Any major brand, 10W30.

Any worry about the elimination of zinc and sulfur in the new oils? It's my understanding that severe and excessive wear can occur without these in older engines.

The concern over insufficient zinc, etc., is really for more high tech engines than our Hudsons. We have low valve spring pressures, etc., that don't really require the exotic lubricants. Maybe with a full-up racing performance Hornet, but not us everyday guys cruising to a meet or car show.

It's probably true that only the engines subjected to extreme wear, will need the zinc additive, but I'm not sure that the facts are all in on this issue. I use a type of oil that doesn't cost a whole lot more than regular oil, but has large quantities of zinc in it. Just to be sure.

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I use Castrol 10-40 with a container of STP, heat it in a pail of hot water and it pours right out. I drive my car cross country, ocean to ocean, 500 miles per day at high speed and cover 3,100 miles in 6 days. My engine has 143,000 miles since rebuilt in 1998. Still runs like a top, and no zinc. Using 50 weight will wear out the oil pump gear. Walt.

Great information! Thanks so much for all your input!

I agree with what Park said. The stink over zinc (or ZDDP) is directed at flat-tappet-cam engines produced in the era between the advent of high valve spring pressures (think "Horsepower Wars" days) and the common use of roller cams, hence the warning that one should be wary of it in pre 70 or 80 something engines, assuming that every engine after that had a roller cam. It's the high force, sliding motion between cam-lobe and follower that gets 'em. Diesel rated motor oils (usually a 15-40 in the multi-grade oils)aren't subject to the Gov't mandate regarding reduction of ZDDP levels so many choose to use those. I've never heard of ZDDP reduction as having any effect on other components. Conventional rocker tips could be another victim but we don't have those, do we? (Sorry, Hash/Packard guys)
I guess this means those pre-'34, roller-tappet Hudsons are safe.
F

I did a big study on oil back when I built my 308 Twin H for a run on the Bonneville Salt Flats. I could give you a Loooong page of data and study information (the engineer in me) but, bottom line is a good grade of 10-30 is what you should use. I have never been a fan of oil additives (Walt could not be wrong) no matter what the name on the can. They mostly add a wax base to the metal parts that might help with start up after a long idle period, but I am not convinced that this is needed with our cars. Be sure to change your oil every 3000 miles like clock work-with or without an oil filter (by the way, the oil filters only filter about 30 percent of the oil so they serve little or no value.

My oil filter kit filters all the oil that gets by the by-pass check valve. It's a modern oil filter used on new cars. It keeps the oil clean for over 3,000 miles. The old filters that came on the engines only has a 30 thousand return hole in the center pipe. Hudson manual says oil pressure with a hot engine should be 38 pounds at 35 MPH, and 20 pounds at idle. Any more just ruins the oil pump gear. 10-40 is the best oil to use. I'm going by my engine that has 143,000 miles since 1998 and has never been touched. This with all high speed driving along with 12 trips cross country. To each his own. Walt.

Thanks again for all the input. Although I'm new to the Hudson world, I've been restoring,rebuilding and collecting autos and motorcycles for most my life. I've run Kendall in my vintage Triumphs for years and have had no oil related problems. I believe that's what I will use in the Super Six. Best Regards. Mike..