Which Engine Oil

[Westy]

So what’s the best type to use, so many conflicting reports online.

78’ Targa

[bjmullan]

I'm sure you will get lots of different answers here as well including people's preferred brands but keep it mineral and 20W50 and you should be fine.

[Sam]

I agree.

Anything all thin and syntheticky will just fall out of the gaps and make a mess on your drive.

I like Valvoline VR1.

[Ashley James]

I agree.

Anything all thin and syntheticky will just fall out of the gaps and make a mess on your drive.

I like Valvoline VR1.

That’s nonsense because synthetic oil has higher viscosity at higher temperatures.

The advantage of fully synthetic oils are as follows.

1. Doesn’t dissolve with petrol as easily, so less wear on bore and top rings.

2. Maintains viscosity to higher temperatures as might be encountered in air cooled engines.

3. Withstands higher temperatures and pressures, so reduces wear on cams, tappers, bores and rings etc.

4. Lower viscosity when cold means quicker to reach vital parts on start up.

5. Clings to surfaces for much longer so protects infrequently used engines better.

There’s a Mobil 1 information video on YouTube debunking popular myths and most manufacturers endorsed it when it first appeared. BMW tested a 328 in the seventies for 1,000,000 miles and found almost no wear. R-R announced that any engine they’d made would probably not wear out again after a rebuild and so on.

For Porches it’s best to use a fully synthetic oil for racing or old engines because they have more ZDDP to allay those fears.

I use Mobil 1 10W60 in my 356 and Porsche put Mobil in my Boxster as recommended.

[Lightweight_911]

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I don't currently own a 911 but my preference was always Valvoline VR1 20w/50 ...

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[hot66]

Used VR1 for the last 10 years + after recommendation from a number of different engine builders ( not all Porsche either )

[Gary71]

I use VR1 as well and it gets out of the gaps just as well as any other oil!

[jb]

I use VR1 too although I used Millers fully synthetic 10/40 for years.
I am out of my depth but the zinc content is apparently a good thing which makes VR1 a favourite

[alastairp]

Fasten your seatbelts and hang on tight - this is going to be a hell of a ride.......

I use Mazola and find it works fine as long as I change it after each use.

[acclassics]

It depends on your exact engine, I don't mean what year. I mean what condition is it in...

A fully or semi synthetic is great, if you do 10000 miles a year, and/or regularly drive the car with an oil temperature around 110 to 120 deg C, and/or you have a recently rebuilt engine.

If you engine has broken or pulled head studs, only does a couple thousand or less miles a year, or leaks, then depending on your oil pressure (good or bad) then either a mineral 15/40 or 20/50 will be just fine.

[Ashley James]

Here’s a video debunking the usual myths.

https://youtu.be/RpwrlWJMd40

Fully synthetic oil is a major advance over old fashioned mineral oil in that it really does virtually eliminate wear.

The last time oil improved so dramatically was the early fifties when Shell X100 dramatically reduced engine wear. Shell supplied it to many of the racers of the day, claiming that it would outperform Castro R. It took another twenty years for Castrol R to fade, but engines that had been lasting 20 to 30K suddenly went twice as far.

Now engines last extremely well anyway it’s hard to see a benefit, but it’s there for those who like reassurance. Any make of fully synthetic oil will do but it needs to be for racing engines or older ones. Both are more highly stressed.