Author Topic: Correct Engine oil  (Read 406 times)

Offline Building 3

  • Sr. Member
  • ****
  • Posts: 315
Re: Correct Engine oil
« Reply #15 on: December 07, 2017, 07:02:50 PM »
The owner's manual for 1966 said to use 10w-30, but if it's cold a 5w could be used, if hot then 40, so I think you can use anything in that range 5w to 10w, and 30 or 40.
1966 289 C code auto convertible December 1965 scheduled build at Dearborn.

1966 289 C code auto convertible
October 1965 scheduled build at Metuchen.

Offline 69cobrajetrugae2

  • Sr. Member
  • ****
  • Posts: 289
Re: Correct Engine oil
« Reply #16 on: December 09, 2017, 11:46:38 AM »
Our 66 convertible with 15K miles will be for sale soon for 55K and when the video is available I'll post it here. There are many so called survivors with 10 15 20K miles but they don't have date correct Carlite glass that ours has and the windshield is mint/near mint which is one proof of 15K miles and there are many others which I'll outline in the video.

 I made a mistake using 15/40 in this car since we don't drive it much and it's likely that the VI improvers degrade once the oil gets hot and it thickens just sitting in the crankcase regardless of the mileage.  VI improvers begin to lose their chain mechanism after 1000 miles according to reliable sources.  On a cold start I heard noises that concerned me.  I switched it to a 5/20 conventional and the noises have not returned.  Oil temperature will not exceed 120F to 140F if the ambient temperature is 40F or slightly below.  If the radiator is partially blocked with tin to the extent that the thermostat does not close once it warms up will help to heat the oil but the oil pan is in the cold airstream so insulating the pan would help as well.  Installing an oil temperature gauge will provide the information that is necessary to select the proper grade of oil for winter and summer driving.