Truck Odometer: 211300 mi
Miles on oil: 24000
No makeup oil added since last sample.
From Polaris Labs.
Wear Metals @ 12k, 18k, 24k:
Iron; 41 ppm, 60, 71
Chromium; 3, 4, 5
Al; 4, 5, 2
Copper; 4, 6, 8
Lead; 1, 4, 9
Contaminants:
Silicon; 8, 11, 15
Sodium; 11, 15, 18
Multi-source metals:
Moly; 66, 76, 86
Boron; 41, 39, 30
Additive metals:
Mag; 1162, 1193, 1383
Calcium; 1053, 1114, 1227
Phos; 1136, 1188, 1303
Zinc; 1377, 1451, 1549
Fuel Dilution Soot Water
KV100 = 14.2, 14.8, 14.6 cSt
TBN = 6.7, 6.46, 5.55
Oxidation = 12, 13, 14
Nitration = 8, 9, 9
Polaris Comments: Moly and Calcium readings were flagged as being abnormally high for RT6, but no advisory for maintenance action.
The big difference on this oil sample interval was that I decided to not add oil until the level was down to ADD on the dipstick. I've always been diligent about adding a quart when the level dropped to halfway between FULL and ADD. I found that after the level gets halfway down, the consumption decreases. In the first 3000 miles of this interval, the engine used 1 quart, and in the next 3000 miles it only used 1/2-quart. I think from now on, I'll maintain the level at 1 quart down from FULL.
I went ahead and did the oil and filter change at 24,000 miles, and refilled with 11 quarts, instead of the normal 12. Based on the Iron and TBN readings, I could have gone much longer, but this is the first time I have pushed the OCI this far, and I was beginning to lose sleep over it. Next OCI I think will be 30K miles, maybe more.
Miles on oil: 24000
No makeup oil added since last sample.
From Polaris Labs.
Wear Metals @ 12k, 18k, 24k:
Iron; 41 ppm, 60, 71
Chromium; 3, 4, 5
Al; 4, 5, 2
Copper; 4, 6, 8
Lead; 1, 4, 9
Contaminants:
Silicon; 8, 11, 15
Sodium; 11, 15, 18
Multi-source metals:
Moly; 66, 76, 86
Boron; 41, 39, 30
Additive metals:
Mag; 1162, 1193, 1383
Calcium; 1053, 1114, 1227
Phos; 1136, 1188, 1303
Zinc; 1377, 1451, 1549
Fuel Dilution Soot Water
KV100 = 14.2, 14.8, 14.6 cSt
TBN = 6.7, 6.46, 5.55
Oxidation = 12, 13, 14
Nitration = 8, 9, 9
Polaris Comments: Moly and Calcium readings were flagged as being abnormally high for RT6, but no advisory for maintenance action.
The big difference on this oil sample interval was that I decided to not add oil until the level was down to ADD on the dipstick. I've always been diligent about adding a quart when the level dropped to halfway between FULL and ADD. I found that after the level gets halfway down, the consumption decreases. In the first 3000 miles of this interval, the engine used 1 quart, and in the next 3000 miles it only used 1/2-quart. I think from now on, I'll maintain the level at 1 quart down from FULL.
I went ahead and did the oil and filter change at 24,000 miles, and refilled with 11 quarts, instead of the normal 12. Based on the Iron and TBN readings, I could have gone much longer, but this is the first time I have pushed the OCI this far, and I was beginning to lose sleep over it. Next OCI I think will be 30K miles, maybe more.