Holiday Alert... Orders placed now will ship from 6th January 2025. All branches Closed: 20 Dec (5pm) – 2 Jan (8am).

We make both primary & secondary filter kit options for most popular diesel powered vehicles utilizing common rail fuel systems. Both versions of auxiliary filter give effective protection against premature fuel system component damage caused by contamination. We recommend the secondary as being the best option though. This is because the finer micron filter used in the secondary kit (usually 2 micron as compared to 30 micron used in the primary kit) means the fuel entering your high pressure fuel system contains less abrasive particulate matter; so it’s as clean as it can be.

We are regularly asked questions relating to flow restriction or performance loss if an auxiliary filter is fitted. We believe these fears could be because if an inadequate type of filter is used, problems such as power loss or surging could occur. We also think it’s because there is a lot of misinformation out there from a variety of sources which simply has no basis of credibility. We regularly hear these claims & we can say with confidence that the vast majority are made without foundation or evidence. If a suitable filter with adequate fuel flow capacity is used there is no problem with installing an auxiliary filter, in fact it is the single best thing you can do to prolong the life of any diesel injection system. The Fuel Manager filter we use in Diesel Care kits causes no problems with fuel supply or flow; in fact they present very little restriction. If there was any problem at all we wouldn’t use them.

Recently we produced the film clip above and available on You Tube for all to see. We wanted to dispel the myth which constantly raises its head relating to secondary filtration causing flow issues, so we ran a Toyota Hilux on our Dyno over a series of ramp runs & measured:
1) engine output at the wheels
2) fuel supply vacuum
3) fuel return flow.

Firstly we recorded readings with the factory filter only connected, then again with a 2 micron secondary filter added. There was no change to power or return fuel flow, & only a minor increase in vacuum of about -0.5 psi (1”Hg). To emphasise a point we connected yet another 2 micron filter in series, so now we had 3 filters in the system. Once again there was no change in power or return flow, & similar increase in vacuum as the first filter had. We concluded that a 2 micron Fuel Manager filter will present a restriction of less than –0.5 psi (1”Hg) and does not change fuel flow or engine output. As a matter of interest the high pressure pump on a Hilux is capable of pulling a -9 psi (18”Hg) vacuum, the maximum vacuum we measured in our test with 3 filters in place was -4.4psi (8.5”Hg).

It should be understood that any filter will present more restriction as it becomes progressively dirty; this is because it is doing its job. We recommend that fuel filters are changed regularly. In the case of the vehicle factory installed filter; it should be replaced as often as the manufacturer recommends at the very least, & in the case of a Diesel Care auxiliary filter; 20,000kms for a primary filter & 40,000kms for a secondary filter.

We encourage you to watch our You Tube clip & see for yourself that adding a suitable auxiliary fuel filter causes none of the problems that the “forum experts” or “anti aftermarket doomsayers” claim. The evidence is in the testing we’ve done & the thousands of secondary kits we’ve supplied or fitted across Australia to around 40 different makes & models. We’ve saved hundreds (if not thousands) of fuel systems from an early death due to fuel contamination, & contrary to a few of the forum expert’s claims; we’ve caused damage to none.

We hope this information helps you make a decision.

To learn more visit our Diesel Care Filtration Kit Page or to purchase our Fuel Filter Bracket kits please visit our DieselStore

Filter restriction test Vacuum in inches of mercury at CR pump inlet
Filter restriction test - Power at the wheels