Highly Modified 03 Cobra. What oil to use?!

[DannyB]

Well...Ive done my due diligence, as much as possible. Searched, called, and searched some more. So now Im asking the experts.

Being new to "understanding oil" the way most of you do, I just need a little push in the right direction.

I have read sooo many threads of: "modular motors have to tight a tolerances to take anything over 5w20" to, "I personally run a 40 weight oil and its fine."

I know Ford recommends 5w20, but the ausie versions are specked with 5w30. Pretty sure this was just for CAFE reasons.

Regardless, here is the info on my car, what is currently in it, and what Im thinking of running from the info I could find?...

2003 Ford Cobra
5.1 Stroker
2.8 Kenne Bell
36k on car
Approx. 10k miles on motor
Makes 630hp on low boost/pump gas. Conservative tune.
I do "baby" the car, but enjoy the spirited driving every so often....how can you not with that power on tap?

CURRENTLY has 15w40 Rotella T. (Recommended by unknown shop. Was told this by previous owner. Motor was not built by me)

Now, I live in Oklahoma and the temps are pretty warm. Car wont get driven alot when the temps are in the 20-40* range.
On Start-up in the mornings it idles at 90-100 lbs of pressure. Maybe I'm old-school, but that seems HIGH. When fully warmed it idles at ~40. Cruising speed ~60lbs.

I dont know the additives package in the M1 0w40 (couldnt find it), but that is what I was leaning towards, simply based of some others in the same mod/hp range running the same.


Really looking for some good technical info as to whats better for my application, rather then "well this is what I run, and its great". But, If you have a similar car/mods, please do share what you run!

Thanks in advance!!

I have readily available access to (amsoil, RP, and most brands carried by typical part stores)

 

[Smokefan1977]

redline 5-30

 

[addyguy]

Redline 5W-30. It's made for high-performance applications, like this.

 

[OVERKILL]

Redline or M1 0w40.

 

[DannyB]

Originally Posted By: OVERK1LL
Redline or M1 0w40.

Thanks! Have read some of your posts. Glad you chimed in!

 

[DannyB]

Am I correct in assuming that there are not variants of M1 0w40, and that it is all their "Euro Formula"?

 

[OVERKILL]

You are very welcome. The M1 is much more readily available. I have a buddy who owns a tuning shop in Florida. He had an '03 Termi that made 850 to the tires with a pair of twins on it back when he lived up here in the GWN and ran M1 5w30 in it IIRC.

M1 0w40 is a highly decorated oil; it has a huge list of factory approvals and high HP apps that it is the oil of choice for. I'll be using it in the M5 on its first OCI.

 

[OVERKILL]

Originally Posted By: DannyB
Am I correct in assuming that there are not variants of M1 0w40, and that it is all their "Euro Formula"?


Correct. It is a Euro-spec oil.

 

[DannyB]

Fantastic!!

Good to know!

 

[ARCOgraphite]

What oil temps are you seeing when you drive it "hard"? The current 15w-40 rotella is probably leaving lots of power at the table - LOTS. A good 10w-40 motorbike oil would be better than any ILSAC GF4/5/ rated oil. I would call redline and ask them**, but common sense would dictate that a 30 grade Ester/AN/PAO highly additised with a great HTHS should be adequate.

**This is a community forum with "anybody" giving advice.

 

[SteveSRT8]

We run Amsoil Dominator in a huge big block blower motor in a go-fast boat.

It has a great reputation and is really the "good stuff" for a real racing engine.

Unless that engine is really set up loose I can't see why you need such thick oil.

 

[chubbs1]

M1 0w40, is great, Amsoil and RP 5w30's are great. RedLine is definitely a more shear stable oil designed for harsh use but it is pricey and I don't think you need it by the way you describe driving habits.

My personal choice would be M1 EP 5w30. Outstanding oil and usually on sale with a M1 filter for $35. You can't beat that. I would do a UOA to see how any oil you try is holding up.

 

[440Magnum]

Do you know your actual oil pressures and maybe even oil temperatures? That would help decide if a 5w20 or 5w30 is enough.

Given that you're boosted and capable of pushing big numbers, I'd err on the side of a little heavy and run something like others have recommended- Redline's 5w30 or M1 0w40 (one is a "thick" 30, the other a "thin" 40), both very solid lubricants.

Looking at ACTUAL oil pressures on these modern engines that are spec'd for 20-weight oils can be revealing. They really are set up to be OK with thin oil- they move a lot of oil with the oil pump and can generate seriously high pressures. Being a Mopar-head, my reference for that type of engine is the Dodge 4.7. My own will develop 80 PSI at 3500 RPM on a 100-degree day after being run for an hour on the highway, and will easily run 60 PSI at cruise in overdrive (~1900 RPM) under the same conditions. The timing chains are actively tensioned by oil pressure (with a mechanical "ratchet" backup so they won't jump on startup), so running a significantly thicker oil would just grind the chains harder against the guides and increase wear. It might be worth it for a dragstrip truck if I were running boost and needed the added shock protection for the main bearings, but for normal driving (and that includes towing up to a 14,000 lb GCVW) 20-wt should be fine. The Modular might be bit different ahdn have fewer issues with higher pressures developed by thicker oil.

 

[A_Harman]

Redline 5w30 and M1 0w40 have the same HTHS viscosity to start with.
Redline will be more shear-stable than M1 over time.
It also contains more anti-wear and oxidation inhibitors.
So it costs $9-10 per quart. Look at it as cheap insurance to protect your $10,000 engine.

 

[Smokefan1977]

As you can see in my sig i use both and couldn't be more happy. Both spec at a 3.8. Redline is a heavy 30wt and 0-40 is a light 40wt

 

[OVERKILL]

Originally Posted By: A_Harman
Redline 5w30 and M1 0w40 have the same HTHS viscosity to start with.
Redline will be more shear-stable than M1 over time.
It also contains more anti-wear and oxidation inhibitors.
So it costs $9-10 per quart. Look at it as cheap insurance to protect your $10,000 engine.


How much is a Porsche or Mercedes engine worth that is factory protected with M1 0w40?

 

[aquariuscsm]

I`d say a good gasoline 40 weight. Royal Purple 10W40 or Mobil 1 10W40HM (for the better add pack). Reason I`d use a gasoline oil over an HDEO (diesel/gas rated) is that I`ve read here and on some other forums that HDEO`s *can* be abrasive. Any hard evidence on this?

 

[DannyB]

Originally Posted By: ARCOgraphite
What oil temps are you seeing when you drive it "hard"? The current 15w-40 rotella is probably leaving lots of power at the table - LOTS. A good 10w-40 motorbike oil would be better than any ILSAC GF4/5/ rated oil. I would call redline and ask them**, but common sense would dictate that a 30 grade Ester/AN/PAO highly additised with a great HTHS should be adequate.

**This is a community forum with "anybody" giving advice.

I do not know, as I dont have a temp gauge. Have ajust about everything else tho. I just purchased the car, so that is a 'near-future' addition.

As far as the 15w40 being in there, I have read a few things that the timing chain tensioners like/need the 5w20/5w30. If this is true, could leaving the 15w40 cause problems?

 

[DannyB]

for what its worth, Im very impressed with the rate, and quality of the responses here. So a big thanks to ALL that have patience for those who know less then yourselves.

 

[TFB1]

I use the M1 0W-40 in my supercharged Marauder, been great so far...