What is the correct recommended motor oil weight for the 1949 Olds 88? I know I’ll need an oil with ZDDP, just unsure of the weight.
thanks!

 

10w30 should work fine.

 

What is the expected temp range when it will be used? Rebuilt or tired engine?

 

Mulii-viscosity oils were not released until 1954.

t would have likely used straight 30 weight unless operated in very cold climates.

Look into Joe Gibbs oils that have high zinc content.

 

Do you have any idea what's in there now? I bet after 72 years it's not straight 30 weight.

 

Multi-viscosity oils may have been developed later than his car but I can see no reason multi vis oil with the proper amount of zinc should not be used. Many cars of that vintage were subjected to 30 wt non detergent oils and had the sludge to prove it. Oils have gotten better even for older old cars...... Tedd

 

As mentioned, it would be best to know the ambient temperatures and the degree of wear in the engine before making a choice. Some multi-viscosity with sufficient zinc would likely be best.

 

The engine has 29,000 original miles. No joke. I live in Maine. While it wouldn’t see the road in the winter, it would still need to start. Sounds like 10-30 with zddp is the eighth choice.

 

Why would it need to start in the winter if your not driving it?

 

I run Valvoline VR1 20W50 in my 54 Olds. It has all the zinc you need. I tried 10W30 but it seemed the car drank more of it. With the low miles and living in a cold climate (I live in Texas) you might want to start out with 10W30. You don't need ZDDP with this oil.

 

As mentioned, a 10w-30 with sufficient ZDDP would work. I'd look for an oil with the ZDDP already chemically engineered into the formula. Have read that around 1200 ppm of ZDDP is sufficient.

 

Thanks everyone! To answer a question, the car will need to be started in the winter to move it in and out of a shared work space. I run a commercial garage from home. Can’t have my car take up a bay during work.

 

Not warming the engine, transmission, and exhaust system completely with enough time to burn off moisture is the worst thing for your car.

 

Go to Walmart and get Shell Rotella 10w-30HD. You need HD because of hydraulic lifters. Rotella protects better than regular oil. Don't need synthetic.

 

I'm sorry but your wrong, Rotella is not better than a conventional oil with the correct friction package designed for flat tappet engines. Rotella is designed for the newer diesels that have emission systems.

 

it’s bad no doubt, but getting welding slag, and cut off wheels zipped at it while in working in the next bay just ain’t an option!

 

Look at the API rating. All the Rotella I've ever seen had both S (spark) and C (compression) ignition ratings. Promise it's better stuff than the SA and ND oils in use when that engine was new.

Yes, all oil formulae have changed since flat-tappet engines went out of style.

If the engine is quiet, doesn't smoke or use excessive oil, any API SG or later 10w30 or straight 30 oil should be fine. Olds factory installed a lot of 20 weight oil thru about 1966. Little known fact: factory installed oil in Olds and Cadillac was supplied by Kendall (now Brad Penn) for decades. Brad Penn would work great in your 303.

Just stay away from synthetics. 50s engine design and metallurgy not compatible with it.

 

When you move the car in and out, let it run till thermostat opens and coolant and fluids are circulating and up to temperature.

 

I've been using Rotella in a 1964 350 bored engine for over 15 yrs., and in a 51 Olds V8 bored and cammed for same time. First read about it in an old Rod magazine. It was made for Diesels but when regular oils started having all the helpful additives removed it was recommended as the way to go. Hasn't hurt either engine during that time. Also run it in a 68 442, and ran it in a 432 Steel-crank Big Block Olds w/no probs. It works for me!

 

I haven't verified it but I have heard on this site that Rotella not longer has all the zinc in it that it used to have. Valvoline VR1 Racing Oil still does. I have been running it in my 54 Olds for several years. I am not trying to argue the attributes of one oil over another. I am just saying what works for me. My car likes the 20W50 lots better than the 10W30. On the other had maybe it likes the 10W30 better because it drinks it like crazy. Do you own due diligence and do what you think is best for your car.

 

I checked specs on Rottella T4 15 40 a few weeks ago and the zinc was 1100 ppm

 

I use the Rotella 15-40 in my 55 and a lot of farm equipment also but my main reason I switched was because it fixed my lifter sticking issues. A added bonus is it doesn't seep through the cork gaskets like synthicks do on these older engines.

Different oils are like the difference between blonds and redheads everyone has their favorites...... Tedd

 

I am not a chemical engineer, but from everything I've read, I suspect any modern, reasonable range multi-viscosity oil would certainly be better for your car than OEM supplied oil when your car was built. The possible exception being the Zinc content. I am currently running Mobil 1 full synthetic 15W 50 in my 1967 442 400ci. This full synthetic oil has 1300 ppm Zinc and the specs also state it is formulated to be good for flat tappet applications. What's also appealing, unlike some other Mobil 1 products, is that it's relatively cheap. You can pick up a 5 Quart jug at Walmart for $25. My car loves the stuff. The specs for this oil are at the bottom of page 3 of the attached Mobil 1 spec guide.