Approved oil no longer available from Mobile one or Castrol?


RALPHIE

GT Owner
Mar 1, 2007
7,279
Bill -

In the past (before the replacement engine), I have used an aftermarket "lead substitute" gasoline additive in my '66 Mustang to decrease the valve friction due to the unhardened valve seats.

Similarly, for an increased level of Zinc, it is possible to add some Comp Cams Break-In Oil Additive 159-12. However, the detriment would likely be to Catalytic Converters on the cars (mine has not CATS).

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Just a thought for those who are concerned about the reduced level of ZDDP in the Motorcraft XO-5W50-QGT.
 

gtinmyblood

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Feb 23, 2007
735
Mesa Az/Aspen Co
It seems that some months ago there was a change in the formulation of the Mobil One Synthetic that I had previously used for oil changes and it is no longer approved by Ford. What has changed? What oil is good to use in the FGT these days?

Anyone have knowledge of this?
 

FENZO

GT Owner
Mark II Lifetime
Jul 7, 2008
1,516
Lafayette, CO
Oh man.. you had better duck. The "search is your friend" mob are lighting their torches. :biggrin

http://www.fordgtforum.com/forums/s...5W-50-full-synthetic/page10?highlight=rotella

I can't answer about Mobile 1 or Castrol, but I think a lot of folks use OE or Rotella.

frankenstein-angry-mob_10.jpg
 
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PeteK

GT Owner
Apr 18, 2014
1,342
Kalama, WA
I would not worry about ZDDP levels in motor oil for our cars. ZDDP is really needed in engines that use old-style tappets or lifters, in which the cam lobe wipes across the lifter face as it turns and raises the valve train. That cam/lifter interface was the highest pressure point in the engine, and it needed ZDDP, which "plates out" on the surfaces to protect them in extreme pressures. With roller followers, it is much lower, and the motion is a rolling motion, not a wiping or scuffing motion. So, high ZDDP isn't really necessary anymore.

Yes, the FGT engine has roller followers. See p. 303.01.30 of the workshop manual.
 

jcthorne

GT Owner
Aug 30, 2011
792
Houston
Rotella T6 5W40 full synthetic.
 

twobjshelbys

GT Owner
Jul 26, 2010
5,374
Las Vegas, NV
There is an Amsoil product too:

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

I mentioned it in the oil thread here, there may be more discussion after this post:

http://www.fordgtforum.com/forums/s...anging-the-oil?p=386118&viewfull=1#post386118
 

bonehead

GT Owner
Mark II Lifetime
Aug 18, 2012
2,777
Houston, TX
I'm still using Motorcraft 5W-50.
 

zach05855

GT Owner
Oct 16, 2012
211
Calgary, Alberta
someone is fearless in asking that question. You better be prepared.
 

Indy GT

Yea, I got one...too
Mark IV Lifetime
Jan 14, 2006
2,435
Greenwood, IN
someone is fearless in asking that question. You better be prepared.
Zach has been a member of our Forum since October 2012 and he obviously knows the score.

What oil is good to use in the FGT these days?
Gtinmyblood has been a Forum member since February 2007. 2007 , as in eight years.

Sorry for my comment, but can you reasonably really ask this question?:facepalm:
 

gtinmyblood

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Feb 23, 2007
735
Mesa Az/Aspen Co
Sorry to raise an s*%t storm by asking the question. Tried the searches but they weren't working for me. I appreciate you guys kicking in. Had my own supply till now so for me its a recent issue.

Thank you for the direction.

As for the comment on how long I've been here and "reasonably" asking the question...No offense taken. Lately life has had me so busy that I haven't had near as much time as I would like to browse this fantastic site.
 

Kingman

GT Owner
Mark II Lifetime
Aug 11, 2006
4,072
Surf City, USA
Rotella T6 5W40 full synthetic.
+1 based on Forum discussion.

Just took delivery from Amazon (signed up for Prime and now enjoy free 2-day shipping).
 

MAD IN NC

Proud Owner/ BOD blah bla
Mark IV Lifetime
Feb 14, 2006
4,198
North Carolina
Herb,, I've been converted to Rotella baby.... no viiscosity breakdown. Lasts long time. All good. 2+ now
 

zach05855

GT Owner
Oct 16, 2012
211
Calgary, Alberta
I also use Rotella T6
 

Indy GT

Yea, I got one...too
Mark IV Lifetime
Jan 14, 2006
2,435
Greenwood, IN
As for the comment on how long I've been here and "reasonably" asking the question...No offense taken. Lately life has had me so busy that I haven't had near as much time as I would like to browse this fantastic site.
Gtinmyblood, thanks for being a good sport about my comment. I thought about it last evening and hoped I did not offend your honest question. I was not going to be surprised to see Dave booted my post as we all try to be respectful of each other. Glad you are back on our Forum! It is a great place to hang out.:thumbsup

Oil topics take on a life of their own, and many owners have passionate opinions.

I take the no-brainer approach and use the Ford recommended Motorcraft 5W-50 oil. I change it frequently enough to not be concerned about some reported viscosity breakdown.
 

Sinovac

GT Owner
Mark II Lifetime
Jul 18, 2006
5,691
Largo, Florida
Another vote for Rotella T6 5w-40. I use it in everything except air cooled V-twins.
 

BlackICE

GT Owner
Nov 2, 2005
1,415
SF Bay Area in California
I take the no-brainer approach and use the Ford recommended Motorcraft 5W-50 oil. I change it frequently enough to not be concerned about some reported viscosity breakdown.
Yes, but should you be concerned if you followed Ford's recommend change interval with Motorcraft 5w-50?
 

jcthorne

GT Owner
Aug 30, 2011
792
Houston
Also realize that the recommended Motorcraft full synthetic for the GT is no longer sold. The oil now sold as a replacement is not the same.
 

Indy GT

Yea, I got one...too
Mark IV Lifetime
Jan 14, 2006
2,435
Greenwood, IN
Well ICE, this hypothetical could be extended to a number of different issues.

Like, should I be concerned that the sun would not come up in the morning, or should I be concerned that an airplane will fall from the sky onto me as I cut my grass?

You certainly could worry about those things. (And I do consult the Farmer’s almanac and wear a hat while I cut my grass to be proactive):lol

I do not have my FGT owner’s manual handy at the moment but am sure I change my engine oil much more frequently (time and mileage) than the owner’s manual recommends. I would venture a guess that most of our FGT owners do so as well. Ralphie and Jeff chime in with your experience. If the multi viscosity polymers added to the oil giving the virgin oil its 5W-50 range do as some have suggested break down and the viscosity homogenizes to say a straight 30 or 35 weight oil, for the duty cycle and ambient temperatures to which I run my engine, my personal belief is the oil viscosity is acceptable. And knowing the continued product over-checking performed by Ford on this oil and the durability testing the engine went through for production release using this oil, I am perfectly happy just using what Ford recommends for this as well as my other Ford high performance engines.

As stated, this is just my opinion. Engine oil selection is a polarizing topic and other owners are certainly free to make their own oil choice based on their experience/beliefs.
 

Xcentric

GT Owner
Mark II Lifetime
Jul 9, 2012
5,213
Myakka City, Florida
^^^I agree 100% with Bill. I use Rotella T6 because it's cheaper. Just like I use Bridgestones because they're cheaper than Goodyears. Just like I got a vasectomy in my 20s because it was cheaper than a lifetime of condoms.

You know, none of this stuff is worth stressing over. Except unwanted pregnancy.

P.S. I never heard that Mobil 1 or Castrol were acceptable. :confused
 

RALPHIE

GT Owner
Mar 1, 2007
7,279
I'll chime in, Indy - but I really can't say that I'm very good at keeping the oil change intervals low. When traveling across the country (almost every year now), it's difficult to accomplish. However, I don't feel that one has to be strict when one drives 8-10 hours/day for 4-5 days in a row. Normally, I change the oil myself - and on the road, I have Rich & Denis do it for me (I've even detoured ~200 miles to get up to the GT Guy for a change before heading home). I always have used the Motorcraft oils in both the engine and transaxle, and like to fill up with Chevron Supreme at least every 5 fill-ups or so, as I'm told that the Techron additive is good for our injectors.

For those interested, here are my intervals -

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