I recently bought a new Suzuki. Suzuki motorcycles come with a very non-standard 20mm x 1mm thread size, with the result that your choice for filters is quite limited, and there are no automotive filters that will fit. So, I decided to take some filters apart and see for myself what the available options are and how they compare.
The nominal specification for the Suzuki filter is 20 x 1mm threads, 11 psi by-pass valve, anti-drain back valve. The columns below are Media pleats * depth * height, media square inches, anti-drain back valve material, seal material, Mechanical grade, Media grade. In these days of rampant grade inflation, I feel compelled to point out that here "C" means average. I'm not interested in the filter's self-esteem.
I get a lot of emails from Suzuki owners asking me what the secret best filter is. They're all trash. All of them. You are forced by Suzuki's brain-damaged specification to buy and use trash oil filters. There's now an alternative, you can buy an adaptor for $15 that allows you to use PL14610 or Supertech ST7317 filters, the same thing used by Honda, Yamaha and Kawasaki bikers.
I bought these filters with my own money, and as should be apparent, I got no use out of them in terms of filtering oil.
|$8.75||45*.37*1.1||37||Nitrile||Nitrile||C||B||Advanced media, but not much of it. A flawed superior filter.|
|$6||61*.48*1.3||76||Nitrile||Nitrile||C||C||Good alternative to OEM|
|$7.75||35*.3*1.24||26||Nitrile||Nitrile||C||B||Advanced media, but not much of it. A flawed superior filter.|
|$6||44*.49*1.77||76||Nitrile||Nitrile||F||C||Normal filter paper, and a decent amount of it. Cardboard end caps, Little prongy plastic bypass valve. Unconvincing anti-drainback valve. A study in how to make a filter on the cheap.|
|$5.50||49*.51*1.6||80||Nitrile||Nitrile||C*||C||An average filter at a competitive price.|
|$6||on order. . .|
|K&N 138||$12||62*.315*1.52||59||Nitrile||Nitrile||C+*||C||Made by Hi Flo. Average filter with a $6 nut welded onto the end cap.|
|$9||49*.365*.97||34||Nitrile||Nitrile||C||C-||Bypass filter added on, not built in. Filter media in short supply.|
|Parts Unlimited||$9||50*.41*1.46||60||Nitrile||Nitrile||C||C||Average filter, high price.|
|Not tested at this time.|
|Not tested at this time.|
|STP SMO-18||$6||49*.38*1.3||48||Nitrile||Nitrile||C||C-||Filter media in short supply. Below average.|
|$12||59*.41*1.47||71||Silicon||Nitrile||B||C||A slightly better than average filter at a super-premium price.|
|$11||on order. . .|
STP, Emgo 55662, Emgo 55660, Suzuki, Fram Oil Filters.
K&N, Hi-Flo, Parts Unlimited, Napa Gold, AMSOil Oil Filters.
Pure One, Bosch, SuperTech Oil Filters.
|Bosch 3300||$6||49*.36*1||34||Nitrile||Nitrile||C||B||This is the smaller unit. Nice filter media, but not much of it.|
|$12||43*.39*.96||32||Silicon||Nitrile||B||B||This is the smaller unit. Nice filter media, but not much of it. This was a used filter, hence the color of the media.|
|$6||50*.39*2.36||92||Silicon||Silicon||A||A||This is how an oil filter should be made. The anti-drainback valve is double the thickness of any other here, and obviously seals very well. The media is the best available, and there's a lot of it. The bypass valve is made from a laser-cut piece of stainless steel, and just can't bind or jam.|
|$2||33*.36*1.9||49||Nitrile||Nitrile||C||B||A better than average filter at a bargain price.|