Gearhead Jim

Looking at old threads here, and some of the info from other sourcs, I find different comments about the two filters. No one seems to dispute that the UPF48R has a higher burst strength. But other characteristics get different comments. For example, some claim:

1. The UPF filters smaller particles, and that's good.
or
2. The UPF filters smaller particles but it makes no difference, the standard PF removes anything that is big enough to cause wear.
or
3. The UPF filters smaller particles, which can be good when the oil is hot but not so good when the oil is cold because it can restrict oil flow or cause the filter to bypass.
or
4. The UPF doesn't filter any better than the PF, GM just brags about it more.

Of course, GM seems to change the design/manufacturer of their filters from time to time, so that makes the comparisons even more difficult.

For those who can post comments about the filters, please post links so the rest of us can save them for the next discussion! Thanks.

KneeDragr

I'd stick with what your owners manual says.

bosco 08

Why do car owners continue to try to outthink the people who designed the car in the first place?

Gearhead Jim

If you owned an oil-gulping 2001 with the "improved" ring design, or had a loose/disintegrating harmonic balancer, or a 2006 where the OLI reset when you used the Elapsed Time function, you'd understand.

GM engineers are very good, but not perfect.

If one can extend the life of the engine simply by spending a couple of bucks more for the oil filter, that's a good deal. But if the "better" filter can cause other problems, then I want to stay away from it. Who wouldn't want to do that?

JoesC5

UPF-48R uses the synthetic filtering media, same as the Mobile1 and K&N premium filters. If there was a problem with the synthetic media restricting oil flow, then I doubt if GM would install it on their $125,000 ZR1 and warrant it for 100,000 miles.

Gearhead Jim

The dry sump cars run higher oil pressure, so that might eliminate a problem.

Or maybe the higher oil pressure would cause problems with the ordinary media, so they use the synthetic.

Maybe...

JoesC5

Z06 and ZR1 have 100 psi gages(and ~22,000 Z06's were built with PF48 oil filters). LS3's(both wet and dry sump) have 80 psi gages.

Gearhead Jim

Looking at the 2013 Owner Manual, they show the PF48 for the wet sump LS3 and the UPF48R for all the others. If the UPF was really a good idea for the wet sumps, they could certainly have listed that as an alternate or even as the only filter for replacements. But they didn't.

An oversight, or do they know something we don't?

GOLD72

During the C5 Generation, GM/AC Delco superseded the PF44 with the PF46. It was my understanding at that time the only change was upgrading the internal media from cellulose to synthetic. So I assume the standard PF48 also has synthetic media when eventually it became the standard C6 Gen filter in MY2007.

AORoads

Guessing here, but it could be they're both synthetics. But as Jim suggests above, my guess is maybe they're differently packed with synthetic material as in, one with more, and one with less, depending on oil pressure. Truly just a guess on my part.

And as Jim noted above, it's odd that the UPF wouldn't be listed as an alternative filter for the wetsump. But I can't draw any conclusion for that non-listing of the filter.

GSRANDY

The AC DELCO ULTRA GUARD UPF48R is one great oil filter based upon it's filtration capability rating:

98% efficiency rating.

8-10 micron filtration level rating.

Regards,

GSRANDY

JoesC5

They know that the money saved over a year, across the full line of trucks and cars with LS engines adds up, and the PF48 is cheaper then the UPF48R. No need to install a premium filter on millions of new vehicles when the regular filter is more then adequate.

JoesC5

Why should they list an alternate when the spec'd filter does the job?

JoesC5

from ACDelco's site on Duraguard filters.

•98 percent single-pass filtering efficiency at 25-30 microns for excellent filtering capabilities

•Patented cellulose media traps particles 1/3 the width of a human hair to help provide a clean supply of oil to engine components

•Thermosetting adhesive seals hold filtering media in place for consistent, dependable filtration

•Designed with five times greater burst strength than most engine oil operating pressures after the oil reaches operating temperatures

•Application coverage for 97 percent of all cars, light-duty trucks and sport utility vehicles, both foreign and domestic

Notice that they use "cellulose", not synthetic filtering media.

Gearhead Jim

Going back to my original post, which of the 4 situations do you think applies here?

jbomx363

I'll go with No. 2.

GM'er

I like #1

Anyone every seen the hair demo on a main bearing?

On an engine rebuild, I saw all of the rod and main bearings installed with new bearings, and the caps torqued down. The engine could be spun over by hand with a rachet on the the front of the crank. Then a main bearing cap was removed, and a single hair was placed accross the bearing, the cap was reinstalled and torqued down. The engine was locked up solid and could not be rotated. Crazy.

AORoads

so muc h for their both being synthetic filter elements.

Gearhead Jim

This afternoon I phoned Blackstone Labs, who have done my previous oil analysis work. I explained the difference between the filtering media and filtering ability of the two filters. Then I asked if they thought the UPF would produce longer engine life.

The guy said they don't specifically test oil filters, and usually don't know what filter is installed on an engine. But in a few cases, someone has sent in a sample and advised that he had gone from using a "standard" filter to a premium filter that filters down to less than 10 microns. When they compare the analysis results with the premium filter and previous results with the standard filter, the wear metal differences are so small as to be within the normal variation you get from one run to another.

But still, GM must be using that small micron synthetic media for a reason...

bosco 08

Maybe the difference is for a longer period between oil changes.