What's good for my cars?

[JREwing]

I have a 2000 DTS with the Northstar (80k), a 2005 CTS with the 3.6 (25k), a '76 Fleetwood with the 500 cid (32k) and a '79 Deville with the 425 cid (46k).

I'd like to go with true (Class IV and up) synthetics for these cars, both for the cleaning properties and the lengthened OCIs.

The CTS, DTS and '79 are driven regularly, while the '76 is a garage queen. The CTS has been on Mobil 1 since new, but recent controversies have me looking for something else. The other three cars have been on dino since new.

I've only recently started changing my own oil, and figure I might as well use the best if I'm going to take the time to do the work. Thanks in advance for the help.

 

[mitchcoyote]

You are a perfect candidate for Amsoil. They ship it right to your front door.

 

[Merkava_4]

Quote:

---

and a '79 Deville with the 425 cid (46k)

---

I've got some parts for your Deville:

1. Air cleaner assembly.
2. Engine compartment braces - complete.
3. Left and right side remote mirrors - both with cables.

 

[JREwing]

I'm impressed with the Amsoil talk I've read here and elsewhere. Any suggestions on viscocities recommended for my apps?

 

[JREwing]

Quote:

---

Quote:

---

and a '79 Deville with the 425 cid (46k)

---

I've got some parts for your Deville:

---

Thanks, but she's in pretty good shape at this point.

 

[Merkava_4]

Quote:

---

Any suggestions on viscocities recommended for my apps?

---

5W-30 for the newer Cads and 10W-40 for the '76 and '79.

 

[Herman]

It is my understanding that amsoil is a great product but that in situations of storage a mineral oil will provide better cling to metal surfaces. I may be wrong but in those older cars a straight vis. mineral oil may provide better protection than a multi grade filled with VI Improver. But again thats just what I have read. I am no chemist. I have a green 72 cadi eldorado with a white top. with the 500 ci engine.

 

[Quest]

Actually, I personally prefer regular motor oil than syn on cars under frequent storage due to that fact that dino oil tends to be more hydroscopic (water-affinity) and that helps in keeping the moisture under crankcase under control). Also: it's more economical to drain dino oil to rid of moisture than costly botique syn oil.

If you are afraid of corrosion on cylinder bores and such for cars over extended period of storage time, you shall seriously consider using fogging oil (winter storage) to fog the entire intake and exhaust ports, cylinder walls (through spark plug holes), etc. and then crank it over a few times.

Failure to observe proper storage precautions will cost you an engine rebuild esp. in high humidity areas.

 

[teven7492]

JREwing... if you use a PAO synthetic in the 76 and 79 those engine WILL develop LEAKS. The gasket and seal material were not designed for synthetic. HERMAN you are correct mineral oils will leave a better film on metal parts after hot shut down than a full synthetic. VALVOLINE MAXLIFE 10w30 would be great choice for the 76 and 79.

 

[dave1251]

Quote:

---

JREwing... if you use a PAO synthetic in the 76 and 79 those engine WILL develop LEAKS. The gasket and seal material were not designed for synthetic. HERMAN you are correct mineral oils will leave a better film on metal parts after hot shut down than a full synthetic. VALVOLINE MAXLIFE 10w30 would be great choice for the 76 and 79.

---

That is an bold statement. Saying that something WILL leak. Maybe it will. But when was the first synthetic PAO oil used. Ask one of the Amsoil reps here. I think it was around 1972. Not every car that used an PAO basestcok oil developed leaks back then.

 

[teven7492]

dave1251.. for your information, Amsoil used a diester basestock not a PAO. Mobil's first synthetic used PAO and one of the biggest problems they had were leaks.

 

[dave1251]

Quote:

---

dave1251.. for your information, Amsoil used a diester basestock not a PAO. Mobil's first synthetic used PAO and one of the biggest problems they had were leaks.

---

You know your motor oil history. But with that said. Saying something that using an PAO based oil will cause leaks is still an BOLD statement. Will using an PAO based oil maybe. But you will not know for sure until he tries. There are several things done to add pliability to PAO based oils. Such as adding a bit of ester to swell the seals.

 

[JREwing]

Leaks ... certainly not cool. I suppose I could try, and always go back to something like the MaxLife if need be. I'll give it some serious thought.

I'm also interested in Auto RXing the older cars, as well as the '00. Should I be careful with that on the older cars?