Gearheads and oil analysis. Yes oil!!!


nautoncall

GT Owner
Mark II Lifetime
Apr 6, 2014
1,036
So there are always topics on whats the best oil to use and I've spend countless hours reading forums on what oil to use on my cars. Still confused as ever but I thought I would post a different type oil thread and get everyone's analysis on some of my oil analysis on my cars. I have come to the conclusion that manufacture's guides are just that....guides. Below are oil analysis from several different cars. I send my oil after every change which I do myself. I'll make some observation after the posting. I'd love to hear some of you gearheads ideas and thoughts.
 

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nautoncall

GT Owner
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Apr 6, 2014
1,036
Last one.
 

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nautoncall

GT Owner
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Apr 6, 2014
1,036
1. The Blue GT seems to be doing fine with the Motorcraft 5/50 and yes not many miles on last sample but it was over a year and the flashpoint was borderline. Overall acceptable.
2. The Twin Turbo Red GT seems to sheer the oil much more. The flashpoint is always way down on the samples. Much less than I would like. This car was used with race fuel for a while and none has been run in it for at least 2-3 years so the lead is washing out dramatically. I run exclusively 93 octane and have done no drag races or any such events..just some fun street runs but nothing excessive. All changes have been Motorcraft 5w-50. Based on my analysis, I now filled with Redline 5w-50 and will report back on the next oil change.
3. The 65 Cobra is a race motor with 675hp and 625 ft/lb that I was told to run on Mobil 1 5w-20 but I recently called the engine builder and they said I should be running VR1 10w-30. It's a dino oil also. I have changed to that and can report back at next change. I think the flashpoint will improve plus the small fuel dilution probably has contributed but the VR1 should fix this.
4. 92 Viper with excellent first change on Rotella T6
5. Diablo first change was Agip 10-40, second was Rotella T6, and last was Agip 10-40. Seems like the Rotella was a little better. I didn't like the viscosity and flash points on the last change. Agip is syn blend.
6. The TT 04 Viper seems to be doing great on VR1 20w-50. This is the most confused vehicle I have because everything I read says this is too heavy. I have two different Viper turbo shops that's main business is TT Vipers and they say to run the regular conventional VR1 20w-50 that I"m running. This is why I have exclusively used that oil. They make a synthetic but these two shops say use the dino oil. I've yet to get a real good reason. Some TT viper guys run M1 15w-50 and swear buy it also. Stock viper suggestion is 0w-40. I have been temped to run T6 in this car but not sure.
 

nautoncall

GT Owner
Mark II Lifetime
Apr 6, 2014
1,036
Any FGT owners want to share any of oil analysis on either Motorcraft or their oil de jour? Thoughts on shear in turbos??
 

MTV8

GT Owner
Mark II Lifetime
Jul 24, 2010
916
Houston Texas
No turbos on my GT, but I can tell you that Underground Racing also recommends VR1 20w50 for my twin turbo Lamborghini with built engine. They specifically say to use the conventional version and not synthetic.
 

nautoncall

GT Owner
Mark II Lifetime
Apr 6, 2014
1,036
No turbos on my GT, but I can tell you that Underground Racing also recommends VR1 20w50 for my twin turbo Lamborghini with built engine. They specifically say to use the conventional version and not synthetic.
Well if you can get someone to tell you the reason I’d like to know. I still can’t get a straight answer on “why” the Dino VR1!!! Turbo shop that built the car said to go 10k miles on the conventional since the motor was just built. Then syn was ok!! Then I read on multiple places where a few hundred miles are fine!! Thanks for chiming in!! I’ve spent hours on BITOG!!! Still confused!!
 

HighHP

GT Owner
Jun 3, 2019
237
Spokane, WA
Well if you can get someone to tell you the reason I’d like to know. I still can’t get a straight answer on “why” the Dino VR1!!! Turbo shop that built the car said to go 10k miles on the conventional since the motor was just built. Then syn was ok!!
Here is a common held theory why, which all builders may not support.
Begin with what is happening in a new engine. The cylinders are purposely honed to a rough surface that actually cuts the rings, which provide a perfect fit of the rings to the cylinders. The rings need to be cut before the cylinders lose their roughness and smooth out. It is thought that short bursts of hard acceleration help this cut-in process. The high pressure gasses in the cylinder actually fill the space on top of and behind the ring pushing it tight against the cylinder. This cutting process creates heat and fine metal filings, so hard acceleration should be short in duration. Followed by light load allowing the oil to cool the rings and clean out the fine metal filings. So short durations of high load followed by normal driving. This should be done in the first few miles of driving or running the engine on a test stand. A rebuilt engine continues to break-in for 10,000 miles. HP gains are commonly noticed during this 10,000 mile break-in period. Thus, I think this is why the builder above noted 10,000 miles. I think car manufacturers just say to drive the car like normal for break in without sustained high load.

I began building custom engines at a young age back in the 1970's. Back then everyone ran non-detergent or mineral oil for break-in oil for the first 500-1000 miles. Supposedly, it was critical for piston ring break-in. It was thought that detergent additives negatively affected this cut-in process.

Then enter the high quality synthetics. Synthetics are considered more slippery than conventional oils. This slipperyness, it is thought, does not allow the rough cylinders to cut the rings. The lubrication is too good. The rings smooth out the cylinders before the cylinders have time to cut the rings. So the rings never seat properly in the cylinders. Not sure what ever happened to running mineral oil for break-in, but now builders recommend conventional oil during break-in and not to use synthetics. I do not know for sure what the OEM manufacturers put in their engines for break-in, even when they spec synthetic when replaced. So now you have it.
 
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nautoncall

GT Owner
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Apr 6, 2014
1,036
HighHP...thanks for the great explanation! I’ll keep running conventional for now!!!
 

Gene Cassone

GT Owner
Mark II Lifetime
Dec 3, 2005
831
way upstate NY
Interesting! I had a new M3 years ago that came with mineral oil, then at 900 miles was changed to synthetic.
 

33Bravo

GT Owner
Mark II Lifetime
Nov 3, 2006
686
Minneapolis, MN
Rebuilt aircraft engines are always broken in with mineral oil....
 

HighHP

GT Owner
Jun 3, 2019
237
Spokane, WA
Yep. Aircraft pistons also run mineral oil with dispersants after break in. They don't use detergents like auto oils. There is a safety story on why no detergents.
Shell oil info for aircraft recip's.

AeroShell Oils 65*, 80, 100 and 120

AeroShell (straight mineral) Oils are available in four different viscosity grades (SAE 30, 40, 50 and 60). They are blended from selected high viscosity index base stocks and contain a minimum quantity of additives. These oils are especially appropriate during the break-in period of most new or recently overhauled four-stroke aircraft piston engines.
 

nautoncall

GT Owner
Mark II Lifetime
Apr 6, 2014
1,036
New automotive engines are so precisely made I think synthetic is ok from the start
 

twobjshelbys

GT Owner
Jul 26, 2010
5,374
Las Vegas, NV
My recollection on my Cobra Roush 427 was that they recommended using a regular 10/30 for the first part (1000 miles?) and then a synthetic was OK. The block is a modern machining (Pond or Dart, not sure which) so has the tolerances of the modern engine. Mine used almost no oil.
 
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