Are these filters really suitable for the 4.0 Discovery 2. I have a 2001 and see they are available at Advanced auto parts BUT it says not for 2001 discovery, and how much more oil should be added to the oil change to compensate forthe bigger filter??

 

Usually right at 6 quarts. That filter should work, there are better quality filters out there if you want to pamper your engine, like the K&N 3001, Mobil1-310 for the Napa Gold.

 

That filter is fine, figure on a extra quart of oil, fill the filter with oil before putting it on the truck.

 

OK looking on the MANN site there are two filters that go by the same # L40316.....The MANN # is different but the puralator # is the same
Mann #W950-4 has a Bypass Valve Pressure of 2.5 Bars and the W950-7 has a bypass pressure opening of 0.7 bar What is the difference and which is better. I see alot of dicussion about pressure difference on here But can you explain to me what the difference is and which would be better? Thanks

 

The W950/7 is also a Purolator L40107 per a phone call I made to Purolator tech support. The bypass pressure rating is the pressure that must exist across the filter for it to go into bypass mode and sends just unfiltered oil to engine. It does not turn off the flow of oil. If filter was very dirty, it could go into bypass. But when oil is really cold filter could go into bypass as cold oil is harder to push through. This is offset by the increased size of the filter media IMHO. I have a Purolator L40316 on my truck at this point. 44 PSI cold idle or 2500 rpm. 42 PSI hot 2500, 24 PSI hot 700 rpm. I believe I'll try the L40107 next time. RoverMasterTech got hot PSI readings at 2500 rpm in the 60+ PSI range on a D2.

 

I understand higher oil pressure is good ....BUT should you be concerned that maybe being so high could cause an unwanted oil leak somewhere? Oh by the way I am going to run some Rotella 5w40 with a K&L filter on my D2...then switch filters during the next oil change. Going to research the "Larger" canister to see if "Bigger is Better". OPinion!!

 

The larger filter provides extra oil capacity, which is good. Compared to some filters, it will provide a pressure boost, depending on your oil pump. It won't makes any more leaks than you already have, not that big a change. It does filter under 20 microns, which is the cut off point that a number of engineers consider, particle below that size are not much of an issue. A human hair is like 60 microns in diameter, so we are talking small.

 

the more filter matter you have in the filter the more it can catch, undoughtedly . but the Mann #W950-4 has a Bypass Valve Pressure of 2.5 Bars is just to high, the Mann #w950-7 would be closer to the stock rover filter.
You can have to much oil preasure which is the different between a high preasure oil pump and a high volume oil pump, you never want to run a high preasure you want high volume.
Thw Mann is a nice big filter but like DM said there are better filters not as large but they trap smaller particales.
jmho

 

A higher surface area is going to result in a lower PSI at the media, at a given pump flow & PSI. Once the oil is warmed up and the filter is pressurized it's not going to matter, but with cold oil trying to get pushed through the filter by the pump, there is going to be less PSI so with a high bypass pressure you're going to have reduced oil flow for a longer period of time.

 

Just came back from Advanced Auto. They are starting to stock and sell MANN filters. They dont have either the 950-4 or the 950-7 yet > I did order a Purolator L 40316 ....the other L 40107 isn't available at my local place ...he can't even order it so I may go to The Mann site and order a few.