Used oil analysis on 2000 Ford F150 w/5.4L, auto trans, tow package. Driven 6 mi one-way to work (apx 15 min run time) in ambient temp of 40 deg winter a.m.'s, 60 deg winter p.m's, 70 deg summer a.m.'s, 80-90 deg summer p.m.'s. First oil change at 2,000 mi. All subsequent changes at apx 5,000 with GTX at American Fast Lube. (Changed "early" this time as I am now towing a 3000# boat on the weekends as much as I can.)

Miles on unit 31,137. Miles on oil 3,782. Time on oil 5 months. No make-up oil. Castrol GTX 10w30 from bulk. Warner (Champion Labs) oil filter. Air filter (Warner) replaced at apx 15,000 miles and this change.

Test done by Blackstone on 7-11-03.

ALUMINUM 5
CHROMIUM 1
IRON 19
COPPER 9
LEAD 0
TIN 0
MOLYBDENUM 43
NICKEL 1
MANGANESE 1
SILVER 0
TITANIUM 0
POTASSIUM 0
BORON 4
SILICON 9
SODIUM 2
CALCIUM 1695
MAGNESIUM 6
PHOSPHORUS 775
ZINC 966
BARIUM 0
VISCOSITY SUS @ 210F 56.6 (mid-20 weight)
FLASH 410
TBN 1.2
FUEL <0.5
ANTIFREEZE 0.0
WATER 0.0
INSOLUBLES 0.5

Blackstone comments: "Nothing too unusual ... all wear read well within the average range for this type engine, which is a very good indication of normal wearing parts ... normal wear after about 4,000 miles on oil ... good oil filtration ... TBN was low ... [TBN] probably started out around 7 ... viscosity was low ... try 4,500 on the oil next time."

My comments: Try 4,500 on the oil next time? No way. This oil was shot. Oil sheared-down big time. Started off as a mid-30 weight at temperature. Running an Auto-Rx cleaning now before switching to Chevron Supreme or Pennzoil.

 

In regards to the low TBN, Blackstone has been having problems with their TBN results coming in at half of previously tested media. I wouldn't put a lot of faith in this particular TBN. I will agree though, the type of driving that you do will be murder on any oils TBN as acids are quick to form during cold startup and then the engine is shut down before it gets a chance to burn off the contaminants. The elevated iron is most likely surface rust that forms overnite in cold, damp emvironments. I would suggest that you change oils to one of the ones that you have selected and have it analized. If possible, you may want to add some miles to your morning commute to let the engine cook off some of the contaminants. You may also want to consider a CH-4 rated oil as they will have a higher virgin TBN. I believe the 10w-30 Motorcraft is rated at CH-4 and has a TBN of 10.0- might want to check that though as I am not at the office. www.motorcraft.com Hope this is of value.

 

When Oil Analyzers tested my oil the TBN came back a 3.5. The Amsoil posted TBN for my oil was 9.0 new. The tech at Oil Analyzers told me that they use a different TBN test for used oil than what is used to test new oil. He gave me the actual test numbers but I don't have them here. He said had my used oil been tested with the same test that was used to get the starting TBN it would have read in the 6.0 range. Keep that in mind when you read posted TBN numbers.

 

There are indeed two different TBN test methods. When comparing the TBN of virgin oil to used oil it is important that the same method was used or it's like comparing apples and oranges. Under one test method a TBN of somewhere around 3.0 or less would indicate the oil had outlived its useful line while under another method a TBN of less than 1 would indicate the same. The test method Blackstone used on this analysis was the one that yielded the lower number. It must also be kept in mind that it takes some amount of skill to achieve consistent results when performing the TBN test. It is not a mathematical computation.