Hello everyone,
Two comments/questions on this UOA, which I would like to point out and obtain the collective wisdom of the readers of this group:
1) Although I am very pleased with this latest UOA, I am puzzled by the consistent downward trend in the TBN rating. In fact, I am rather surprised at how low the TBN is after only 5,025 miles. What could be causing this? Note that the truck has been operated in as consistent manner as possible across the 4 UOAs - Same driver, same brand of gas used, same type of service, etc. The truck runs great - no engine problems. I know many on this group are not Mobil 1 EP fans, but I think there's something besides the oil making this happen. To support my reasoning, I am using the same oil in my other vehicle, a V8 Lexus. I've been running up to 7500 mile UOA intervals, over periods as long as 8 months, and the TBNs on that vehicle are in the 5-6 range. I know this is a different vehicle, but some of the variables are the same - climate, drivers, brand of gas, etc. If Mobil 1 EP were that bad, I would expect the TBN retention to be poor on that vehicle, as well, but it isn't. What could be causing the poor TBN retention on the Tundra?
2) For those of you interested in filter performance, note that I now have two UOAs using the Mobil 1 filter, and two on the Amsoil EaO filter. The Mobil 1 filter seems to be doing slightly better. Currently, I have switched back to the Mobil 1 filter; we'll see what the particle count looks like on the 5th UOA - if it improves a little, then I intend to stick with the Mobil 1 filter. This is not meant to be a poke at Amsoil filters - it seems to be an excellent filter. Perhaps its performance would be better over a longer UOA period, which I will not do as the truck is still under warranty, and Toyota requires 5K oil change intervals. Comments on the filter performance?
Two comments/questions on this UOA, which I would like to point out and obtain the collective wisdom of the readers of this group:
1) Although I am very pleased with this latest UOA, I am puzzled by the consistent downward trend in the TBN rating. In fact, I am rather surprised at how low the TBN is after only 5,025 miles. What could be causing this? Note that the truck has been operated in as consistent manner as possible across the 4 UOAs - Same driver, same brand of gas used, same type of service, etc. The truck runs great - no engine problems. I know many on this group are not Mobil 1 EP fans, but I think there's something besides the oil making this happen. To support my reasoning, I am using the same oil in my other vehicle, a V8 Lexus. I've been running up to 7500 mile UOA intervals, over periods as long as 8 months, and the TBNs on that vehicle are in the 5-6 range. I know this is a different vehicle, but some of the variables are the same - climate, drivers, brand of gas, etc. If Mobil 1 EP were that bad, I would expect the TBN retention to be poor on that vehicle, as well, but it isn't. What could be causing the poor TBN retention on the Tundra?
2) For those of you interested in filter performance, note that I now have two UOAs using the Mobil 1 filter, and two on the Amsoil EaO filter. The Mobil 1 filter seems to be doing slightly better. Currently, I have switched back to the Mobil 1 filter; we'll see what the particle count looks like on the 5th UOA - if it improves a little, then I intend to stick with the Mobil 1 filter. This is not meant to be a poke at Amsoil filters - it seems to be an excellent filter. Perhaps its performance would be better over a longer UOA period, which I will not do as the truck is still under warranty, and Toyota requires 5K oil change intervals. Comments on the filter performance?