synthetic oil

[Rick Rockey]

This should be fun - I'm about to change to a synthetic oil. What do you think would be best, Amsoil or Mobil1 ???, and how will the synthetics blend with the small amount of oil (GTX 10-30) left in the system?

[MidOHasp]

Best probably depends on your viscosity choice. Based on a website I went to where flash point, viscosity index, pour point, and mineral content was studies, it looked to ME that AMSOIL was the best for 20W50 and Mobil1 for 15W50...

Maybe I can find that link somewhere...good info. Objective!

JP

[Excaliber]

I checked out that web site too and concluded I would go with 20-50, Amsoil 'cause I'm in a warm climate zone.

BUT, I'm staying with regular oil because I worry about the 427 FE compatibility issues with synthetic. Like old Harleys and old Jaguars it might make the motor "leak".

[Bob In Ct]

I use synthetic oil in 4 different cars, An 85 K car(0W-30), an 88 Porsche(15W-50), an 93 Taurus(5W-30) and my 2000 SPF(5W-30). It did not cause any of them to leak. I would favor the Mobil1 since they don't have 500 web addresses trying to get you to use their oil like Amsoil does.

Use the lightest weight which provides the pressure you need. This will maximize flow and cooling. Using 20W-50 with an oil cooler at street temperatures is tough on flow and cam gears.

Bob

[REDSC400]

I have been using RedLine 10W-30 synthetic in the winter when it is cold and Amalie 20W-50 synthetic Pro Grade in the summer when engine temps are higher. This is the regime that has proven to work well in my 428FE. Amalie is rather hard to find but if you call them up you can usually find a distributor in your area. Both are excellent synthetic oils however neither are they inexpensive.

The engine was broken in with non-synthetic oil for the first 5000 miles.

[ava8r]

I use Amsoil 20-50 here in NorCal and very happy with it.

Also it's in my other cars. Worth the extra money.

A2

[jschiller]

Here's a site conducting a long term test.

Might help in making the decision.

http://neptune.spacebears.com/cars/s.../oil-life.html

[Shawn C]

Is anyone using Royal purple in their engines? Or even transmissions or rear ends?
I use it our Heavy equipment and Tug boats, much better that petroleum based oils.
Dirty Ernie,
Call me if you want some, got lots.

Ciao,
Shawn

[Bruce Edwards]

Ok I have to put in my 2 cents.
I have one question but it may led to more that that.
Has anyone seen a side by side wear test with conventional oil and synthetic? In all these years I have yet to see a true engine side by side test. Why is that? Can not be due to cost. How much would it be to hire an independent lab to have two identical engines run side by side? One running say Valvoline 20/50 and one running Mobil or Amsol or what ever in a 20/50. Change the oil when recommended by the engine builder i. e. Ford,GM or whom ever for the conventional and changing the oil when Mobil one or Amsol says to. Keep a cost list of oil change cost say up to the equivalent of 100,000 miles. Tear them both down and measure all area's of wear and post the result for all to see. If the synthetic is all that wonderful seems like I would have seen this years ago. I have had synthetic sales folks come to my shop to sell me the stuff and have asked everyone of them the same question as yet have never had an answer.
I have had customers that love their Mobil 1 and use it from day one after break in. Have one customer that kept the car for 12 years or more and bingo at around 125,000 she started burning oil. Never did get a chance to tear it down to check it for wear as his son wreaked the car shortly after it started smoking.
Till then I will stick to what I know works over the long haul.
If any of you have seen a test like I am talking about PLEASE tell me were to find it.
Old school what can I tell you.
Oh and just for the record I have never had an engine of mine come back for an oil related failure in over 25 years of building engines using the "old" stuff.

[REDSC400]

Bruce,
You make an interesting point. On my daily driver, which I really take care of (1992 Lexus SC400), I change the oil and filter every 3000 miles which is about every other month. I run normal high grade Pennzoil 5W-30 in it, not synthetic. My typical drive is highway speed for about 45 miles one way.

The time intervals between my oil changes are short and the added expense of the synthetic is not worth it. The SC now has 120K miles on it and runs perfectly.

As I understand it, the synthetic oils and syn-blended oils have a few attributes which make them advantageous to use for some applications...

1) Light weight allows a nice film of oil to get between metal parts, resulting in more lubricity without loss of Horsepower.

2) Coupled with one above, superior high temperature viscosicty, the 5w-30 will stay 5w even at the high range of its intended use

3) Longevity - the synthetics are not supposed to break down as fast so their added expense is mitigated by longer oil change intervals.

4) Ability to provide lubricity when cold, especially good for what is known as "extream condition" driving, short one or two mile runs.

The reason I use pure synths in my Cobra is predominantly items 1, 2 and 4. I change out the oil twice a year. It comes out clear usually.

Cheers

[NeedAntiVenom]

Rick,

I use Mobil 1 and have been very happy with it. Here are some articles about long term testing.

Longevity test:

http://www.mr2.com/ARTICLE/Mobil1.html

Fleet test:

http://www.xs11.com/stories/croil96.htm

With a very expensive motor, I would rather be safe than sorry. The additional cost of synthetic oil is minimal in the overall cost of owning a Cobra. I would be very cautious about the informal test mentioned by jschiller, while I respect the test effort, IMHO it has too many holes in the monitoring/testing procedure and an inadequate baseline.

Jim

[Clois Harlan]

Ernie,

I am running Royal Purple Racing 21 Oil in my 428FE Engine. Just recently switched from Castroil 20w 50w and will be thrashing the ole hot rod around the Mid America Complex in Omaha next weekend for about three days. Jay Nordstram and Keith Williams have been running Royal Purple for several years now and seem very pleased.

I will change my oil each day and I should be able to get a pretty good reading from my System One re-usuable filter how the bearings etc are holding up. If I can remember I will post my opinion of how Royal Purple performed when I get back.

Clois

[Ron61]

I am not an expert on this but I talked to my engine builder yesterday and he said to use the Mobil 1 synthetic in my 428 punched out to 440. He told me they are using it in all of their racing engines and have never had a problem. Should get mine home today I hope.

Ernie,

Don't worry about leaks and dips. That is the trademark of a Ford FE engine. Just watch out for the steady stream coming out the bottom because of an oil pan failure. Some of the oil pans have been known to fail to hold broken rods and such inside.

Ron

[avanti-176]

when I sold my '92 Vette to buy the Cobra it had about
130,000 miles on it. Never had anything other than mobil 1 in it and did not leak or burn a drop and was just as strong as the day I got it.(drove it pretty hard too )
So from MY experiance Mobil 1 lives up to the billing and will be used in the Cobra until it fails me.

"if it ain't broke, don't fix it"

Have a good one,
Dan

[SN8KE]

Gentlemen: Every jet engine in the world uses synthetic oil (talk about your extreme service range). As for the comparison of Amsoil to Mobil 1, check this info out : http://www.amsoil.com/performancetes..._vs_mobil1.htm

Happy Spring !!

Bruce

[SCOBRAC]

It doesn't matter. All synthetics are far superior to conventional oils. Be prepared. on a molecular level what makes them superior also makes them prone to finding smaller passage ways. Including the ones you would rather not have. Asise from increased leakage you will be happier with synthetic oil.

I too use mobile 1. As does Calloway Ferrari, Porsche and GE (Jet engines)

[rdorman]

The oil stock itself never wears out. Both synthetic and non-synthetic. It is the attitives that give out (recycle it folks. the energy required to refine the oil in my car would power my home for 24 hours). To make a oil go longer between changes more or better quality attitives are required. A large part of the premium that you are paying when you buy any oil that claims to be extended change type oil.

You can stick virtually any darn oil you want in a car, change it reguarly and the motor will live a long and happy life.

So why do I run Mobil 1 in my Cobra? Because ........ I like it Seriously. I have heard/read a number of stories about the added protection, some on paper benefits and some real world benefits as well. Throw in my anal retentive nature and there you have it, I use full synthetic.

I have plenty of experience with both Mobil 1 and Red Line and none with Royal Purple and Amsoil. But there is no reason to think there is a problem with them. Mobil 1 is sold in more outlets and I watch it to go on sale and can usually pick it up for $3.75 a quart (anal and cheap!).

We used to run our formula ford race engines for an entire season on Red Line and never once had a failure. The motors "needed" only a basic freshning ever year. DV spun the bearing in DVII while doing skid pad testing using Mobil 1. What he discovered is that the car was running at 0 pounds of pressure during the test since the stock pan was not up to the task (ALL the oil was up in the outside valve cover during the skid pad runs). This was after a LONG day of testing. He swears that the damage would have been more substantial if it where not for the Mobil 1.

If you want to do your motor a favor, buy it the best filter possible and consider one of those two stage jobs. But, this will just make it last longer and how many of us are going to put 150,000+ miles on a Cobra motor without the little voice in the back of our heads telling us to rebuild the motor. I know I would rationalize the new motor long before then, sell the idea to the wife as proactive and then pull my perfectly good motor out and sell it to some hot rod kid.

Happy lubing!

Rick

[Bruce Edwards]

First off a jet is a sealed system. It is not open to contamination as in an internal combustion engine. I do agree that the oil does not break down it is the contamination due to the combustion process that is the problem and that is kind of the point I was looking to make.
The problem I have with synthetics is the cost and oil change intervals. The problem with an internal combustion is it is a dirty system. The rings leak hot gases, fuel, water gets in during cooling due to condensation and more. All of these factors cause a break down in the oils ability to lube the engine. After a time the oil can not hold any more crap and starts to deposit the heavier material in low spots in the engine. Know as sludge to some of us.
The amount of contamination any one product can hold may be up for debate how ever all will reach a saturation point. My big problem with synthetics is that I do not see a cost benefit from it's use in any way. I would rather change my oil at $20.00 or less every 3,000 to be sure I am draining out as much crap as I can rather than hope that the synthetic will hold all of those not good for the moving parts contaminates till they say it is due. The acid that comes from all of that stuff mixed in the oil going after the soft bearing material just ever seemed like a good idea to me.
Just for the record I have a 93 Bonnie SSEI with a 3800 that is Supercharged with 150,000. I change the oil every 3,000 and it comes pretty clean looking also. Does not use oil or leak. Never had to open it up. Have had to repair the supercharger twice but the rest has never been touched.
Or maybe I should tell you about my 73 Charger with the 340-6 that I would bang off of 8,000 at the track and also drove to work every day that also never had any dirty oil. I could pull a cover after 24,000 and it just as clean as the day I built it.
Again back to my original post. Show me a side by side then I will believe till then......

[flipper35]

I have seen comparisons replaceing the oil from the engine/trans/rear end and getting 22-27hp at teh rear wheels. Hot Rod did one with Royal Purple on a chassis dyno and a Corvette Newsletter did one with Red Line. The biggest change was going from regular gear oil in the diff to the Red Line Shock Proof. If I find the articles I will post them here.

[Bruce Edwards]

I have seen some in the past as well but they were taking out a heavy oil and replacing it with a lighter one. I guess if you do not mind all the noise and gear clashing it is worth it. I could put a light weight oil in the trans I build as well but if the trans was made for a heavy oil I am sticking with it. I just kind of figure the folks that designed it to start with probably had a good idea of what it should have in it.