quote:Originally posted by GeeAea:
While on the surface I would conclude that both the M1 and P1 are superior to the EaO, you've got to keep multipass ratings in perspective.
The reason this is so is due to the protocol used to rate a filter. The multipass tests required loading of the upstream fluid until the filter is saturated ..aka SHOT.
So you're not dealing with anything absolute right out of the box. You're reaching that level at the end of life.
The nominal rating is more indicative of sensible filter performance.
If you tracked the M1 vs. EaO over 5k and 10k on BITOG, you saw the EaO begin to catch up. The owner wasn't willing to entertain using the 5k or 10k filters over again to determine the performance in 15k-20k range.
The EaO is a 25k/1 year filter under just about all conditions. The M1 is a 15k one year filter where a one year OCI is sensible (which would be probably around 15k) The PureOne is (probably) a 15k/one year filter (same deal).
To make a better example, you could probably use an EaO over 4 or 5 5k OCI's ..3 with the M1 or PureOne. During the first 2, the M1 and PureOne will probably filter better. They're deeper into their lifespan toward saturation. Closer to their multipass rating.
Amsoil needed a ONE YEAR filter to compliment their ONE YEAR lubricants. They no longer needed to have intermediate filter changes to replenish additives. Hence, the EaO.
Nomimal rating is done via measuring pores under a microscope.
Beta ratings ARE multipass efficiency. With particle counters on stream.
Betas are the standard.