Jims2001

The pressure went from 38 to 44 at idle and cruising speed. Is the increased pressure a good thing? And does the NAPA oil filter have less filtration abilty that a filter that does not increase pressure

AbsolutHank

I can't answer any of those questions. I do know that WIX makes the filters for NAPA and Carquest...maybe you could broaden your search questions to WIX for some more accurate answers

TopFuelTim

Just put a NAPA Gold filter on last Saturday. Saw no difference in oil pressure. Had a Mobil 1 filter on it.

Tim Glover

rws.1

My understanding is that pressure goes up as flow goes down and filtration goes up... ie a better filter increases back pressure.
Therefore it appears that your NAPA Filter has decreased flow and increased filtration. That is probably good for engine life, unless your race when maximizing flow is more important

jrose7004

I have noticed that oil pressure does go up for a while after a oil and filter change.

bb609

Mobil 1 bumps up the pressure too, at least it did on mine when I switched from stock.

427435

What oil (including viscosity) were you using before and after the change?? Was it dino or synthetic?

Cobraboy

Yes and no. A better filter will increase backpressure, but oil pressure in a car engine is measured downstream from the filter. So when you increase backpressure you are actually reducing main oil pressure. If you put in an empty filter cartridge you would get very high oil pressure, but no filtering.

bb609

So, what should one conclude regarding filtering of these "better" filters (Mobil 1 in my case) that do increase pressure?

Cobraboy

Good question. The only way a filter could filter "better" and give you increased oil pressure is if it has a lot more filtering area compared with a different filter. Since the casing is basically the same size, it's difficult to see how the filtering area could be much different. I've read a lot of reports of how people have cut open different oil filters and reported on the amount of filtering media in the filter. That doesn't really tell you much either. Think of it this way, would you rather have 2 square feet of window screen filtering your oil, or 1/2 square foot of fine cloth. The thickness of the filtering media also comes into play. These aren't filtering like passing something through a screen, it's more like passing it through a thick towel; the particles end up inside the media, not just on the outer surface.

I've never seen any good, scientific testing of oil filters (or air filters for that matter). Each manufacturer just says theirs are the best; "long life", "better filtering", "better engine protection", and other useless information. If anyone is aware of any testing, please let me know, I'd like to take a look at it.

Patman

I switched from a K&N oil filter to a Wix filter (which is an identical filter to NAPA Gold) on my last oil change (in the fall) and did not notice any change in oil pressure whatsoever. The K&N is generally regarded as one of the highest flowing filters too.

Oldvetter

I have been using DELCO Gold oil filters, they filter great but do not flow well. I recently changed to NAPA Gold (same filter as WIX), and my oil pressure increased. I think this shows increased flow.

Most people say that WIX filters are good filters. They have metal contruction and a large pleated filter. Only bad thing I have heard about them is that there is no rubber/silicone seal for the high-pressure bypass (just metal to metal), so it probably leaks a little all the time.

Dave68

One shouldn't generalize by saying that higher oil pressure equals better filtration. Some of the best coalescing filters out there can filter oil from airflow incredibly well, yet produce very minimal pressure drop.
By the same token, a really good oil filter will not only filter well, but produce little pressure drop. Back a few years ago, bobistheoilguy.com tested many oil filters and found a few to represent very good combinations of filtering ability and low pressure drop. Among them was the K&N filter. Patman has used this filter before more than one oil analysis and his results always showed that the filter was doing its job well.
Based upon his results and the bobistheoilguy.com tests, I have been using K&N oil filters in my C5 for quite a while now.

HawnHog

In this vein of oil filter questioning.... What about relocating the oil filter. I was thinking of moving it up into the engine compartment. The oil may be good for 10k miles, but changing out the filter a couple of times in that interval surely must be benificial to oil and engine life.

Comments...............

DJ

Patman

There is no bypass valve in the oil filters for our C5s, the bypass valve is built into the oil filter mount on our engine block.

They do have an antidrainback valve on them though, and they use the better silicone one (vs nitrile) which is more durable for hot/cold extremes.

Patman

There is no benefit at all to changing the oil filter partway through a 10k run, as even if you ran the filter to the full 10k it would not even be close to clogging up, unless your engine was severely sludged up or if you ran with no air filter on it.

Jims2001

One added question to my oil filter question. I know oil change intervals have been talked about before on here, but wandering if I should go by the oil % life left or how long I has been in there. It has been 2 years (2 summers) on the oil and filter and only 5000 miles. Should I have waited? I sure feel better changing it. Last oil change was AC filter and 5w30 Mobil 1.

Patman

2 years is perfectly safe, my mom doesn't drive all that much so on her last oil change in her 2001 VW Golf I let it go 2 full years before I changed her oil. It had 7600 miles on the oil, and when I got back the oil analysis results the oil still could've gone longer. She does a lot of short trips too, which usually causes the oil to degrade much faster.