Pick my oil '75 Plymouth Gran Fury 400 big block

[gallydif]

Well not my oil. I wish. My friend just got a 1975 Gran Fury with the 400 6.6L v8. 92k original miles. Didn't see any oil leaks. To early to tell if he will need to keep topping off or not. Wants to know which oil and what viscosity to use. Unfortunately, I'm not too familier with the old Chrysler engines. I was thinking some 10w-40 dino like Chevron and right now they're running the $5 rebate too. Or even go 20w-50. I know bitog'ers generally don't like that thick stuff.

He also wants to make it his daily driver. What's the general reliability of these? How's the tranny? Time to Chime in my mopar peoples.

Location: the Florida Keys. Very hot and humid year around. Salt in the air. Told him to keep it well waxed to keep rust away.

 

[eljefino]

Rotella 15w40

 

[Elevguy]

Watch the valve guide oil seals, good engine worked on a lot of them back in the day

 

[skyactiv]

Humidity mean nothing. I lived in Clearwater eons ago. Miami gets hot, but not as hot as it can in the midwest. I'd run a good 10W30. Shell Rotella T5 at Wal-Mart There is no need for a XW40.
http://www.walmart.com/ip/20573564?wmlsp...032&veh=sem

 

[Inspecktor]

Those old Mopars tend to cook the valve cover gaskets because of the exhaust manifold location. You may mot see leaks, but would smell burning oil as it cooks off. They are happy on any oil, and should give many miles of service.

 

[Kuato]

Originally Posted By: eljefino
Rotella 15w40


Sounds like a great choice....

 

[gallydif]

Originally Posted By: Kuato
Originally Posted By: eljefino
Rotella 15w40


Sounds like a great choice....

Isn't Rotella for diesel engines?

 

[meborder]

It's dual rated and acceptable for use in both gas and diesel engines.

I'd probably use rotella T5 10w30 unless I started to see low oil pressure at hot idle, then id probably use 15w40 until I could get it rebuilt.

 

[901Memphis]

Mobil 1 High Mileage 10W30

 

[SZR48207]

Originally Posted By: gallydif
Originally Posted By: Kuato
Originally Posted By: eljefino
Rotella 15w40


Sounds like a great choice....

Isn't Rotella for diesel engines?


Not only diesels, but a lot of motorcycle owners use it, especially in air cooled motors. It's very robust, handles well against fuel dilution, and is very economical.

If Rotella can survive in my VTwin that I regularly take up to 9k rpm then it'll do well in your classic car.

 

[Doog]

Rotella 15w40 or Brad penn 10w40

 

[Reg# 43897]

I'd 2nd the vote for T5 10w-30...

John.

 

[Merkava_4]

20W-50

 

[BrocLuno]

Originally Posted By: meborder
It's dual rated and acceptable for use in both gas and diesel engines.

I'd probably use rotella T5 10w30 unless I started to see low oil pressure at hot idle, then id probably use 15w40 until I could get it rebuilt.


Yup, the HDEO's have been the go-to oils for many older V8's for years. They are generally tough oils with a strong add-pak. T5 would be a great choice for that engine

 

[FCD]

Originally Posted By: gallydif
Well not my oil. I wish. My friend just got a 1975 Gran Fury with the 400 6.6L v8. 92k original miles. Didn't see any oil leaks. To early to tell if he will need to keep topping off or not. Wants to know which oil and what viscosity to use. Unfortunately, I'm not too familier with the old Chrysler engines. I was thinking some 10w-40 dino like Chevron and right now they're running the $5 rebate too. Or even go 20w-50. I know bitog'ers generally don't like that thick stuff.

He also wants to make it his daily driver. What's the general reliability of these? How's the tranny? Time to Chime in my mopar peoples.

Location: the Florida Keys. Very hot and humid year around. Salt in the air. Told him to keep it well waxed to keep rust away.

20w50 works well in many engines but for yours it might be a lil too thick, Rotella 15w40/10w30/5w40 is all your engine needs, it's the go to oil for most old school american V8's, Mobil 1 15w50 is a thin 50 weight that has been proven over the years to be an excellent oil and is available throughout the US so consider that too

 

[Red91]

Delo 400 SAE 30.
1220 Zinc
1100 Phosphorus
-17 degee F pour point for all those "cold" starts.

 

[Gene K]

10W30 HDEO
Rotella, Delo, Delvac whichever you prefer.

 

[fdcg27]

This car is pretty much old-school Mopar so it should be well made. This is a big, lazy engine that shouldn't stress the oil unduly, although shortish drain intervals might be in order just due to potential fuel dilution with a carburetor. The tranny will be a three speed Torqueflite that should be serviced but is quite durable and reliable.
Reliability should be on a par with any other well-made forty year old car that's seen light use over its life.
I'd expect niggles with the brake hydraulics, the cooling system and the electrics. Once these are sorted, this car should make a reliable if thirsty daily driver.
I'd start with a 10W-30 grade oil and go from there if needed. You could use a 20W-50 in the FL Keys but that probably isn't needed, although that grade was once a popular choice among those who thought that they knew better than any company that built hundreds of thousands of engines each year.