Synthetic or not?, What weight oil should be used? Options

[Jake Raby]

I ran Royal Purple in the 160,000 mile engine in my 912E for every one of those miles. See this link for a full tear down evaluation of this engine after 160,000 miles of abuse and neglect. You will be amazed!
http://www.aircooledtechnology.com/index.p...&Itemid=112

That was the "old" formulation that was available before it was found in every generic parts store in the USA.

Today's RP has changed, the old stuff used to have 3,600 PPM of Moly and 1600 PPM Zn, today the figures are no where even close to that. The current offering of Royal Purple doesn't meet my standards and hasn't since around 2008. The UOA made it very evident where the changes occurred and when. Like all oil companies; they don't tell anyone when they change a formulation, because they don't have to.

I got fed up with taking what we were supplied and automatically the whole engine program benefitted from this. I hate the unknown.

An aircooled 911 engine has a totally different demand for an anti-wear package than a flat tappet equipped TIV engine does. I have attained UOA from the VR1 and it is not a bad oil at all, however has issues with fuel dilution that can create issues with engines that have poor ring seal at temperature, like the Type 4. I have seen as much as 4% fuel intrusion in a VR1 sample in a 3,00o mile service interval with VR1, that same engine with our oil had less than 1/2 that amount of intrusion with zero changes made to the engine. The VR 1 is a race oil, it is not designed for 3,000+ mile oil service intervals.

This post has been edited by Jake Raby: Aug 23 2011, 03:11 PM

[partwerks]

Here's the skinny. I have an unmolested 1971 1.7 with original FI. What oil should I be using in this car. Brand, weight, etc.

Whatever brand of synthetic is on sale is what I've used over the years. Typically, it is Mobil 1 or Castrol.

[ChristopherB]

I am wondering what this all means for me as my car has a Webb Racing cam with Hydraulic lifters. The previous owner told me to only use conventional oil. Anybody want to chime in and give me some advice? I need it! I have only had the car a few months and I am no mechanic.

[pete]

Let me preface by saying I'm not an Amsoil rep. I have large air compressors at work which I was running synthetic oil from the compressor manufacturer and ever so often they would seize up. I switched to Amsoil and never had the seizing problem again. I have 2 stroke dirt bikes which would foul plugs regularly and since I switched to Amsoil 2 stroke I have yet to foul a plug. I run all my 2 stroke yard equipment on Amsoil and they are still running 10 years +. I would LOVE to say I'm running my '74 teener on Amsoil but its still up on jack stands. If your going with synthetic, get Amsoil. Its about the same cost as Mobil 1 but it comes out a lot clearer.