Engine Oil

[carmover]

What is the best oil to run in my 25 Buick Standard. I have been using Quaker State Defy but I remember a previous post about using Shell Rotella but I have been unable to find the post and Defy is getting harder to find.

[Hubert_25-25]

I put Shell Rotella in the 1922 Dodge after reading a lot on the forums, and I plan to use Shell Rotella in my 1925 Buick.  Hugh

[carmover]

Thanks Hugh,I am going to give Rotella a try.I have used it for years in my larger diesel engines in my big trucks with good results.

[26-25Buick]

It seems to be driven more by personal choice and availability these days but I've always used Penerite Shelsley Heavy in the 1926 but I've often wondered if Shelsley Medium would be better in our warmer climate.

[C Carl]

What viscosity are you guys using in your '20s cars ?  - Carl

[Mark Shaw]

20W40

[Brian_Heil]

20w50    (and I don't drive/start it in the cold weather/season here).

 

Have not been able to forgive Shell for their Fire n' Ice debacle of the early 1980s.  I'm sure Rotella is fine, lots of diesel truck fleets use it, but I still shop with a grudge.

 

I get Wolf's Head at a discount, use it in everything in the required viscosities and have for 20+ years.

[Terry Wiegand]

I'm with Brian on the 20w50.  I have run Havoline 20w50 in everything I've ever owned since I was a kid.  My Dad never used anything but that.  When I have the engine rebuilt in the '16 and it goes back together with modern rings and tighter cylinder wall clearances, I am thinking that I will run 10w40 in it then.  Engine tolerances were a whole lot looser almost 100 years ago and in my humble opinion rings that were almost a half inch wide was why these old engines tended to smoke.  Again, just my opinions here.

 

Terry Wiegand

Out in Rainy Doo Dah

[C Carl]

Yes , that is what I figured too. I have been running 15W/50 , or 20W/50 synthetic in the ancient machinery. Recently switched to the fairly new 20W/50 Amsoil with zinc and phosphorus levels apropriate for old engines. I used to run the heavier synthetic in my modern engines also. However , after talking to the Mobil 1 rep. , and reading Richard Widman's paper , I have gone back to the owners manual specs for the more modern engines. I don't second guess my doctors or my lawyers either. Smooooth sailin' !    - Carl

[Larry Schramm]

IMO, the cheapest oil today is better than the best oil when the cars were built especially the prewar vehicles.

 

That said, I use Shell Rotella in my old trucks.

[Hubert_25-25]

I am a big proponent of modern synthetics, and I like to use them where I can, but with no oil filter, I don't think they are worth the added cost for these prewar cars.     Hugh

[26-25Buick]

The Shelsey Heavy is 40-70W and the Shelsey Medium 25-70W both with a good loading of zinc

[27donb]

20w-50

 

For the amount of mileage I put on the Buick(s), synthetic doesn't make sense economically.  Synthetic is made to go and last for so many more miles than conventional, if I changed it as often as I do conventional it would be a waste of money, and if I left it in for the recommended miles it would never get changed.

[Dynaflash8]

My '39 Buick Series 40 engines have been gone through, one rebuilt, one overhauled.  I want to say that first.  Quite by accident, I did an oil change with Shell Formula One 20-50 motor oil.  Suddenly I noticed that my oil pressure had improved by at least 5 pounds and maybe a little more in the overhauled car.  The more oil pressure the better in these old straight 8 engines.  One car was totally rebuilt with insert bearings.  The other car was just overhauled...you know, new rings, valve job, maybe the rod bearings were "adjusted"....it was 1970, so I don't exactly remember.  Of course, I also installed 1941-53 oil pumps in both cars, which have 25% larger gears and give better oil pressure.  That's very important, okay?

 

What these cars were famous for was as they wore, the oil pressure would have a tendency to go down to some low point the further you drove them and the hotter the oil got.  Some would get so they barely showed anything when idling.  When they get that way, they are on borrowed time.  I threw a rod in one of my cars back in the 1960s by ignoring the fact.  My Dad's car did it after he had it overhauled in the late 1940s.  He complained and the dealer told him if it ever blew up they would fix it for free.  Dad was careful I guess, and he never threw a rod, so I didn't realize the importance.  Years later I talked to the kid that owned it next, and yes he threw a rod through the side of the block.  I think more about oil pressure on these old straight 8's now as the top priority, and if I want to buy one I want to drive it long enough to see how low the oil pressure goes, because they always have good oil pressure when you start one up cold that you are looking at.  And, it takes about 15 miles at road speed to really see how good or bad it is.

 

I speak from a lifetime of experience with 1939 Buick Specials, and I'm 78 years old.  Dad got his when I was 3 and I got my first one when I was 16.

 

Okay, to Shell Formula One 20-50 oil.  The blue car with the rebuilt engine with insert bearings has always carried 45 lbs at 50-something miles per hour and still does.  The idle went from 15 lbs to about 18 lbs.  However the other car with the overhauled engine would run about 30 lbs at 50-something and idle at maybe 10 lbs.  That's adequate, but it could be better.  With Shell Formula One 20-50 it suddenly jumped to 35 lbs and idled at about 15 lbs hot.  On a long trip (85 miles one way) it did eventually work itself down to about 32-33 pounds and when I got there it idled about 12-13.  It's hard to tell but it was the same needle width over 30, not under 30 as before.

 

Maybe these results seem small, but believe me, with these cars require every little bit of increased oil pressure you can get.  It isn't just important, it is very important.  The only place you can buy this oil is at Shell stations, and some have to order it.

 

 

 

 

[Larry Schramm]

It is funny that this thread talks about oil pressure and time to change the oil.

 

On one of the earlier Buicks that I owned in the 60's or 70's I would watch the oil pressure and it seemed to take a sharp drop at about 3,000 miles just like clock work.  As soon as I changed the oil, the pressure would pop back up to "normal" range.  Then the cycle would repeat it's self.