Yeah but this filter is never going to clog. And we don't know what the pressure drop PSI is on cold start up, I know the surface area is 2x as much as a 3001, so lets say the PSI drop through the filter is 1/2 as much. So should I weld a bung on a filter and test the pre-filter pressure against galley pressure? that would give us a pressure drop through the filter material itself. I'm thinking there is next to no pressure drop through this filter.

 

The surface are of the media isn't going to change how easily it is to push cold oil through the it.

Even the short stock filter is not going to clog if you change your oil as you should. The bigger risk is at cold start up and the risk level is going to depend on the ambient temp, oil viscosity and type of oil.

Sure, you could run some tests, but you would have to test a lot of variables and I just don't see enough, if any, advantage to higher PSI bypass setting to make it worth it.
Filters like this aren't new and I think if there was an advantage to a high bypass PSI, Rover would have specified one.

Personally, I can't use the filter as it won't clear my steering damper, but if I were to use one this size I'd choose the lower psi version.

 

People may be interested in the online training videos from Hastings.
Online Training | Lube

They can be a bit dry, but keep in mind that Hastings and Wix's primary customers are fleet users.

 

I contacted Purolator in Fayetteville NC. I first got the "claims lab", they actually process and research claims issues related to filters. Who knew? They sent me to the filter hot line, 800-526-4250. There I found that the MANN W950/7 is the Purolator L40107.

When I asked for the layman's explanation, it was pretty much what WIX told Tom, on a cold start, with thick oil, the pressure differential forces the bypass valve open, oil flows around the filter, and when it warms up the filter begins to process all of the oil flow. The main reason for this is to bypass a clogged filter. Each factory specs the bypass range they want (bet that has something to do with the claims lab also). So with the 35 PSI bypass, on a cold start it would try to shove cold oil through the filter media over a wider range than the 10 PSI rated filter. How much oil flow would depend on oil viscosity, temperature, etc.

So the cold start performance is probably a wash when compared to a smaller filter with less media. Next time I'll buy the L40107, even though I have not noticed any change in cold crank up with 5W40 Rotella. No oil gauge here (yet).

 

A larger surface area decreases the speed at which the oil has to pass through it, thereby lowering pressure drop through the filter at any oil temperature. (this is evident in my pressure tests with just changing the filter from purolator to mann, and seeing the oil pressure at the galley increase. (yes the old filter MAY have been dirty thereby increasing pressure drop, but with only 400 miles on the old filter the pressure difference could be at best within the margin of gauge reading error))

What I'm saying is the pressure drop may never exceed 10 PSI, (under any normal circumstance, cept' clogging solid ofc) rendering any bypass valve useless.

But your completely right about the bypass at 10 PSI, I also see no benefit for the valve to open above 10 PSI, unless you really want to make sure every drop of oil getting pumped is filtered.

 

Now I am going to throw a monkey wrench into the mix, I think the only true way to compare oil PSI numbers is by using the exact same oil filter.

 

Ok.... I figure this is the perfect thread for my question. I recently purchased an 04 Disco, series II, seriously pampered. This truck has 111k on the clock and was a 1 owner truck, with the owner using Mobil 1 synthetic every 7000 mikes since day 1. This motor does have a tick, but I've read they all do.... Kinda let's you know she's running, and it does tend to come and go. My question is should I continue the Mobil 1, or switch oils and why? Thank you in advance for all your infinite wisdom, fellow Rover lovers.

 

Switch to the Shell Rotella 15w-40, change it every 5,000 miles.
Why?
Because Mobil 1 is overpriced crap and I bet your tick goes away after you make the switch.
You will be happy with the switch, your engine will be happier and your wallet will be too.

 

currently im using the WIX. If try out that monster Purolator/Mann filter on my next oil change what does that bump oil capacity up to? id imagine it'd be near 7qts

 

This is the single greatest piece of advice I've gotten from this forum. I run the full syn Mobil 1 in our Mazda 3 2.5L and it's great....but the Rover HATES it.
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And now, back to your regularly scheduled oil filter debate