Bad news for Dino oil users...

[pwd72s]

HOT ROD, August 2002 issue. A chassis dyno test was done on a car. 1st run using Dino oils in engine, gearbox, and rear end. HP was 408.3, torque was 405.1. Then same car, no changes other than conventional lubes changed to synthetic. Horsepower 418.4, torque 411.2. A quote from the article: "They're (synthetics) a bunch more expensive, but in our opinion, they're worth it in cars you care about. For your $200 Pinto, stick with the 99 cent stuff." So, I conclude that if you care about your 911... Now, let the debate begin...

[rstoll]

10 horsies???? That's a lotta friction.

[pwd72s]

That was one of the points made in the article...less friction means less wear, means longer parts life...

[Jim T]

That's about 2.5% more power, assuming their very non-scientific dyno tests have real validity.

As far as long engine life, hmmm, my 914 went 225,000 miles on dino oil (including many early years on straight weight, non-detergent oil, not changed very often), 911s routinely do that and a lot more on dino oil and semi-regular oil changes.

If you use good dino oil, changed at 5,000 miles, I just don't think you are going to have an oil related problem during the time you own the car - so the synth. won't get you anything.

99.something% of 911s will pull headstuds, get crashed, sold to another person, etc. etc. etc. before suffering from an oil related failure that could have been prevented by using synthetic oil, I would guess.

Thus, I think for the vast, vast majority of people, spending additional $$ on synth. actually will never result in any return on the investment.

[Jim Sims]

The rough expected statistical variation for a 400 horsepower test is plus or minus 20 horsepower (square root of N rule). Therefore, I would not get too excited about a 10 horsepower gain or loss. Also, was the test protocol the same for the synthetic test? Would the results be different if the synthetic test was run first with "relatively colder" engine components? If there were 10 tests of each condition randomly intermixed then the difference comparison would be more useful. Not all the horsepower loss is going into sliding or wearing friction; some of it is going into shearing losses moving and pumping the oil around. Differences in the actual oil viscosities may account for much of the horsepower loss difference not sliding friction. I haven't put 99 cent oil in anything lately even my '85 Blazer. I also cringe at the thought of how much NM dust (and Arizona smoke particles) would be in my oil if I ran it for the synthetic change intervals! I'll stick with the Castrol GTX 20W50; well, at least until I install new seals at some future engine rebuild. Cheers, Jim

[Doug Zielke]

Originally posted by Jim T

99.something% of 911s will pull headstuds, get crashed, sold to another person, etc. etc. etc. before suffering from an oil related failure that could have been prevented by using synthetic oil, I would guess.

Even though I'm an advocate of synthetic oils, I agree with Jim's comments. Now, race cars are another matter......

[makaio]

Paul, what kind of oil was it?

[pwd72s]

Another quote: "First we made a series of runs on the Westech Performance Superflow chasis dyno with 20W50 in the crankcase, Dexron III in the gearbox, and 75W90 gear oil in the transloc differential.....THen we drained the petro-chemicals and replaced them with man made hydrocarbons from Royal Purple: 7 quarts of 20W50 synthetic engine oil, 6 quarts of max ATF, and 2 1/2 quarts of Max Gear 75W90. After a five mile jaunt to get everything up to the same temperature as the baseline test, we let it rip." Have to admit, I've never heard of this Royal Purple brand...is it a California region thing? For what it's worth, HOT ROD believes there was "an impressive tribute to the reduced coefficient of friction"....

[makaio]

I have heard good things about "Royal Purple" in the hot-rod mags. It's kinda of spendy though. Like $7-8 a quart if I remeber.

[pwd72s]

Matt, I'm giving my age away...the last motor oil I remember with purple dye? It was called "Royal Triton"...sold at the old '76 Union stations. I used the stuff in my '65 GTO...

[TRE Cup]

royal purple seems popular in the east- several speedvision cars from back there ran the stuff. don't know much else about it.

[ChrisBennet]

I saved this from From Rennlist in 1998. I found it very interesting.
-Chris

Subject: synthetic oils
From: "Brian E. Buxton"
Date: Tue, 3 Nov 1998 17:17:55 -0600
X-Message-Number: 69

This was posted on the 929 list and I wanted to get some thoughts on it.

BEB

"Hi All,
Kinda long, sorry ....

I've noticed the recent inquiries and responses to "winterization" questions
for the 928 and thought I'd offer an unsolicited comment. Within the past
week I have been made rudely aware of what *not* to do for engine care
during the winter. It may or may not apply to the 928. Just use it as
additional information to add to your knowledge base. I live near Portland.
Oregon where the winters are not particularly cold, but do tend to be damp,
rainy, and foggy at times.

Here is what happened. I also have an airplane which resides in my garage
with the cars. The garage/hanger is mostly unheated. I fly some during the
winter, but not a lot. I always fly enough to heat the oil when I do go out.
A few years ago, I began using Aeroshell 15W-50 semisynthetic aircraft
engine oil.

Reasons were the usual ones for using synthetic based oils, and I noticed
immediate reduction in cylinder head temp, smoother operation, reduced fuel
consumption, etc. I have all digital engine gauges including fuel flow which
is accurate to 0.1 gph so these improvements were actual, not seat of the
pants feelings. I changed the oil at regular intervals - less than the
recommended time. The Shell semisynthetic is especially formulated to
inhibit corrosion. At least that is what the Shell specs say. Conforms to
FAA specs., Mil-Spec., engine manufacturers approvals, etc., etc.
Supposedly, the best money can buy.

One cylinder was down on compression due to a leaking exhaust valve so I
removed it for repair. What I found was not pretty. Rust pits!! Rust on the
cam. Rust on the can followers. Rust on the piston pins. Rust on the inside
of the cylinders. I have not removed a rod cap to check the crank, but I
fear the worst. These rust pits are through the hardened surface so service
life will be short and the engine must be removed, torn down, and all rusted
corroded parts replaced. The basic engine overhaul cost is estimated at
$14,900. That is with me removing it, and re-installing it. No accessories
like carb, magnetos will be touched for that price. If the crank is bad, add
another $6k to $8k.

The engine shop said, "We see that all the time when people use synthetic
oil and don't use their machine regularly. The synthetic flows off the
internal parts and leaves them open for condensation moisture attack". They
recommended to only use synthetic oil if the engine will used continually.
If it will not be used much during the winter, use regular, non-synthetic,
oil; something that will stay on the surfaces. Here I thought I was doing
all the right stuff to take the best care of the thing and It was not right
at all. Wish I had known then what I know now. |

I guess it doesn't matter much, but wear on the parts, excluding corrosion,
was nil with about 800 hours on the engine. This may not apply to auto
engines or auto engine synthetic oil, but it seems like it shouldn't be too
far off.

If you live where condensation is not a problem, ie. dry and usually below
freezing, then this probably wouldn't be a factor. Yes, both the 928s still
have Redline oil in them, but will be used regularly. As always, YMMV. Back
to the garage now to spend my Sunday afternoon removing cooling baffles,
exhaust pipes, and lots of other stuff."

cut and pasted from an E-mail by louis ott to the 928 list

[Jim Smolka]

I with Jim Sims on this one. Once again, poor test procedures.

To gain a perspective on the inherent invariability of the system, numerous testing in a random order (w/Dino and w/Synthetic) is required to 'correctly' determine magnitude of the main effects and the 'noise' in the system. Again, correlation does not prove causality.

The folks that go through the trouble of doing these tests need to consult with statisticians or others who are knowledgeable in experimental statistics. Without proper testing procedures, one cannot accurately draw conclusions about data gathered.

[pwd72s]

So, a question to the dino oil fans? Are you trying to say that we who have switched to synthetics are hurting our cars? Or, are you having trouble admitting that we just may, just might possibly, be helping them? I'm willing to pay more for only a possibility...just my decision.

[Gspin]

What get's me is the number of people that dispute the benefits of synthetic lubricants. I'll bank on the engineers at Porsche they have the test data and the formal education to back their recommendations.

If that still isn't enough for you walk around the pits at the large race events, AMLS,NASCAR,NHRA,etc. and see what these guys are using.

Last, perfrom your own in home test. Take 2 qts of your favorite brand of dino oil and put one in the freezer and the other in the refrig for an hour or so. Then take two qt's of any brand synthetic oil with fairly similar viscosity and do the same. Pull the bottles out the freezer and refrig and shake them. Notice how the thick the dino oil seems vs. the syhthetic oil. Despite the refig temp being in the 45F range it still will show some of the thickening that takes place with dino oil. The freezer makes matters that much worse. Now you will see why dino oil is so inferior in the cold temps.

[Jim Sims]

Off the top of my head:

Dino Advantages: cheap so you can change it often when it is contaminated with combustion products and contaminants from the outside enviroment (air filters are not perfect), doesn't affect traditional seal materials as much as synthetics, sticks to surfaces better than synthetics, not as "searching" as synthetics.

Dino Disadvantages: some increased wear especially if recommended change intervals are not abided by, breaks down at higher tempratures, harder to control viscosities; when the additives are used up (3000 to 5000 miles?) or it breaks down due to heat it's properties are significantly diminished, decreased fuel economy and power loss due to viscosity losses.

Synthetic Advantages: superior lubricating properties, higher temperature capabilities, properties are more consistent resulting in more taylored performance and reduced viscous losses (greater fuel economy and power output), can be run longer before properties diminish.

Synthetic Disadvantages: higher cost resulting in the tendency to leave it in the engine when external factors such as dust or storage dictate it should be changed, some formulations affected older seal materials causing leaks, more searching fluid so it will leak out through cracks and openings that would hold back Dino oil, running off surfaces of stored engines (a new problem to me but it goes with the searching fluid tendency).

Pick your poison! When I rebuild after using modern seals/sealants and then breaking in with dino oil I'll probably switch to synthetics but I'll probably change the oil filter every 3000 miles and lose the synthetic oil therein.

Jim

[Randy W]

This topic is going to be subjective, no matter what. All of us care about our 911 engines, or we wouldn't be here.

For magnesium case 911 motors, it is well known that the risk of leaks is greatly increased by using synthetic oils. For these motors any HP advantage with synthetics is a mute point. My experience tells me that Kendall GT1 (one of the best dino oils) will not create any new leaks in these motors and will perform well under extreme conditions, even with MFI's fuel dilution, provided the oil is changed every 1000 miles or twice a year. For aluminum case 911 engines, IMO Mobil 1 synthetic is hard to beat.