Topic: Correct Engine oil

[6T5 Fastback]

I just picked up a 65 Fastback and the previous owner said he rebuilt the engine a few years ago to the 289 HiPo specs. He sent me a picture of the oil he had been running and its Joe Gibbs HR-1 15W-50. Some people have said that its not necessary unless you plan on racing, and have suggested 10w -30 0r 10w-40 is totally fine. Stay away from synthetic ? I basically only have her out on sunny days and garage kept.  Any help would be great Thanks

[carlite65]

i would choose a quality 10W-40 oil. have you checked the actual oil psi with a mechanical gauge??

[jwc66k]

I use 20W-50 in my older cars, and have since I bought my first Ford in 1963 (a 1960 Starliner, 292 2v). I change the oil and filter every 3000 miles. Any lower weight oil may cause problems, engines then were not built to todays tighter tolerances. Using a synthetic oil is a waste of money.
Jim

[6T5 Fastback]

I have yet to check the actual oil psi but will do . thanks for the suggestion

[Brian Conway]

The Gibbs oil is an excellent product and running the 15-50 should tell you the builder/owner expected some degree of performance.  Your demands on the engine and local weather conditions should help you decide what would be the best choice ?  Probably stay with the Gibbs ?  I get a little ' spirited ' occasionally, live in San Diego, and I run straight 30 wt. VR1 in my stock 65.  The filter, Motorcraft FL-1HP, and oil are changed, at least, every 3000 miles or two years.  Brian

[dave6768]

Don't scrimp on the oil...it's the life blood of the engine.   Joe Gibbs, Brad Penn, VR1, etc. all have sufficient levels of ZDDP, zinc dialkyl dithiophosphate.   The newer oils don't have enough of this to protect our flat tappet cams.  If you have a roller cam, not an issue.  You can also buy products like Cam-Shield and add it to your oil.   I add a bottle of red STP to each oil change with conventional 10-30 Pennzoil.

[CharlesTurner]

I've been using Rotella T 10W30 on all the old flat tappet engines, also has additional ZDDP.

[sgl66]

Lots science behind it but the bottom line is getting the right mix of ZDDP for flat tappet solid lifters found in Hipo motors. I’ve been using Mobil 1 15-50 for over 25 years with no issues. Here is the best comparison chart I’ve seen https://mobiloil.com/~/media/amer/us/pvl/files/pdfs/mobil-1-oil-product-specs-guide.pdf

[Building 3]

That Mobil 1 attachment is a good chart. The 15w-50 says right there it is for flat tappets. When our classic Mustangs were being engineered and built the API specification for zinc and phosphorous was 1,000 to 1,200 ppm for API SC to SE. The SF rating in 1980 raised it to 1,400. The present ppm is in the 600 to 800 range to protect catalysts to 150,000 miles. However there are exceptions. The euro spec oils for MB, VW and Porsche still have 1,000+ ppm as do the diesel oils and the Mobil 115w-50. We have all heard and read too many horror stories about flat tappets to risk any oil less than 1,000 ppm. Why take a chance when there are really good modern oils out there with 1000+ ppm? I decided that I would only use API certified oils from manufacturers that actually have the expertise to provide lubricants to the manufacturers, Ford, GM, FCA, the Euros, etc. For newly rebuilt engines I have used synthetics and have not had a leaking problem. Mobil 1 15w-50, 5w-40 for instance. For original engines I have stuck with conventional oils, not wanting to risk leaks. Maybe it will leak, maybe it won't, but why go through the hassle?  So my choice there has been Shell Rotella T-4 10w-30. It is also available as 15w-40. Both have 1100 ppm. Also, I have not used it, but Castrol Edge Synthetic in the 5w-50 weight only, says specially it is for classic and older vehicles.  It has 1250 ppm of zinc & phosphorous.

[jwc66k]

I've used Quaker State and Pennzoil almost exclusively following my father's preference. This comes from the very early 1950's when I "helped" him change oil on the family car, a 1950 Plymouth. To give credibility to his choices, he was an Aviation Machinist Mate/Aviation Pilot Chief. The only thing different is I use a ZDDP additive.
Jim

[dave6768]

I've been using Rotella T 10W30 on all the old flat tappet engines, also has additional ZDDP.

Unfortunately, it does not have as much of the good stuff as it did years ago.

[6T5 Fastback]

Has anybody used or have feedback on Lucas Oil products ? They have a Hot Rod Classic line .
Thanks to everybody for sharing their advise and knowledge

 https://lucasoil.com/hotrods-classic-cars

[Bartman]

I use Lucas hotrod 20w50 in my 65 k code hipo. I’ve been very happy with it.   It’s apparently designed for classic motors with mechanical lifters.

[6T5 Fastback]

Is there any chance of harm using 10W40 or 30 vs 20W50.
Thanks
 

[Hipo giddyup]

 Wouldn't recommend 20w50 in cold weather. Some folks change their 20w50 to 10w40 when the weather gets cold (northern states). I would think it would be hard on your internals at start-up when the thermometer drops. I filled some 20w50 in my HIPO clone the other day and it came out like King syrup, reminding me to change to 10w40 if I want to drive it before April. 

My Dad always swore by 10w40 as a good all season oil. I use that in my restored cars, that have no performance enhancements..