Here's the new analysis of the Mobil 1 0w40
1. The mileage was almost the same for the two oil runs (4660 and 4710 mi). The owners manual says to replace at 6000 mi.
2. The first run used Castrol Syntec 10W30. The second used Mobil 1 0w40. The car now has Mobil 1 0w40.
3. The first run used a WIX 51334 filter with a Beta ratio of 95% at 20 microns. The second used a K&N HP-1004 filter with a Beta ratio of 93% at 20 microns. The car now has a PureONE PL14459 filter with a Beta ratio of 99.9% at 20 microns.
4. The first run consisted of a lot of highway driving. The second had more city driving, short trips, and an autocross.
The largest issue in this report is the fuel, up to 2.0% from 0.8% The cause of this is likely due to driving style, short trips and idling. The car did a short trip from cold immediately before the oil change.
When the car was purchased 10,000 miles ago a dry compression test was done: 140, 135, 130, 140 psi on cylinders 1-4.
Mobil 1 0w40 starts off with a viscosity of 13.5 cSt at 100 degC, and because of the fuel and shearing effects it thinned to 10.56 cSt. If the fuel had stayed out of the oil the viscosity would have been higher, resulting in better engine protection. However, the Mobil 1 even with the fuel dilution was thicker than the Castrol 10w30 at the end of the run.
Mobil 1 0w40 starts off with a flashpoint of 446 degf, the fuel dilution reduced this to 335 degf.
TBN was robust, showing a lot of un-reacted additives still remaining in the Mobil 1, however because of the lowering of the viscosity due to the fuel I think it was time to replace the oil.
Comparing formulations between the Castrol Syntec and the Mobil 1 we see that:
Syntec has a little more molybdenum, an anti-wear additive
Mobil 1 has 3x more boron, a corrosion inhibiter, anti-wear and anti-oxidant additive
Mobil 1 has 1.5x more calcium, a detergent and dispersant additive
Syntec has 4.5x more magnesium, a detergent and dispersant additive
Mobil 1 has a little more phosporus and zinc, anti-wear, anti-oxidant additives
Thread cross-references:
LEC
BITOG Run 1
1. The mileage was almost the same for the two oil runs (4660 and 4710 mi). The owners manual says to replace at 6000 mi.
2. The first run used Castrol Syntec 10W30. The second used Mobil 1 0w40. The car now has Mobil 1 0w40.
3. The first run used a WIX 51334 filter with a Beta ratio of 95% at 20 microns. The second used a K&N HP-1004 filter with a Beta ratio of 93% at 20 microns. The car now has a PureONE PL14459 filter with a Beta ratio of 99.9% at 20 microns.
4. The first run consisted of a lot of highway driving. The second had more city driving, short trips, and an autocross.
The largest issue in this report is the fuel, up to 2.0% from 0.8% The cause of this is likely due to driving style, short trips and idling. The car did a short trip from cold immediately before the oil change.
When the car was purchased 10,000 miles ago a dry compression test was done: 140, 135, 130, 140 psi on cylinders 1-4.
Mobil 1 0w40 starts off with a viscosity of 13.5 cSt at 100 degC, and because of the fuel and shearing effects it thinned to 10.56 cSt. If the fuel had stayed out of the oil the viscosity would have been higher, resulting in better engine protection. However, the Mobil 1 even with the fuel dilution was thicker than the Castrol 10w30 at the end of the run.
Mobil 1 0w40 starts off with a flashpoint of 446 degf, the fuel dilution reduced this to 335 degf.
TBN was robust, showing a lot of un-reacted additives still remaining in the Mobil 1, however because of the lowering of the viscosity due to the fuel I think it was time to replace the oil.
Comparing formulations between the Castrol Syntec and the Mobil 1 we see that:
Syntec has a little more molybdenum, an anti-wear additive
Mobil 1 has 3x more boron, a corrosion inhibiter, anti-wear and anti-oxidant additive
Mobil 1 has 1.5x more calcium, a detergent and dispersant additive
Syntec has 4.5x more magnesium, a detergent and dispersant additive
Mobil 1 has a little more phosporus and zinc, anti-wear, anti-oxidant additives
Thread cross-references:
LEC
BITOG Run 1