IcemanG17

Amsoil racing 15-50...sure its pricey...but I have ran it for 18 hours on track in between oil changes during endurance races!! Even after 18 hours on track the analysis still came back perfect!!! It could have gone longer!!

bgiere

These types of discussions usually involve a lot of opinion and urban legend and very little factual info. The only way to tell if an oil is right for your car with your particular usage is to perform a series of used oil analyis tests. There are many labs that will do this. I have used pretty much every oil imaginable and obtainable! My UOA's look the best using Redline 10w40 and running it for 10-12 hours in race conditions. It can probably handle more. I am running the new "holy grail" this year, Brad Penn, in both the 944 and the 964 cup. We'll see how it tests after a few drain intervals. I'd say that any reputable race oil will most likely be fine with some adding a slight extra degree of protection in very extreme heat conditions. Most of todays oils are really very good and I would bet you see very few engine failures that can be blamed on lubricant failure. It was most likely an engine that would have let go anyways!

f1rocks

Another VR-1 vote. I figure most of us probably change the oil frequently enough we aren't getting anywhere near using up the useful life of the oil (in the case of some they burn it fast enough that they never change it...ahem Repka ) Can't justify the additional oil cost difference based on my change frequency

Even doing a 9 hour enduro weekend I'm confident the oil would be fine.

Also agree that it would take lab analysis to provide true data. Would love to see someone do a back to back comparison but difficult as load, temperature etc would all probably vary significantly.

Potomac-Greg

With 20+ year old cars that have changed hands multiple times, all you can do is use good oil and cross your fingers. If nothing's blown up, it's either because you have used good oil, or because it's gonna blow up tomorrow.

IcemanG17

LOL......the bummer is he's right......thats the risk those of us running "stock" motors face..... Shoot my "new" engine was quoted at 117k...but who knows really

amr89c4

Valvoline VR1 20-50 dino in 951 and the 964...its got the ZDDP levels required by the 89 964 and it gets changed every third event in the 951.

jaje

I'm now running Amsoil Dominator 20w50. I change it after about 4-5 track events. I also doesn't have the drop in oil pressure I would get when I was running VR-1 (but was changing oil after every event).

I was talking with local racers at the shop I bring my car in for work. I spoke with an SCCA guy who tested oil for Amsoil in his racecar. He would overnight them samples after each race event he did and would not change the oil until he was instructed. It wasn't until about 4k track miles did the oil deteriorate to the point it needed changing (pretty impressive to me)! It lasted him an entire season.

mrepka

Ummmm... Who me?

Interesting thread, I have no personal evidence that M1 is "bad" (nor do I that it's good) so I've continued to use it. I never seem to have the above stated pressure problems at the high temp, and all the internals that I've seen in my rebuilds certainly didn't indicate that the oil was not doing the job. But like Brent pointed out, we do change the stuff enough that saving a couple bucks per change could add up. Does anyone have any hard facts that they can post from oil analysis that would put an end to the debate?

Jay Gratton

Late to the party, but I am a 15-50 Amsoil Racing Oil kinda guy.

beentherebaby

Just a warning that a Used Oil Analysis, (UOA), is designed to tell you what condition the oil is in, not how well it performs inside the engine. A $25. UOA is excellent for determining the useful life of an oil so you don't throw perfectly good, expensive oil away. See Titan or Blackstone labs for reputable UOA.

I personally prefer a 5W-40 or similar viscosity oil for street/track use as it flows well cold and provides good high temp protection for many application.

Below is a link to an excellent article on UOA.

http://www.bobistheoilguy.com/cms/in...onth&Itemid=71

333pg333

Bob is the oil guy bends over and panders to the notions from someone with the initials DH. He has contradicted himself on various forums and seems to have shares in Mobil products from what I can observe. If you go onto BITOG and dare question the credentials or statements of DH you get booted off. Take care of what you read and believe. Some people espouse certain brands / types of oils with no experience in the field, let alone with flat tappet motors and ones that go to the racetrack.
Buyer beware....

VaSteve

Here's my analysis:

I use 15w50 Mobil 1 since that's what they guy I bought it from used in the car. I get it at Wal Mart in a larger Wal-mart-only sized jug that's actually a couple of bucks cheaper than at the Auto parts store.

I leave the hood up after every session to remind me to check the level. My S2 engine burns some oil...oddly enough it burned less (based on me refilling it) at the Summit Point July event than previous events.

I killed my first 944 at my first event with it when I used too light a weight and wasn't filled enough.

smlporsche

Well I guess I'm of a different opinion than everyone else...

I'm running 0W-40 M1 instead of 15W-50 like most people.

Most wear occurs when you start the engine cold and a 0W- XX will circulate faster.
Also on a track car with the A/C condensor removed and traveling at a high rate of speed (i.e. good air flow to the oil cooler etc) a 50 weight oil is not necessary and actually requires more effort (i.e. HP) to circulate.

Most pro race teams are using a very low viscosity oil. As an example the propriatary oil that the F1 teams use is something 0W-5...I know you'll say that they also tear their engines down after every race ...but I also think they are much harder on their engines that any of us weekend racers are...

I'm not trying to say that my thinking is the only right answer just what I believe and been using. I do use oil over the course of the weekend but that is independent of what weight the oil is.

93 FireHawk 968

I'm using Joe Gibbs synthetic, 0-30W with a high zinc content, not for vehicles with a catalytic converter. Ideal for oil temps up to 300 degrees. Mobil One's race oil also has the high zince content that their street versions do not.

beentherebaby

BITOG does have a lot of fanbois but the link was in regards to what a UOA can and can't tell you. The fanbois try to use a UOA to tell if one brand or viscosity of oil is better than another. It can't tell you that and it's not intended to tell you that. It's simply a $25 test that tells you if the oil is still serviceable or if it needs to be changed sooner.

An oil test sequence like the auto makers use is the only accurate means to tell how an oil actually performs in the engine. The ACEA A3/B4 oil test sequence is the basis for many Euro car maker oil specs including Porsche's. Each car maker adds the additional family model specific tests that are appropriate for their engines to develop their own oil requirement spec.

http://www.acea.be/images/uploads/pu..._LD_and_HD.pdf

It's important to use an oil that meets the car makers oil requirements for proper chemistry. As noted above I prefer a multi-viscosity oil for street/HPDE events as it flows better cold and provides the desired hot protection. Using the correct viscosity for the ambient temps and engine clearances is important. I'm not a brand fanbois. Any appropriate car maker approved oil of the proper viscosity for the application is good to use.

FWIW, high zinc is mostly of significance for prevention of wear on flat tappet cams. More zinc is not always better as in too much actually causes increased wear according to actual testing. 1% seems to be the magic number.