New member. By-pass pressure question.

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Long time lurker, just decided to join. Lots of good info here and some great discussions.

My 2007 Focus (bought new), my wife’s EcoSport and my son’s Bronco all use Motorcraft FL-910S. The Focus has 176,000 miles and has run mostly on NAPA 5w20 full synthetic (Valvoline) because my best friend owns a NAPA store. I have always used FL-910S because it has a 14.5 psi bypass pressure. The NAPA (Wix) filter has a 8 psi and several other brands I investigated have an 8 to 10 relief pressure. I have used the Motorcraft for this reason. I have not seen much discussion here on the bypass pressure requirements. Why would Ford have their spec filter at 14.5 while other filter makers use a much lower pressure for this application?

I am a 5,000 mile oil and filter addict. I can do an oil change and filter for about $21 to $22 and I enjoy doing the maintenance, so why not? NAPA has the full synthetic on sale about every 2 to 3 months and the Motorcraft filter is $3.97 at Wally World. The Focus is the most trouble free car I have owned over the last 45+ years and stays exactly on the full mark over the 5,000 OCI.

Looking forward to insight on the pressure relief issue.
 

BlueOvalFitter

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Long time lurker, just decided to join. Lots of good info here and some great discussions.

My 2007 Focus (bought new), my wife’s EcoSport and my son’s Bronco all use Motorcraft FL-910S. The Focus has 176,000 miles and has run mostly on NAPA 5w20 full synthetic (Valvoline) because my best friend owns a NAPA store. I have always used FL-910S because it has a 14.5 psi bypass pressure. The NAPA (Wix) filter has a 8 psi and several other brands I investigated have an 8 to 10 relief pressure. I have used the Motorcraft for this reason. I have not seen much discussion here on the bypass pressure requirements. Why would Ford have their spec filter at 14.5 while other filter makers use a much lower pressure for this application?

I am a 5,000 mile oil and filter addict. I can do an oil change and filter for about $21 to $22 and I enjoy doing the maintenance, so why not? NAPA has the full synthetic on sale about every 2 to 3 months and the Motorcraft filter is $3.97 at Wally World. The Focus is the most trouble free car I have owned over the last 45+ years and stays exactly on the full mark over the 5,000 OCI.

Looking forward to insight on the pressure relief issue.
Welcome aboard!
There are quite a lot of members that are very knowledgeable here, and about your questions. They will be along soon. One member that comes to mind about your questions is Z06.
 

ZeeOSix

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I have not seen much discussion here on the bypass pressure requirements. Why would Ford have their spec filter at 14.5 while other filter makers use a much lower pressure for this application?
Because the filter bypass valve setting has a lot to do with the filter itself, and what the engineers decided to set it at in order to cover all the vehicles that filter can fit - meaning not all vehicles have the same oil pump or max oil pump flow rate. So they must cover all vehicles and design more the worse case scenario. If a filter has more flow resistance than the bypass valve will have to be set higher to prevent unwanted bypass valve opens.
 

dgc76

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Because the filter bypass valve setting has a lot to do with the filter itself, and what the engineers decided to set it at in order to cover all the vehicles that filter can fit - meaning not all vehicles have the same oil pump or max oil pump flow rate. So they must cover all vehicles and design more the worse case scenario. If a filter has more flow resistance than the bypass valve will have to be set higher to prevent unwanted bypass valve opens.
Thanks for the response. Does that mean Ford, at 14.5 psi, does not want it to bypass as easily as other engine manufacturers? Or that other filter manufacturers just recommend one fits the engine without regard to the engine manufacturer specs. Should I just continue the Motorcraft?
 

ZeeOSix

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Thanks for the response. Does that mean Ford, at 14.5 psi, does not want it to bypass as easily as other engine manufacturers? Or that other filter manufacturers just recommend one fits the engine without regard to the engine manufacturer specs. Should I just continue the Motorcraft?
Ford obviously designs oil filters more directed to their own vehicles ... that pretty much can be said for any OEM part. It may also be that a specific Motorcraft oil filter is called out on many Ford engines, so it must also be able to work on all of them and that could influence what the bypass valve is set to. Same basic thing with aftermarket filters. One filter model can fit dozens of different engines.

But if an aftermarket filter manufacturer specifies an oil filter for a specific vehicle then I'd put some trust in their engineers who designed and specified their oil filters.

The bypass setting is one of the most over thought things about oil filters. I wouldn't worry about using any filter that is specified for your vehicle by a main brand filter manufacturer.
 

dgc76

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Ford obviously designs oil filters more directed to their own vehicles ... that pretty much can be said for any OEM part. It may also be that a specific Motorcraft oil filter is called out on many Ford engines, so it must also be able to work on all of them and that could influence what the bypass valve is set to. Same basic thing with aftermarket filters. One filter model can fit dozens of different engines.

But if an aftermarket filter manufacturer specifies an oil filter for a specific vehicle then I'd put some trust in their engineers who designed and specified their oil filters.

The bypass setting is one of the most over thought things about oil filters. I wouldn't worry about using any filter that is specified for your vehicle by a main brand filter manufacturer.
Thanks. Next time NAPA has the Golds on sale, I will probably stock up. All three vehicles travel over 20,000 miles each year, we use 12 to 15 filters each year. I also have a pickup that uses FL-500S with a 8 psi and the NAPA filter is 8 psi, so I have used the Gold on it.
 

ZeeOSix

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Thanks. Next time NAPA has the Golds on sale, I will probably stock up. All three vehicles travel over 20,000 miles each year, we use 12 to 15 filters each year. I also have a pickup that uses FL-500S with a 8 psi and the NAPA filter is 8 psi, so I have used the Gold on it.
Actually, the FL-500S has a 17 PSI bypass valve per the product manager at Purolator (who makes Motorcraft oil filters).

 

dgc76

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Actually, the FL-500S has a 17 PSI bypass valve per the product manager at Purolator (who makes Motorcraft oil filters).

Interesting. Back when Ford spec’d the FL-500S for the Coyote 5.0, lots of debate on various Mustang forums on why as the FL-820S will fit the 5.0. General consensus was the bypass on the FL-500S was 8psi and the FL-820S was 16psi. Based on that, I went with the 8psi Gold filter for the F150. I did a couple of searches on the FL-500S today and found conflicting info at both 8psi and 15psi. I have always been a maintenance freak (still running a Craftsman Tecumseh push mower from 1980) by trying to use the recommended products. I guess I will just not worry about it on the filters any longer since I do not see folks having engine problems over various filter brands.
 

ZeeOSix

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Interesting. Back when Ford spec’d the FL-500S for the Coyote 5.0, lots of debate on various Mustang forums on why as the FL-820S will fit the 5.0. General consensus was the bypass on the FL-500S was 8psi and the FL-820S was 16psi. Based on that, I went with the 8psi Gold filter for the F150. I did a couple of searches on the FL-500S today and found conflicting info at both 8psi and 15psi. I have always been a maintenance freak (still running a Craftsman Tecumseh push mower from 1980) by trying to use the recommended products. I guess I will just not worry about it on the filters any longer since I do not see folks having engine problems over various filter brands.
Yes, there seems to be conflicting information on the FL-500S bypass valve setting, but that link I gave above is information from Purolator who makes the filter for Motorcraft. I'd take that as the definitive source.
 
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