Since the VW/AUDI 1.8T seems to be a frequent application request I thought this might make a useful post.
The Germans appear to like filters with reinforced media and a relatively high (30lb+/-) filter bypass valve. No problem, they factor the whole package with that in mind.
Now this is fine for your Porsche that spec's 5w-40 and peg's the gauge @ 135psi for the first 10 minutes you're driving. If not for the higher bypass threshold, the engine's entire life could be in some variable level of unfiltered oil. Most of us only drive 20 minutes and the Euro's tend to make cars that can drive at near 100% output 24/7. Good packages. These demands/capabilities usually require higher visc fluids and, at times, higher volume oil flows. During startup this can put the oil pump in relief and the ONLY time the filter can present a substantial resistance to flow in terms of true "pressure drop". Once the relief on the pump is closed, there's NOTHING THAT CAN INHIBIT THIS FLOW. The oil will just gain or lose velocity as it travels through things. This also makes the engine THE MUCH MORE DOMINANT RESISTIVE ELEMENT in a series fluid circuit. The filter MUST fall into some subordinate relative resistance in ratio to the engine. A simple series circuit ..fluid or D.C. electric (with current being the determining element).
Oil pumps not in relief are not like wall outlets or water spigots. There you have a pressure/restriction = resultant flow. Oil pumps out of relief form a flow/restriction= pressure model.
Now oil pumps IN RELEIF DO resemble your more common view. There you have a pressure limit and that will produce flow to the filter/engine combination that will add up to that number. Here, in this state, the filter CAN offer substantial resistance to flow. Think of how hard it is to pour oil through a filter vs. just air? Same thing indexed at any pressure. The higher the pressure applied, the higher the "pressure differential" WHEN IN THIS OIL PUMP PRESSURE RELIEF STATE.
Now this will confuse some of you, but here's how it plays out
100psi (pump pressure limit for demonstration)
Here's how it CAN work out with the spec'd filter in a NORMAL VW/AUDI engine
100psi 30lbs dropped across filter - 70lbs across engine
That is 30% shunted flow
As the pump relief begins to close
100psi - 25psi across filter 75lb across engine 100psi - 20psi across filter 80lb across engine 100psi - 10psi across filter 90lb across engine 100psi - 5psi across filter 95lb across engine 95lb ....- 2psi across filter 93lb across engine
etc...etc..etc.
As you MAY be able to see the filter retreats to nearly invisible. This is the same for all positive displacement fixed mechanical oil pumps at least for this transitional event.
Now here's what can happen when your filter is clogged.
Chrysler Family of Cars/Trucks (57-70), Ford Family of Cars/Trucks (57-00), Mazda Trucks (94-00), Toyota Landcruiser (71-96), various HD applications - (Two Quart version is 51773)
For those wanting to use a filter with reinforced media like your OEM specified filters, the FRAM XTENDED GUARD (XG prefix) is one such filter in wide distribution/availability.
-- Edited by geeaea on Tuesday 22nd of February 2011 11:20:20 AM
-- Edited by geeaea on Tuesday 22nd of February 2011 11:26:53 AM
-- Edited by geeaea on Saturday 5th of March 2011 12:26:51 AM
Here is the Wix "Big Kahuna" size for this application:
Part Number: 51333 UPC Number: 765809513334 Principal Application: Volvo 760 GLE w/2.4L Turbo Diesel Engine (83-87) Style: Spin-On Lube Filter Service: Lube Type: Full Flow Media: Paper Height: 6.982 Outer Diameter Top: 3.670 Outer Diameter Bottom: Closed Thread Size: 3/4-16 By-Pass Valve Setting-PSI: 30 Anti-Drain Back Valve: Yes Burst Pressure-PSI: 300 Max Flow Rate: 7-9 GPM Nominal Micron Rating: 21
Gasket Diameters Number O.D. I.D. Thk. Attached 2.834 2.462 0.200
Because this filter fits the 1.8T (at least in the Passat application) there is plenty of room for the Motorcraft FL-1A. As one can see from from the specifications the FL-1A is substantially larger than the FL-400S.
A quick note about "Beta Ratios". Wix is now providing Beta Ratio information on some of it's filter's. This information is more accurate than the older Normal Micron Rating which was expressed as a single number. To avoid any confusion between the two ratings disregard the Normal Micron Rating information if the newer Beta Ratio is listed.
-- Edited by TurboJim on Friday 25th of February 2011 11:36:26 AM
For those Euro owners who have a concern about using a filer without the mesh reinforced media that all the Euro spin-on filter require due to the relatively high filter bypass valve rating, the FRAM XTENDED GUARD has this feature even in the most common configurations. It's about the most expensive Fram filter, but is also about the only one that can justify its added cost.
A XG prefix denotes the XTENDED GUARD. Hence if FL1A (PH8A in Fram) is the size you're looking for, then XG8A would be a filter of relatively wide availability that you could use for added peace of mind.
The subject of filter's is often brought up with regard to the 1.8T, especially for the Passat / Audi A4. Even with the larger filter now spec'd by VW for this engine the oil capacity remains below that of 1.8T's in other applications.
I asked Champion Laboratories, a supplier of filters to VW in North America, to comment about the specifications of their Mobil 1 M-301 oil filter with regard to VW's oil filter specifications.
The VW spec is approximately 30/35 psid @ 1.0 (one) liter per minute flow rate. The M1-301 filter is rated at 8/11 psid @ 0.1 (1/10) gallon per minute flow. The slight difference in opening pressure will not be detrimental to the life of the engine. The filter spends little time in relief mode, briefly occuring at cold start. We believe that oil flow to engine bearings, although briefly un-filtered at start-up, is crucial to engine life.
You will note that the Mobil 1 M-301 and the Motorcraft FL400S size Wix 51516 share the same 8/11 psid specification. When the engine oil is up to normal operating temperature, and if the oil filter's flow was not restricted internally with excessive contaminant, then the VW's spec'd filter would operate the same as the Ford spec'd filter. All oil entering would be filtered, none would escape through the by-pass valve.
During a Auto-Rx treatment contaminant is removed from engine and trapped in the oil filter. Should the contaminant over tax the filter's dirt holding capacity then oil will still reach the engine, but to do so the filter must go into by-pass.
The 1.8T's oil pump pick-up screen can become clogged with small carbon shards of oxidized oil. This severely restricts the oil pumps ability to produce a safe amount of oil flow. It is under these conditions, of reduced oil pump output, that a oil filter having a 8/11 psid is much preferable to one having a 30/35 psid specification
-- Edited by TurboJim on Thursday 28th of April 2011 10:11:10 AM