Bentley GTC OEM, GC at 3,000mi & 6,000 mi

[AEHaas]

This is a Bentley GTC UOA at 1, 2 and 3,000 miles taken from the OEM oil. The first factory scheduled oil change was at 10,000 miles. My plan was to run a UOA every 1,000 miles for as long as I can stand not changing the oil or to 6,000 miles, whichever occurs first. No oil was added.

After the 3,000 mile UAO, at about 1 year of the cars life, I changed the oil to 0W-30 Castrol GC. I ran the GC for 3,000 miles now and decided to test the oil twice, cold and then hot after driving for 30 minutes around town. The car was sitting for 4 or 5 days before the cold sample was obtained. We then drove the car. We came home and drew another sample hot.

The engine is a 6.0 liter twin turbo W-12 with 550 BHP, compression ratio 9:1, top speed - 198 MPH and 0 - 60 dash = 4.8 seconds. The curb wt. is 5,500 lbs., EPA 11, 24 MPG.

....................OEM Oil - - - - - - - - - -> - - - - New Castrol GC - -
Miles on car...1,000 mi.....2,000.....3,000.....6,000 cold...6,020 hot
Miles on oil....1,000.........2,000.....3,000..........3,000+/-.........
Iron___________22_______23_______33_______15____15
Chromium _____ Nickel _________1________2________2________1____ Aluminum ______5 _______7________6________4_____2
lead __________ 1________1________3________1_____2
Copper ________32_______34_______41_______7_____7
Tin ____________5_______3________3________1____ Silver ________ Titanium _______ Silicon ________ 37_______34_______39_______9_____9
Boron ________228______195_______219______17____16
Sodium _______ 15_______12________13______5_____5
Potassium _____ Molybdenum ____91______81________92_______7_____7
Phosphorus ____1027_____936______1035_____865___877
Zinc _________ 1151_____1027_____1182____1000___1026
Calcium ______ 3228_____2915_____3301____1780___1857
Barium _______ Magnesium ____22________21_______29______455____485
Antimony _____ Vanadium _____ Fuel %Vol _____1.5______ Wtr %vol ______ Vis CS 100C __ 12.3______12.1______12.1____10.9___11.1
SAE Grade ____30________30_______30_______30____30
Gly test ______Neg_______Neg______Neg_____NEG___NEG
TBN ________not done____NA_______NA______NA____NA
Abs Oxid______23_______27________29______14_____12
Abs Nitr_______10________13_______14______12____12
Fuel soot______NA________NA_______0.0_____NA____NA

Test lab was: youroil.net

aehaas

 

[Steve S]

The hot and cold tests are most interestng. Thanks

 

[addyguy]

Wear came down nicely, but your 'run' doesn't sem to have burnt much of the fuel out of the oil.

I'm sure 3% fuel is nothing from a twin-turbo, 6-liter V-12. That is one big, powerful engine!

 

[Jaymus]

Awesome car. Awesome UOA. Always wondered the difference between a cold and hot UOA. I have been anticipating this thread. Are you going to stick with the GC for another UOA?

 

[AEHaas]

I will probably go another 1,000 miles then change the oil. I still have some GC to use up and it will be a year on this oil by then.

aehaas

 

[Bill in Utah]

3k miles in a year....

How would it be? (as his 3.5 year old car just passed 130k)

Take care, Bill

 

[SubLGT]

AEHaas, when you sampled at 1000, 2000, and 3000 miles, was this after a 20 mile drive? Why do you think your fuel is now up to 3% ?

 

[AEHaas]

"Why do you think your fuel is now up to 3% ? "

The last few trips were all less than 1 - 3 miles, the store, out to eat next door and to friends homes within the neighborhood. Half a dozen short trips from a cold start = fuel dilution. I tried to get my wife to drive an hour to Tampa and an hour back this weekend. I was then planning to get another UOA to see what happened to the fuel dilution. But the wife was not in a travel mood.

aehaas

 

[jaj]

Originally Posted By: AEHaas
I tried to get my wife to drive an hour to Tampa and an hour back this weekend. I was then planning to get another UOA to see what happened to the fuel dilution. But the wife was not in a travel mood.

aehaas


Did you offer to go with her?

 

[gtx510]

what? no 0W-20 for this vdub?

 

[AEHaas]

Yes, I was going with the wife to Tampa.

I would use 0W-20 in the VW but I have the Castrol GC to use up first.

 

[jaj]

Originally Posted By: AEHaas
Yes, I was going with the wife to Tampa.



This is sounding eerily familiar - when my wife's car needs a run to burn off the fuel and water load from short trips, it's a. not available because she needs it, or b. going for a drive with me is a wonderful idea, but maybe some other time...

 

[AEHaas]

I did another UOA after finally doing a drive to International Mall in Tampa, a total of around 3 hours on I-75.

The fuel dropped to The viscosity is now 10.9 - previously 11.1 with the fuel at 3.0.

This may help show that fuel dilution does not by itself have a big effect on the actual viscosity. It is the presence of fuel that hurts things inside your engine.

aehaas

 

[SubLGT]

Interesting. Thanks for doing these UOAs.

And what was your average speed on I-75?

 

[benjamming]

and maximum instantaneous speed?

it's the carnage that fuel leaves behind, crashing oil, etc. that causes the problems
left unattended it will, of course, eventually affect the viscosity

 

[AEHaas]

The TBN was 5.89 on this latest sample.