Hi to alls
A good mechanic told me about SAE 20W60 oil and praised its benefits for old engines. Here's what I found on the subject.What do you think about these considerations?

SAE 20W60 oil offers several advantages, particularly in specific usage conditions. Here are some of its key benefits:

1. Excellent Wear Protection
   • High Viscosity at High Temperatures: The high viscosity at high temperatures ensures a thick oil film that better protects engine components against wear, even under high-temperature operating conditions.
2. Versatility
   • Multi-Viscosity: The 20W60 classification means the oil has good fluidity at low temperatures (20W) while offering high viscosity at high temperatures. This allows the oil to function effectively across a wide range of temperatures.
3. Oxidation and Thermal Degradation Resistance
   • Thermal Stability: SAE 20W60 oil is formulated to resist oxidation and thermal degradation, prolonging the oil's life and maintaining its protective properties longer, even under high heat conditions.
4. Leak Reduction
   • Thick Viscosity: Thicker oil can help reduce oil leaks in older engines or those with worn seals, ensuring better sealing of components.
5. High-Performance Engine Protection
   • Ideal for High-Performance Engines: High-performance engines, especially those used in motorsports or motorcycles, benefit from the extra protection offered by a high-viscosity oil like SAE 20W60.
6. Compatibility with Older Engines
   • Older Engines: Older engines, which may have larger internal tolerances due to wear, can benefit from thicker oil to maintain good oil pressure and effective lubrication.
7. Maintaining Oil Pressure
   • Pressure Stability: The high viscosity ensures the maintenance of oil pressure even under heavy loads and at high temperatures, which is crucial for engine protection under extreme operating conditions.

In summary, SAE 20W60 oil is particularly beneficial for high-performance engines, older engines, and in high-temperature operating conditions, offering excellent wear protection, good thermal stability, and reduced oil leaks.

 

Read this entire thread. I am a Tribologist with a Supermajor oilco. A 20W-60 is ridiculous. Jaguar never recommended any Viscosity over SAE 40 in Tropical conditions. SAE 30 in Summer. SAE 20 in winter.
Engine Oil - Page 3 - THE INTERNATIONAL JAGUAR 'S'-TYPE REGISTER FORUM

 

I used to use 20W50 oil in my 3.8 but more recently have been using 15w40 and the engine is much happier. The oil pressure remains excellent.

 

The only problem with 15W-40 is the ZDDP restriction. In Winter a Synthetic 5W-40 is ideal & in Summer a 10W-40. REMEMBER THEY ARE SAE 40 at operating temperature. The highest recommended by Jaguar.

 

Refresh page for diagram.

 

just another oil thread... there will be no agreement i'm sorry to say.

 

I would listen to Jaguar. There should be no argument unless your engine is buggered and ready for rebuild. The British 20W-50 was designed for Sir Alec Issigonis Mini, Austin 1100 and Landcrab (Austin 1800) with combined engine & transmission.

 

15W-40's had a zinc restriction placed on them to sacrifice engine & save the emissions equipment. Don't worry now from the majors. We have formulated our way around it. Zinc is not the only component that protects cams & tappets.

 

So called "Classic Car Oils" are rubbish. They are formulated with cheap base oil, non shear stable VI Improvers (US ~ Viscosity modifiers) & they have the cheek to charge a premium for them.

 

Ladies and gentlemen, my humble unworthy two cents worth for your edification and enlightenment.

Attached is a scan of my 1965 3.4 and 3.8 'S' Models Operating, Maintenance and Service Manual (Recommended Lubricants, page 52). Note the Duckham and Regent (Caltex/Texaco) 20-50 engine oil recommendations, also included is another image of the Preferred recommendation by 'Penrite Oils' for the ((my words,) "original and best") Jaguar S Type.

P.S. I have run another Penrite product, Penrite HPR30 20W 60 in my 1972 Norton Commando, my 1982 Triumph Bonneville and my 1967 BSA B44 Victor Roadster for some years now with excellent results. NOTE! All old tech flat tappet engines!

 

With the greatest of respect newer thinking. I'm a Tribologist from a Supermajor oilco. 1972 Manual for 1965 3.4 or 3.8 S Type. So called "Classic" oils are rubbish as explained above. Jaguar from day one of the XK engine have never recommended anything over an SAE 40 engine oil in tropical conditions and an SAE 30 in summer. Penrite has been wrong for years.









Take a close look at this plate & take a guess which famous racing Jaguar it's from.

 

Refresh page for Edits.

 

To add to Glyn's words: there wasn't a wide range of multi grades available in the 1960s and given that, for most users making an annual oil change, a multi-grade was probably better than a mono-grade, vehicle manufacturers could recommend only what was available. Further, I suspect the VI additives didn't survive so well and a 20/50 may well have become a 10/40 after a few passes through the oil pump. A good, modern synthetic from an oil major will be an altogether better proposition.

 

The 20W ~ 50 so called "Classic" oils as Orlando can attest from trying one from the above-mentioned company sheared to an SAE 30 in proper oil sample analysis and his oil pressure dropped below the good old 40 psi in the recommended Jaguar test. This on a newly rebuilt engine. This was hastened in the Sir Alec Issigonis cars by the gearbox chopping up the VI improver. This is why I still recommend Plastigauging all your bearings at rebuild.

 

On no account use these oils as sold by the likes of Barratts. They were all that were available in the UK at the time in Multigrade other than Texaco (Chevron, Texaco & Caltex ~ Californian Standard Oil originally New Jersey (now Chevron), Texas Oil Company hence CALTEX JV after anti trust break up of the Rockefeller empire that even owned the railroads ~ Wealthiest man in America) are merged today and were always the same group of companies. To look after the Mini, Austin 1100 & 1800. If you choose to be silly enough to buy, (at a premium) then change every 1000 miles Maximum. Even available in 1 Imperial gallon. What does XL mean? GBP 42.89. (sorry my keyboard does not have a Pound sign)

 

Refresh with price for junk.

 

Refresh for further explanation.

 

Glyn, for a British Pound sign, hold the "ALT" key down and use the key pad and punch in 0163 £
Has to be the key pad to the right of the key board, the numerals on the top row doesn't work.
Make sure the "NUM LOCK" is "ON", if it doesn't work.
This works pretty much all the time, with the exception of some out of date web pages and forums.

 

Thanks Jeff.

 

£ ~ Ha it works.