We hope to expand this section over time. However, it is up to you. If you have a question about your car, restoration, the Club, or whatever, we will try to get an answer for you and publish it here. Your name will not be published unless you give us permission.

Since writing Packardtips 101 (see article under What Kind of Oil to Use on the opening page of this website) on the advantages of using Diesel rated oil with an SL rating amongst its other benefits, I have received numerous emails and phone calls from members with questions regarding this topic. Also, I note that other car clubs and organizations are publishing information on this topic as it is becoming an important issue. Here are some of the questions and answers:  

I have been using a straight 30 oil. Can I change to a multigrade?  

Yes, if fact you should do this. There seems to be a story that you can’t use multi grade oil in old cars. Where this came from I have no idea, but the myth persists. Multigrade oil was developed to assist with lubrication when starting as it stays thin when cold. That helps any type of engine.  

Can I change to a detergent type of oil if I have been using a non detergent oil?  

Yes, it won’t harm anything. Detergent oil keeps an engine clean as it holds dirt particles in suspension rather that let them settle to the bottom of the pan. These dirt particles are then picked up by the filter. If your car doesn’t have a filter then they would continue to circulate, which is what they would be doing with the single grade oil, in any event. Detergent oil is not strong enough to dislodge hunks of sediment and “plug up the lines” as I have heard people say over the years. It may, over time, dissolve some of the sediment, but it is very gradual.  

Should I clean out the oil pan from time to time?  

It is always a good idea to have a look at least once if you have just bought a car or have owned your car for many years to see what is there. On most older Packards the oil pan is reasonably easy to remove. From 1951 on they get a little tougher but are still reasonably accessible. The worst cars are the “original low mileage” cars. If a car is over 50 years old and has only 50,000 miles on it – great – but not so great for the oil pan. It has got to have some sludge in it if it has never been removed. Also, the oil pick up screen should be cleaned as that is where most of the problems will be.  

Is all Diesel oil rated the same?  

The answer used to be yes – but not anymore. There is a general trend towards requirements for lower sulfur emissions from diesel engines. This has led to lower levels of sulfur in diesel fuel. They have also eliminated sulfur from oil and are reducing other “harmful” compounds as well. To make it more complicated, many of the new diesel engines do not have a camshaft. Instead, they use solenoids to push the valves open at the appropriate time. This is controlled with the computer. The result is that we now have variable valve timing so that the engine is always running at peak efficiency. This is great for the trucks, and the environment, but the result is that some of the new diesel oils are not SL rated because there is no camshaft to lubricate. Therefore, always read the label to make sure that the oil is SL rated. And – don’t assume that just because a particular oil is SL rated this time you buy it that is will be next time. Check the label every time you buy oil. The ratings are changing on a regular basis. Remember the brand of oil doesn’t matter. It is the SL rating that matters.  

Some oil is SL and SM rated. Is that OK?  

Yes it is. As long as the SL rating is there you are covered.  

What about synthetic oils?  

Synthetic oils are great but have little to add to a vintage car. They are primarily designed for high speed, high stress engines, often equipped with turbochargers and under those circumstances will provide better lubrication – at least that is the claim. In an old low speed low stress engine like a Packard, the higher cost cannot be justified. They are rated differently so you will not see the SL rating, but I am led to believe they will lubricate the cam and lifters as needed because of their ability to take high stress. So, the answer is; you can use them if you like, but I do not believe anything will be gained over a lower cost SL rated oil.