Official "What oil / additives should I use" topic

[Gamba1973]

Hiya guys, well after over an hour of reading...... I am.no closer to making my mind up for an engine oil for my 1300 60s engine.

I live in western Australia and have been recommended this, what are your thoughts?

https://www.supercheapauto.com.au/p/penrite-penrit...lsrc=aw.ds

Thanks.

[Glenn]

[Wildthings]

Both straight weight oils and synthetic oils will handle heat better than dino multigrade oils. Run the thinnest oil that will give you adequate oil pressure which is around 0.7 Bar per 1000 rpm for a hot engine.

This is the lubricant chart for a 66 Type 1 engine, note that VW was not recommending a particularly thick oil.

Also note that modern oils are a vast improvement over the oils of the 1960's.

.

[KingAir42]

It’s been 114F everyday for the past few weeks. My 1200 40hp uses 30 weight oil. The hottest oil temp I have ever seen while driving around in this heatwave is 218F
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[oprn]

I normally run 10W30 in my Buggy. The oil pump is not new due to availability of proper oil pumps (type 4) but was just inside wear limits. Normally in the summer it runs 35 psi and 220*F at cruise. Last week I did an unintentional oil change on the side of the highway and the closest available oil I could find at the time was 15W40. It takes nearly twice as long now for the oil pressure to come down off the pin on cold start up, runs 45 psi and 240*F at cruise.

The only other gasoline engine I have run 15W40 in was a used Chevy 350 pickup the bearings were worn so bad in that it didn't have enough oil pressure to keep the lifters from collapsing once warmed up. The heavier oil did the trick for light duty service for quite a while.
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[oprn]

[Bruce]

[wcfvw69]

[bnam]

I’m newly reading this thread so forgive me if this question has been asked and answered before,

In an engine with a well regulated cooling system, the engine temperature remains the same (+/- 10F) whether it is 70F outside or 90F or 110F. So, why is there a need for hotter grade (say xW50) oil? Engine temp is anyway much greater than ambient. I’ve read that engines are typically designed to need about 10 centistokes at operating temp (100c/212F). xW30 and xW40 would seem to more than meet that need.

Thx,
Byas
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[Wildthings]

[hobthebob]

Sorry! I posted this in another thread, but I wanted to know what you guys think of this guy and his video on oil?


Link

[vamram]

Hmm...can't wait to see the comments. I'm no expert. I use QS full synthetic 5w/30 Dextros 1 on my year-round daily driver '73 1600dp in all temps, nothing fancy. I've *never* had pressure or oil temp problems on this car.

[Edit: Pet-peave: why do so many youtubers always fly their hands around the screen so it becomes the main focus of the video??? ]
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[Bruce]

[Wildthings]

If one runs a 50wt oil the engine will require more oil pressure to get the same volume of oil through the galleys and to the bearings than if you run a thinner oil, while if you have a stock oil pressure relief set up you will ALSO be bypassing the cooler and potentially dumping more oil back to the sump if you make too much pressure, so the actually oil volume to the bearings can be reduced significantly with a thicker oil. Measuring oil pressure just doesn't tell the entire story, VW gives a spec for oil pressure for 30wt oil, so if you were wanting to run a 50wt you would have to have a higher pressure to get it the same amount of oil to the bearing, which might well mean the VW oil pressure relief/cooling system is going to let the oil bypass the cooler and get hotter.

I remember decades ago plugging in the numbers for all the variables of the lubrication system on a then new engine using an accepted engineering equation and coming up with 30wt as the oil that would give the best all around results as far as journal bearing life. I doubt if much has changed since.

I you have loose bearing clearances then you may need a thicker oil to make up for the slop.

[vamram]

[oprn]

I don't know if it has been covered here yet or not but for all you heavier is better folks I am seeing ads now for 60wt "racing" oil.

Not my cup of tea but some may want to try it. It's gotta' make your car faster... no?
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[modok]

Finest crash course on the subject I've ever seen.
Welcome to the future, it's not so bad
And mobil one classic looks pretty legit
https://www.youtube.com/watch?v=a3uXSI9wQv8

[Bruce]

[jim martin]

just chucking it out there, just a different way to look at it and save time with the guessing game.

doesn't anyone measure clearances anymore ?
its kinda the first step in picking a oil weight .
then run it and monitor pressure .

for example my last motor ran main clearance of 0.005" .that motor ran 20w-50
on yearly inspection all bearings looked as new .pressure was ok .

new motor mains are 0.0027" ,will due the same fire it up on 30w and check oil pressure when oil is 200 deg .and in theory will drop down to 10w-40 and again run it an check , simple .

if you don't know your clearances , fire it cold get your idle and driving pressures cold . watch pressures during warm up then when its real hot .
recheck those idle. and say 3500-4000 rpm pressure .you will know if you need to go up or down on your oil weight choice.
knowledge is power .
and you want to save fuel run a 0w-20 .


bearing Oil Clearance Chart for reference


https://cdn.shopify.com/s/files/1/0827/6783/9538/f...1697433294
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[modok]

IT'S TRUE
I mentioned it on page 181
And, here:
https://www.thesamba.com/vw/forum/viewtopic.php?t=467803