Re: Engine oil

Posted by Tim Cole On 2008/2/6 18:40:41

Oh Boy! The Packard Manual specifically recommends against detergent motor oil use prior to 1955. Valvoline non-detergent 30W is a good choice as is Kendall ND 30W. You want oils rated SB. Pitt-Penn makes a 10w-30 non-detergent oil which is better than straight 30w.

I have contacted oil companies about this oil issue and they don't recommend diesel oils and 20w-50 is not an authorized grade. They recommend you follow the owner's manual service intervals and guidelines.

However, If you want to use detergent oil petroleum engineers recommend the oil change interval be reduced by half. For Packard that is a 1000 mile interval for detergent oil changes.

The rule of thumb is that if your engine does not have a full flow filter then use non-detergent SB rated oil formulated for automobile engines.

I have been seeing a lot of premature engine wear from extended oil change intervals in old cars. For Packard that is a very expensive proposition.

If you are driving your car at sustained highway speeds then perhaps heavier grades may help, but if you are driving at low speeds heavy oils are detrimental.

I wouldn't cruise any pre-1955 Packard over 55 and prefer 45-50. Especially after having seen what happens in a high speed collision.

In the old days the 55 mph speed limit helped, but modern cars are just too fast and I would stick to the secondary roads that the cars were built for.

HAPPY MOTORING!