Any scientific information (as compared to urban legends like the 'cool collar')that the high mileage dino oils (75,000+ miles) offered these days provide any substantive benefit over the regular dino oils? Thanks in advance!

 

I have been reading mixed views on long term use. However I am considering trying it once as a treatment to reduce oil drips. This is not what it's designed to do, because there are the same additives set up as one time treatments as well.

The alternative for me is an expensive re-seal job. I will try almost anything to postpone that kind of service. Sooner or later, if you have drips you will need new seals. All you can do is try to buy time I guess.

Note: I have read that these oils may make your engine run a little hotter. Also some people say it actually increases leaks. No concensus that I know of.

 

From all the posts on oil here you must realise that the consensus is to use the recommended oils and change the stuff at regular intervals. Other oils may last forever in a lesser engine but 911s are high performance engines and as such deserve the best oil you can afford if you want to retain it's performance. If you want to do a 75,000 mile experiment on an engine oil don't try it in a 911. Whether the oil is Dino, Mineral or Peanut oil it should be changed at least every 6,000 miles according to current opinion. My '78SC owners manual has oil changes down for 12,000 mile periods and whilst I don't pretend to know better then Porsche I'd feel uncomfortable keeping oil in there over about 6,000 miles of use. Maybe today's owners are too fastidiuous . If budget is a real problem economise elsewhere , the engine's reliability is not the place to save money.

 

I agree with Bones, but have the same questions as the first two, above.
Purely coincidentally, I emailed Castrolusa.com earlier this week via their "ask an expert" option, on what oil they would recommend... the high-mileage, their new "start-up" oil or their regular dino or synth/blends, for a mid-80s Carrera.
I didn't get a reply yet today.
My indep Porsche mech swears by regular Castrol (20W 50 for summers here).
Some earlier posts here and on Roadfly.Org mostly suggest staying away from synthetics for the 80s/older 911 (but the opposite for the 90s/newer).

Given how the oil sits at the "bottom" of the boxer-style engine and the fact that I run the car maybe 2-days/week, I am especially curious about the fru-fru "start-up" oil Castrol just launched. I think it is pretty well established that cold-ignition is the worst moment of wear for any engine. But is buying the doubly-expensive "start-up" oil simply equivalent to popping a quart of dura-lube/prolong/slick-50 in with the other 10 quarts of regular dino oil? Is it even safe/merited for a Carrera/SC?
I will let you know what they say if/when they respond!

Interestingly, when I tried Castrol's "find the oil for your car" option, it spit out "15W 40 Heavy Duty." And then said, they don't carry such viscosity and suggested I explore other brands. Yes, I input'd (is that a word) my year and model info... twice. Odd result, no?