Castrol GTX 20w-50, 11,500 miles (2 years), BMW 735il
- Thread starter T-Keith
- Start date
- Status
This is the first UOA we have seen on this weight GTX. Looks like excellent results for the abuse.
I use this in my TR3 and my old Toyota with 260,000 miles. I never go past 6000 miles with it. Looks like it was a good choice.
I use this in my TR3 and my old Toyota with 260,000 miles. I never go past 6000 miles with it. Looks like it was a good choice.
Not THAT bad.
TBN would have been interesting.
The whole Blackstone Uni. Ave. thing is sorta BO-GUS in my book (JUST MY HUMBLE OPINION)....unless they state the sample pool they used for the average, the SD, etc...
TBN would have been interesting.
The whole Blackstone Uni. Ave. thing is sorta BO-GUS in my book (JUST MY HUMBLE OPINION)....unless they state the sample pool they used for the average, the SD, etc...
Hey, when I drained that stuff, I was expecting triple digit numbers, so I was pleasantly suprised. I should note that while the oil "didn't thicken out of grade", it flowed very slowly at non-operating temp. I am sure the pour point depresants had left the seen, as I warmed the car up for about 3-4 minutes on a 60 degree day and it still took 10 minutes for the oil to drain.
TBN- I thought about getting one, but it wasn't worth it as I knew the oil was done. Also, to the extent it showed any remaining life, it would have been from the quart of 15w-40 HDEO added a week before.
Cary
So this is an oil sample I pulled after checking the oil in my Mother in law's car and asking how long it was since it was changed. After she explained how difficult it is to get the oil changed because she has to wait, I went and picked up a filter at her mechanic's (who I am friends with) and a search of his records showed the last oil change in October 2002, with the one prior to that in December 2000 (this is why I know the oil type used and the mileage since last change). She purchased the car with 130,000 miles, so I do not the know the prior maintence history, but it appeared to be well cared for.
Interesting to note, I did a full tuneup when I changed the oil. Since this is a M30 BMW engine, I had to adjust the valves. There was NO sludge at all, with just a thin vanish buildup in the head as I have seen in many BMW motors. Also, this car sees many short trips. Finally, I don't know how much makup oil was added during the two years, except for the quart of Chevron Delo 400 15w-40 I put in one week prior to the change. I have put the car on a twice a year diet of Delo 15w-40 from now on.
Miles on Vehicle: 161,898
Miles on Oil: 11,500
(Items in Bold were flagged)
Element- UOA (Universal Averages for 4100 Miles)
ALUMINUM- 10(5)
CHROMIUM- 13 (1)
IRON- 36(13)
COPPER- 14(7)
LEAD- 7 (9)
TIN- 0 (1)
MOLYBDENUM- 51 (88)
NICKEL- 4(0)
MANGANESE- 1 (0)
SILVER- 0 (0)
TITANIUM- 0 (0)
POTASSIUM- 7 (1)
BORON- 9 (28)
SILICON- 8 (6)
SODIUM- 11 (9)
CALCIUM- 2111 (2067)
MAGNESIUM- 39 (129)
PHOSPHORUS- 777 (889)
ZINC- 1025 (1076)
BARIUM- 0 (0)(0)
SUS@ 210F- 83.9 (should be 82-95)
FLASH PT- 425 (should be greater than 385)
Less than .5% fuel found
0.0% antifreeze found
0.0% water found
0.5% insoluables found
Blackstone Comments:
This oil was run two years and you're right it was way overdue. Wear was extremely high, expecially in the upper-end (alumium, chrom, and iron from pistons, rings, and cylinders respectively), the the oil itself was not in bad shape. The viscosity was normal for 20w/50 and insolubles were still below limits. No fuel dilution or anti-freeze showed up. Universal averages show normal wear from the BMW 3.5L after about 4,100 miles on the oil. Suggest running the next oil nor more than 3,000 miles and resample to monitor. Wear should improve.
My Thoughts:
This oil went a long time, longer than it should have. That said, I expected the numbers to be much worse. When you adjust the universal averages out to 12,000 miles, you see that the numbers that this motor turned in are not out of line. It makes me question how much benifit there is to a good synthetic over mineral in some motors. Obviously, this motor is easy on oil and does not have sludge issues (it holds 6 quarts which helps).
Interesting to note, I did a full tuneup when I changed the oil. Since this is a M30 BMW engine, I had to adjust the valves. There was NO sludge at all, with just a thin vanish buildup in the head as I have seen in many BMW motors. Also, this car sees many short trips. Finally, I don't know how much makup oil was added during the two years, except for the quart of Chevron Delo 400 15w-40 I put in one week prior to the change. I have put the car on a twice a year diet of Delo 15w-40 from now on.
Miles on Vehicle: 161,898
Miles on Oil: 11,500
(Items in Bold were flagged)
Element- UOA (Universal Averages for 4100 Miles)
ALUMINUM- 10(5)
CHROMIUM- 13 (1)
IRON- 36(13)
COPPER- 14(7)
LEAD- 7 (9)
TIN- 0 (1)
MOLYBDENUM- 51 (88)
NICKEL- 4(0)
MANGANESE- 1 (0)
SILVER- 0 (0)
TITANIUM- 0 (0)
POTASSIUM- 7 (1)
BORON- 9 (28)
SILICON- 8 (6)
SODIUM- 11 (9)
CALCIUM- 2111 (2067)
MAGNESIUM- 39 (129)
PHOSPHORUS- 777 (889)
ZINC- 1025 (1076)
BARIUM- 0 (0)(0)
SUS@ 210F- 83.9 (should be 82-95)
FLASH PT- 425 (should be greater than 385)
Less than .5% fuel found
0.0% antifreeze found
0.0% water found
0.5% insoluables found
Blackstone Comments:
This oil was run two years and you're right it was way overdue. Wear was extremely high, expecially in the upper-end (alumium, chrom, and iron from pistons, rings, and cylinders respectively), the the oil itself was not in bad shape. The viscosity was normal for 20w/50 and insolubles were still below limits. No fuel dilution or anti-freeze showed up. Universal averages show normal wear from the BMW 3.5L after about 4,100 miles on the oil. Suggest running the next oil nor more than 3,000 miles and resample to monitor. Wear should improve.
My Thoughts:
This oil went a long time, longer than it should have. That said, I expected the numbers to be much worse. When you adjust the universal averages out to 12,000 miles, you see that the numbers that this motor turned in are not out of line. It makes me question how much benifit there is to a good synthetic over mineral in some motors. Obviously, this motor is easy on oil and does not have sludge issues (it holds 6 quarts which helps).
Is this conclusion correct?
1. The oil is not worn out
2. The oil is not dirty
3. The motor IS full of wear metals
Then that's the reason I have to change the oil. Wear metals. I guess the filter doesn't catch it because it's not suspended in the oil. I should UOI mine in order to set OCI. light bulb
What would suspend more wear metals? 20 or 40 weight.
Joe
1. The oil is not worn out
2. The oil is not dirty
3. The motor IS full of wear metals
Then that's the reason I have to change the oil. Wear metals. I guess the filter doesn't catch it because it's not suspended in the oil. I should UOI mine in order to set OCI. light bulb
What would suspend more wear metals? 20 or 40 weight.
Joe
I wouldn't say the oil is FULL of metal.
Cr is quite high,though.
Cr is quite high,though.
Is it not more of a function of the additive package to hold particles in suspension and carry them to the filter?? Both of which were shot at this point.
This probably caused ring wear, imho. Abrasive action? Hence chromium.
Extended drains require renewing the filter and boosting the additives to have a chance.
This probably caused ring wear, imho. Abrasive action? Hence chromium.
Extended drains require renewing the filter and boosting the additives to have a chance.
This oil was done with and used past when it should have. The only suprise for me was the wear numbers were not higher than they were. A good synthetic run this long (which would have still been to long because of the 2 years) would likely have had much lower chromium, aluminum, lead, nickel, iron, and copper levels.
The weight of the oil doesn't matter in suspending these particles as they are so small.
Really good when considering this is not a longlife motoroil.
- Joined
- Sep 28, 2002
- Messages
- 39,799
I believe you're thinking of offending particles (chunks) ..and not resultant particles. You can't filter to the particle level which is
I understand your point, thanks, but where did the ring wear come from unless the additive package was shot? I was thinking grit, but maybe just a lack of A/W agents.quote:
Originally posted by Gary Allan:
I believe you're thinking of offending particles (chunks) ..and not resultant particles. You can't filter to the particle level which is
- Status