Are 5w30 oils shear stable in 2014?
Who cares........it's the wrong oil for a 1975 Cadillac 500 anyway.
Sooo...Are 5w30 oils shear stable in 2014?
Who cares........it's the wrong oil for a 1975 Cadillac 500 anyway.
- Status
Similar threads
