Mineral or Synthetic

[Paul Shepherd]

Without wishing to start another oil debate I would like to know what everyone is using. I am using synthetic but looking at previous posts most seem to favour mineral so I am wondering if I should switch and why. I have a 86 911 that is 100 percent dry as I have just done all seals and tubes etc

[Duc Hunter]

Just done this search myself recently. Most here seem to say dino oil only on these cars, esp if they have not been freshly rebuild. Something about the zinc in that oil lubricating the tappets etc., and reduced leakage. If you check around there are recommendations for oils, there is Valvoline VR1 non-syntheitc many liked for its high zinc content, and other things.

Of late I have been looking at Schaffer Oil. Small and OLD american company. Many examples of where it REALLY helps engines, though it is a synthetic, which many will scoff aft for these motors. I am going to drop it in my BMW X5 Diesel and probably my 996 Turbo. The 3.2....not so sure yet, as she has 102k miles on the clock right now.

[wayne robson]

see--- page 4, 400k miles by chuck H, great story.

[darrin]

I BELIEVE much of the mineral v synthetic debate re leaking seals stems from how mineral oil reacts with seals and causes them to swell slightly over time. Switching to synthetic (or different viscosities) can cause the swelling to abate and create leaks where they weren't previously. OTOH, if synthetic is used from the getgo (on a new engine or after a rebuild), seals will not swell/have this issue. Zinc and its beneficial effect for flat tappets/etc. is another story altogether. I used to run mineral until my top end overhaul and have been running synth with mineral leakage for the past 80k since my top end

[sand_man]

Synthetic

[Ronnie's.930]

Synthetic

[Trackrash]

I've tried both in my '71. Synthetic leaks and costs more. Dino works just fine.

I would only recommend synthetic if you are seeing oil temps regularly above 200 deg.

[Koizumi]

I've used synthetic since rebuild with excellent results. I switched to partial synthetic Brad Penn aka the Holy Grail oil, and it makes my engine tick loudly and it leaks. NOT happy about this & gents, I really wanted to be happy about Brad Penn. It's back to stupid expensive Mobil-1 V-Twin soon.

[GeorgeM]

Originally Posted by Koizumi

I've used synthetic since rebuild with excellent results. I switched to partial synthetic Brad Penn aka the Holy Grail oil, and it makes my engine tick loudly and it leaks. NOT happy about this & gents, I really wanted to be happy about Brad Penn. It's back to stupid expensive Mobil-1 V-Twin soon.

First I've heard of anyone having that experience - sorry to hear. No issues with BP here, before or after rebuild.

[sand_man]

Originally Posted by Koizumi

I switched to partial synthetic Brad Penn aka the Holy Grail oil, and it makes my engine tick loudly and it leaks. NOT happy about this & gents, I really wanted to be happy about Brad Penn. It's back to stupid expensive Mobil-1 V-Twin soon.

Meh, I think something from Motul would be more "holy grail". I ran Brad Penn for a number of oil changes in my 930. I got sick of ordering it online and switched to the V-Twin, which I can always find locally.

I run V-Twin in my 993. However, being that my car is a daily driver and does see some use during the winter months, here in NC, I've decided that something more 15W-50 would be better...so I've got a case of Joe Gibbs DT50 (15W-50) sitting on my bench for the next oil change.

EDIT: so looks like I might be back to ordering online!

[Koizumi]

There's something about BP and my engine. I used previously Valvoline partial blend and the engine was silent. Same with the VTwin. I'll just go back to Mobil1. I've been using it for years with my BMWs. The VTwin however is expensive oil. And these Porsche BMW cars love 12 bottles of it too.