Changing the oil


Beach-GT

GT Owner
Mark II Lifetime
May 8, 2006
883
Seminole Florida
The only thing stopping me from using it is the 5W-40 rating vs 5W-50 for the Motorcraft oil. I just add the ZDDP additive that you can also get on Amazon. I am hoping that brings the new oil up to the old oil specs. Since it is hot most of the time in Florida the 50 rating makes me feel better.
 

jcthorne

GT Owner
Aug 30, 2011
792
Houston
The 5W50 motorcraft is THINNER than the 5W40 Rotella in less than 1000 miles. Its down to a 30wt by 2000. This is why many of us will not use the newer Motorcraft. Its only a 5W50 when new in the bottle, not in use. Of course if you don't drive the car, it does not matter much.

RedLine makes a great real 5W50 that does not break down, turns out its too thick for the DOHC motors.
 
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MNJason

GT Owner
May 14, 2010
2,016
Twin Cities
I too switched to Rotella after poor results with the Moto. Much better results with the T6 and I'll be sticking with it.
 

PeteK

GT Owner
Apr 18, 2014
1,210
Great Falls, VA
Does anyone know why Ford specifies 5W-50 viscosity? If the 5W spec is for winter use, and those who don't drive (or more importantly, start up) in really cold temps, we could substitute 15W-50, which is commonly available and much less $$. On the high end of the viscosity spec, the highest lubrication stress in the engine is the cam/follower interface (this is the primary need for ZDDP in conventional oils). But the cams in GT engines are not aggressive profiles (don't need to be with forced induction to get more air into the engine), and equivalent engines in the F-series trucks don't specify that high of viscosity. Furthermore, the Ford "modular engines" use roller followers, which greatly reduce the stress on the cam/follower interface (including our GT engines). In fact, Ford specifies 5W-20 for most engines produced since the early 2000's, including the other 5.4's, and 5W-30 for the Ecoboost engines. Why 50 for the GT engine?

Any experts here have insight into Ford's reasoning? Was it just overkill since they didn't have time for a full test/development cycle? TIA
 

jcthorne

GT Owner
Aug 30, 2011
792
Houston
All of the supercharged modulars have specified the higher viscosity for the high bearing loads on the main bearings. Especially the front bearing driving the SC.

The 5W cold viscosity is to prevent over tensioning of the cam drive chains at start up and drive off. This was a real problem for the early modulars in the early 90s. Many failed front cam bearings from using the wrong oil with too high initial viscosity at start up. And not just at very cold temps.
 
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MAD IN NC

Proud Owner/ BOD blah bla
Mark IV Lifetime
Feb 14, 2006
4,188
North Carolina
This new Amsoil product seems to meet the WSS-M2C931-C spec for FGT, Mustang, etc:

http://www.amsoil.com/shop/by-equip...ature-series-100-percent-synthetic-motor-oil/

APPLICATIONS
AMSOIL Signature Series Synthetic Motor Oil is excellent for use in all types of gasoline-fueled vehicles. It is recommended for all domestic and foreign vehicles requiring any of the listed performance specifications:

5W-50 (AMR): API SN, SM...; Ford WSS-M2C931-C (Mustang)
I was waiting for Amsoil to step up..... took them long enough.

Q: Does anybody know what is the spec difference between the "A" 5w50 that was first produced for the FGT versus what FoMoCo sells today as 5w50 known as the "C" spec'd? Then, will the Amsoil fit the bill of the "A" spec?

I'm hoping IndyGt the answer man should know...
 
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Beach-GT

GT Owner
Mark II Lifetime
May 8, 2006
883
Seminole Florida
I don't even get a 1000 miles on an oil change in the GT. I move it to the Lexus and finish it off.
 

BlackICE

GT Owner
Nov 2, 2005
1,413
SF Bay Area in California
I don't even get a 1000 miles on an oil change in the GT. I move it to the Lexus and finish it off.
EP never reached 1000 miles on any of his cars.
 

bonehead

GT Owner
Mark II Lifetime
Aug 18, 2012
2,777
Houston, TX
I don't think I've seen the Joe Gibbs product mentioned anywhere. Does anyone have experience with this?

04106.jpg

http://www.drivenracingoil.com/dro/fr50-5w-50-synthetichtml/
 

Kingman

GT Owner
Mark II Lifetime
Aug 11, 2006
4,071
Surf City, USA
Doesn't Gibbs Racing use Toyota's? :biggrin
 

Indy GT

Yea, I got one...too
Mark IV Lifetime
Jan 14, 2006
2,435
Greenwood, IN
Does anyone know why Ford specifies 5W-50 viscosity. Any experts here have insight into Ford's reasoning? Was it just overkill since they didn't have time for a full test/development cycle? TIA
Pete,

Not an expert here but have talked to a number of engineer’s on the engine team. I believe jcthorne adequately answered your oil question on the high and low end viscosity ranges Ford selected for our GT engines.

And I take issue with your assumption Ford “didn’t have time for a full test/development cycle”. Even though the development time for the FGT was abbreviated (tremendously) the engine team really did do a full design/development cycle on our unique 5.4L dry sump engine. Surely it shares features with the other 5.4 modular family but the engine design is unique to the FGT. See SAE publication 2004-01-1252 for some of the technical details that Ford could make public. I am certain there were proprietary details as well.

Ford introduced the Motorcraft Full Synthetic 5W-50 oil (WSS-M2C931-A, black cap) specifically “designed, engineered and recommended for use in the Ford GT”. It was developed as a singular target oil for the GT. The oil development (which I believe was originally sourced from Conoco-Phillips) paralleled the engine development and all the OE durability, hot/cold testing was done with this oil.

In speaking with some of the team members after the WSS-M2C931-B (gold cap) version came out which removed the ZDDP additive due to EPA instance for catalyst fouling, the GT team was caught off guard. They did not know the ZDDP-less oil had been released and how the removal of this additive might impact any warranty issues. I am told that to Ford’s credit they pulled a line engine and reran the whole engine durability test cycle on the new –B oil just to make sure there were no issues which might pop up without the ZDDP additive in the oil. The engine successfully passed this test.

Q: Does anybody know what is the spec difference between the "A" 5w50 that was first produced for the FGT versus what FoMoCo sells today as 5w50 known as the "C" spec'd? Then, will the Amsoil fit the bill of the "A" spec?
I'm hoping IndyGt the answer man should know...
Hi Mad.:biggrin
I still have a few cases of the Motorcraft Oil in my basement since both the Boss and GT use the same oil. My cases are all the –B version of the WSS spec. I did not know that Ford (or their supplier) had rolled to a third –C level for the oil. Will be traveling up to Detroit shortly and I will see if I can learn what caused the oil spec to be revised yet again. Does the -C spec oil have yet another color cap?
 

bonehead

GT Owner
Mark II Lifetime
Aug 18, 2012
2,777
Houston, TX
Doesn't Gibbs Racing use Toyota's? :biggrin
Yeah, I guess they do. lol
But this stuff says specifically engineered for Ford Coyote and supercharged applications.
 

Kingman

GT Owner
Mark II Lifetime
Aug 11, 2006
4,071
Surf City, USA
Interesting....!

We've got guys here that know more about oil than I thought humanly possible. I wouldn't be surprised if they run a thorough analysis and report back before the day is out.
 

Xcentric

GT Owner
Mark II Lifetime
Jul 9, 2012
5,216
Myakka City, Florida
As Indy GT might say, "The search engine is your friend."

jcthorne's treatise on Rotella T6 convinced me of its superiority to the reformulated Motorcraft oil.

And you can buy it in gallons cheap on Amazon.
 

BlackICE

GT Owner
Nov 2, 2005
1,413
SF Bay Area in California
If you can safely start the car in 0 degree with 5w then wouldn't using a 10w or 15w be no worse in 70F?
 

blkdiablo33

Well-known member
Nov 27, 2006
56
los angeles
great info.this is why thses forums are so important
 

Indy GT

Yea, I got one...too
Mark IV Lifetime
Jan 14, 2006
2,435
Greenwood, IN
Prime Procedure

What Mike points out above regarding dry sump engine priming after an oil change is absolutely correct. However, the listed steps MUST be FOLLOWED EXACTLY as he lists. Do each step in listed order....!
  1. Turn the key to the on positiion.
  2. Hold the accelerator pedal on the floor.
  3. Push the start button.
  4. Let it crank until you see oil pressure via the gauge in the dash.

Upon seeing pressure, let up on the start button, BEFORE you let up on the gas pedal.

Release the pedal and then start normally.
 

MAD IN NC

Proud Owner/ BOD blah bla
Mark IV Lifetime
Feb 14, 2006
4,188
North Carolina
DON'T FORGET the PRIMING OF THE OIL SYSTEM!

from a nota4re post in another thread.....


PRIMING INSTRUCTION AFTER OIL CHANGE:
"After re-filling, and as a dry-sump system, it should be primed BEFORE starting the car. (I'll bet this step is skipped a lot.) You need to turn the key all the way to the "on" position, hold the accelerator to the floor, and crank the engine for a full 20 seconds. The car will not start as long as the pedal is floored. watch you Oil pressure gauge while doing this. You will see that it takes 10-15 seconds of cranking before the first sign of oil pressure."

Once you see oil pressure, stop cranking reset key and start car normally....
 

Empty Pockets

ex-GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Oct 18, 2006
1,291
Washington State
Thanks....I guess i will re change my oil. So i actually only drained the oil sitting in the oil pan? Now at least i know the oil fill tank holds the additional 1.5 quarts.

Now for a question? How can an oil fill canister also double as a dry Sump.

What is the difference between a dry sump & wet sump?

i will sit back & listen.

In a nutshell, a wet sump system is the std system used in most cars. The oil is contained in the oil pan directly under the engine & the oil pump pickup sits at the bottom of it (the pump itself is bolted to the bottom of the block). The 'pump pulls oil from the pan and gravity drains the oil back to the pan.

A dry sump system uses an external 'pump and oil tank. The dry sump pump has a pressure section and scavenge sections. The pressure section of each feeds oil to the block, while the scavenge sections pull oil from special pickups in the dry sump oil pan and return the oil to the external storage tank.
 

texas mongrel

GT Owner
Mark II Lifetime
May 3, 2009
1,453
Houston Texas
I just finished my first oil change yesterday. This FAQ link was a big help, especially the part about priming the pump before firing her up after the change.
Some comments: firstly, there are way more than the 19+21 screws mentioned elssewhere in this thread - we counted 60 altogether. Next, I did my change at a buddy's shop, and we found that backing the car onto his alignment pit gave fantstic access to everything. This really made it so easy. Lastly, we found a cat collar inside of the undertray, complete with a little tinkle bell! I had a vision of a chewed-up kitty going round and round in the engine pullies, but my wife pointed out that it had probably somehow got stuck and simply pulled off the collar to free itseslf - a more likely scenario, but a less vivd image! So, if any previous owner of 2006 blue #1853 wants his pet's collar back, let me know. Also, if there's anyone in Houston looking for an easy oil change, let me know and I'll hook you up with Henrik who let me use his shop. Thanks to all previous posters on this thread for providing good background info.
 

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