Sleeper_08

Based on the above I'll also be switching to Mobil 1 10W30 for next season.

Riptide

Who runs a 30W oil? Thats crazy for these cars.

A 30 viscosity oil will shear down as well. I've heard the 20 won't shear as much but I'm not sure if that's true or not.

After reading a bazillion threads about this on Bobistheoilguy I see no reason to run a 30 viscosity oil unless the car is being road raced.

You're gonna be hard pressed to find a single example of a motor failing in these cars from oil.

Sam Strano

Amusing thread...

First of all, none of you are running a 30 weight oil.... you are all running 5's. The second number is a measure of what the oil protects like. The first number is the base weight of the oil. And they don't "thicken" to a 20 or 30... the additive package just protects like those oils. And the more additives you have, the more additives wear out. Rule of thumb is you generally don't want more than 20 pts. between numbers to minimize the additive package. Anyone who's changed warm oil knows it's like water compared to cold oil, certainly not "thicker".

If you want thicker oil, you need to move to a 10/30.

Further, the S197 runs a lot of oil pressure.... that's to help with keep good cushioning in the bearings. I've stayed on 5/20 in the S197's I autocross with no issues for 3 years of tossing, banging off rev-limiters, etc. But I won't run Mobil1 swill, I use Redline.

Yes, I said swill, M1 isn't even a true synthetic (just a highly refined petroleum base-stock Group 3 oil). Redline is a true synthetic Group 5 basestock... And if you don't think that matters, well you don't know much about oil. And fwiw, every engine we've had bearing issues with has been on M1.... In one case in a turbo car 15/50 M1 held half the idle oil pressure as regular old Castrol GTX in (get this) 10/30 weight. There's a clue right there. And the other telling things about M1 are: A customer had a Tahoe that drank oil, did for years--a quart every 1k miles or so. Changed oil (he picked Castrol Syntec randomly), and within the first oil change, it never used another drop again... that my friends is burn-off and something oil shouldn't do especially a "high end synthetic".

You want to talk about it's only a few bucks vs. an engine? I agree. The trouble is M1's marketing is great, and most folks never ever have oiling issues because they don't drive hard enough, which makes anything seem great. I'm not most people and have the above (and a few other) issues with M1. Not to mention it ain't all that cheap relative to really good stuff.

Riptide

AFAIK the only Group 5 synthetics are Redline, Royal Purple, and Amsoil.

I use Pennzoil Platinum right now but the car does seem to go through a bit of oil between changes. It's hard to say why, could just be blow-by. That should be pretty minimal on an NA car especially but I've seen pictures around here of people who pulled the intake and found quite a bit in there.

nemosgt

Oh my! What to do now guys?

Cheers.

nemosgt

Oh my! What to do now?

Cheers.

nemosgt

Sorry about the double post.

Cheers.

zero2sixd

If I were autocrossing exclusively I would stick with 5w20 as well. Runs are typically 60 seconds long. All you should need in that environment is something that flows fast.

To go off on a bit of a tangent here, it seems to me that road courses involve another potential danger vs. autocross which is longer duration high G turns with the potential for oil starvation. Does anybody have any good technical information on that one for the 4.6 3V?

I've seen people advising to overfill the oil by half a quart (or maybe a full quart, can't remember) when doing road course events. On the other hand, I haven't heard of anybody grenading their engine either.

Argonaut

This subject has been discussed ad nauseum on this and every other car forum. It is probably the single most divisive discussion there is when it comes to cars (er...maybe roll cage design is the one, its right up there anyway). I'm not necessarily a M1 fan, and don't really think M1 vs brand X is the question here but rather what weight to use. But I will say this - I've run the Mustang very, very hard with M1. I've had that oil tested by a lab several times and it passed with flying colors. So whether or not it's "the best" I don't give a rats a**, its good enough for what I do and its readily available. So is Castrol, Valvoline, etc and I'd be just as willing to use those. Regarding weight - I've seen lab reports of 5W20 used in a track car that didn't look so hot. It could have been the oil...it could have been the car. But given the data I've seen and the opinion of S. Whitehead (the Ford engineer referenced above) I won't use 5W20 on the track. On the street, absolutely, but not on the track. I would use 10/30 though.

And one more thing - in my LS1 I've used the Amsoil racing oil and the lab report wasn't so good. I'm a little disappointed in it to tell you the truth. But, its hard to draw conclusions on one oil test. I really need more data before I can determine if Amsoil is going to really serve me better or just take more money out of my pocket.

Now - go forth and believe what you want because just like the proverbial A-hole, everybody has an opinion on which oil to use and most of them don't agree.

Argonaut

I don't have any data specifically on the mod motor but I follow a lot of road racing news and forums and haven't really seen any info about guys blowing their engines due to high G turns. I have seen discussions about the rear main bearing going out, but thats not due to G loading. Now the Chevy LSx motors its a different story. The LS3 is ticking time bomb on the track in high G left hand corners do to oil pooling in the heads and starving the mains. All C5 and C6 Corvettes have oiling problems and yes the recommendation is to run them a quart over. I think their biggest problem is they have such a shallow oil pan, the Mustang is far deeper by comparison.