ive been running 20w50 VR1 as that's all I could find locally on the shelves that was VR1.  VR1 does not offer a straight 20w oil which is what my shop manual indicates as the highest weight oil recommended for above 32*F with 10w oil being recommended for temps between -10*F to 30*F.

My only option VR1 wise would be 10w30 which would be more appropriate but I just don't know about that 30 weight viscosity when hot as that is still too much I think over the 20 that they recommended for these engines.

shop manual states a API of MM is recommended for all engines including thunderbirds MS for police interceptor engines.  Im going to spend the day digging on this as I am going to be doing my oil change soon as this oil is kinda old year wise and its time to make the change.

Just be advised the SHOP MANUAL is calling for lubricants available in that time period. A lot has changed and all of that info is well out of date.

A 20W-50 oil is for racing only whereas the engine has loose clearances and uses fuel(s) which dilute the enough as to  where it needs to be changed very frequently. That is why the cleansing packages are left out as the oil may be dumped between runs.

All depends now on lifter type (and modern hyd lifters can use excessive springs pressure also), assembly/wear clearances and length of service life. You need to keep records of service intervals, make-up oil and record start-up oil pressure @ idle to keep an eye on it. If the engine is very valuable, say a BIRD restoration, an oil analysis at change would give you the best idea of how the oil is performing.  Don't forget proper fuel ratio and state of tune. along with correct CCV.

And above all a good quality oil filter.

Like Charlie said, a 10W-30 for normal use and possibly a 10W-40 if it really gets hot down there. Just keep a good eye on the pressure gauge (mechanical quality).

(All of the above is IMO)

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For me I would have to rely on the light as I didn't want to go added aftermarket gauges.  Temp wise summers can get up to 105*F in some cases.  winters coldest ive seen it get was 28*F.

For me this is a old engine that will be used as a driver.  when it comes time for a rebuild it will be stock to be used as a driver still.  So for me longevity is what I seek as I don't want to have to do engine work every few years for the driving I want to do.

For now ive been changing the oil every 1 to 2 years as I don't drive the car but I try to run the car once a week.  Now that I will be driving I will be keeping a mileage record and will do oil and filter changes at the recommended 2,000 mile intervals.  which for me 2,000 miles would take about 6 to 9 months to achieve.

Filter wise I always run a FL1A motorcraft filter on my fords and run the proper AC delco filter on my scrubrolets.  I don't believe in using fram, or wix, or purolator or any of these other brands.  I use OEM branding.  Only time ive used purolator is for an airfilter for my truck as the motorcraft  air filter was not available at the time.


1956 Ford Fairlane Town Sedan - 292 Y8 - Ford-O-Matic - 155,000 mi

Kultulz, I appreciate your information and knowledge. Can you give us the names of these more current products that would be the best performers in our old Y-Blocks? Thanks.

Bob, I am no-one special believe me but LUBRICANTS have changed drastically and some refiners are saying things that not might be as true as they should be.

READ THIS - https://www.enginebuildermag.com/2016/04/high-performance-engine-oils/

It explains it better than I can.

BTW- VALVOLINE is a QUALITY PRODUCT. I did not mean to imply it isn't. You just need to know what product you need for what you drive. There is a huge difference between RACE, HOT STREET or PASS CAR/TRUCK engines.

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For me this is a old engine that will be used as a driver.  when it comes time for a rebuild it will be stock to be used as a driver still.  So for me longevity is what I seek as I don't want to have to do engine work every few years for the driving I want to do.

For an older engine (not recently rebuilt), you can also consider HIGH MILEAGE OIL. Check the VALVOLINE WEB PAGE for info.

I am hung on HI-PO for some reason.

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Oh I fully understand what you are saying.  I know you aren't saying Valvoline is a bad brand.  For me its just trying to get the right stuff for my application.

It just sucks cause I am content with running VR1 but I kinda of prefer a straight 20 weight oil like owners manual calls for but maybe that's just me being a stickler for the rules.  Ive always ran 10w30 in my vehicles except for my old ford truck I ran 20w50 in that cause it was the only way to keep the knurled valve guides from causing excessive oil consumption.

In this case I think 10w30 is what I will run.  I can get a case of 6 quarts from amazon for $12 of VR1 10w30 but its a 1 to 2 month shipping time and I really want to change my oil sooner than that since this oil is about 2 years old now.


1956 Ford Fairlane Town Sedan - 292 Y8 - Ford-O-Matic - 155,000 mi