Blackstone Report
Engine: GM 3100 V-6
Vehicle: '94 Pontiac Grand Prix SE 4door
Vehicle Mileage: 198,022
Oil Mileage: 6022
Interval Dates: 8/8/06 thru 12/03/06
Oil Type: Mobil 1 5W-30
Make-up Oil Added: 1 Qt of Castrol Syntec 5W-50 at 2000 miles into the interval (partial drain)
No oil additives, Used Gumout Regane fuel system cleaner once
Oil Filter: Wix
Air Filter: Wix
Driving Style: 2/3 Hwy and 1/3 City, mostly 30 mile 1 way driving to work and back.
I initially filled the engine with 4.5 qts of Mobil 1 5W30 but after seeing my UOA results from last time and hearing suggestions of a thicker oil for my older high mileage car I decided to experiment. I wouldn't normally mix like this but this car is approaching disposable due to rust, miles, and general old age so I figured it wouldn't hurt me any even if it did hurt the car. I forgot to write it down at the time but based on my oil purchase receipt of the 5W50 I figure it was right about at 2000 miles into the OCI that I drained about a quart of the Mobil 1 5W30 and added a quart of Castrol Syntec 5W50.
First column is the most recent UOA and the 2nd column is from last time with 100% Mobil 1 5W30. Last UOA was with 6,012 miles on it.
Aluminum: 3, 2
Chromium: 0, 0
Iron: 15, 11
Copper: 6, 4
Lead: 8, 21
Tin: 0, 0
Molybdenum: 82, 75
Nickel: 0, 0
Manganese: 0, 0
Silver: 0, 0
Titanium: 0, 0
Potassium: 0, 2
Boron: 41, 45
Silicon: 13, 14
Sodium: 7, 7
Calcium: 2210, 2241
Magnesium: 17, 19
Phosphorus: 610, 583
Zinc: 737, 708
Barium: 0, 0
SUS Viscosity @ 210 degrees: 66.0, 59.9
Flashpoint: 380, 395 degrees F
Fuel: < 0.5% same
Antifreeze: 0.0% same
Water: 0.0% same
Insolubles: 0.3% same
TNB: 3.5, 2.1
Blackstone thought the mixing was pretty successful and brought my lead down. I can't say it is conclusive since I've only ever had the 1 other UOA however. Who knows what might have happened if I had't of mixed. I certainly can't complain with this report, it looks good to me. Iron went up slightly. My TBN was 3.5 instead of 2.1 and they suggested I go 7k instead of 6k for the next interval. The increase of TBN might be entirely due to the partial drain and refill of 1 quart 2k into the OCI. I'll probably stick to 6,000 for the next OCI. The oil definitely shows that it is thicker, 66.0 versus 59.9 SUS @ 210 F.
Engine: GM 3100 V-6
Vehicle: '94 Pontiac Grand Prix SE 4door
Vehicle Mileage: 198,022
Oil Mileage: 6022
Interval Dates: 8/8/06 thru 12/03/06
Oil Type: Mobil 1 5W-30
Make-up Oil Added: 1 Qt of Castrol Syntec 5W-50 at 2000 miles into the interval (partial drain)
No oil additives, Used Gumout Regane fuel system cleaner once
Oil Filter: Wix
Air Filter: Wix
Driving Style: 2/3 Hwy and 1/3 City, mostly 30 mile 1 way driving to work and back.
I initially filled the engine with 4.5 qts of Mobil 1 5W30 but after seeing my UOA results from last time and hearing suggestions of a thicker oil for my older high mileage car I decided to experiment. I wouldn't normally mix like this but this car is approaching disposable due to rust, miles, and general old age so I figured it wouldn't hurt me any even if it did hurt the car. I forgot to write it down at the time but based on my oil purchase receipt of the 5W50 I figure it was right about at 2000 miles into the OCI that I drained about a quart of the Mobil 1 5W30 and added a quart of Castrol Syntec 5W50.
First column is the most recent UOA and the 2nd column is from last time with 100% Mobil 1 5W30. Last UOA was with 6,012 miles on it.
Aluminum: 3, 2
Chromium: 0, 0
Iron: 15, 11
Copper: 6, 4
Lead: 8, 21
Tin: 0, 0
Molybdenum: 82, 75
Nickel: 0, 0
Manganese: 0, 0
Silver: 0, 0
Titanium: 0, 0
Potassium: 0, 2
Boron: 41, 45
Silicon: 13, 14
Sodium: 7, 7
Calcium: 2210, 2241
Magnesium: 17, 19
Phosphorus: 610, 583
Zinc: 737, 708
Barium: 0, 0
SUS Viscosity @ 210 degrees: 66.0, 59.9
Flashpoint: 380, 395 degrees F
Fuel: < 0.5% same
Antifreeze: 0.0% same
Water: 0.0% same
Insolubles: 0.3% same
TNB: 3.5, 2.1
Blackstone thought the mixing was pretty successful and brought my lead down. I can't say it is conclusive since I've only ever had the 1 other UOA however. Who knows what might have happened if I had't of mixed. I certainly can't complain with this report, it looks good to me. Iron went up slightly. My TBN was 3.5 instead of 2.1 and they suggested I go 7k instead of 6k for the next interval. The increase of TBN might be entirely due to the partial drain and refill of 1 quart 2k into the OCI. I'll probably stick to 6,000 for the next OCI. The oil definitely shows that it is thicker, 66.0 versus 59.9 SUS @ 210 F.
