I replaced my cannister type oil filter on my 1966 327 a few years ago. It has been a great upgrade.

The original cannister used an AC PF-141 cartridge.
The replacement screw-on was an AC PF-25.
This was the common recommendation by Ecklers, Corvette America, etc.

So now, it's time for a new filter and I am out of stock.
Went to the Chevy dealer only to find out that the AC PF-25 has been replaced now by EITHER the PF-454 or PF-1218 - my choice. I asked to see BOTH of them. Good thing. <results below>

Next I went to O'Reilly's and purchased the Fram replacement PH-30.

Here's what I found:

Replaceable Filter Lengths

• AC PF-25 (4 1/4") ORIGINAL REPLACEMENT
• PF-1218 (4 1/4") New Replacement
• Fram PH-30 (3 3/4") Cross-reference match
• PF-454 (3") Alternate new replacement-not shown

So... Which one would you use? Oh, one last thing, as you can see by the photo the original screw-on type, which was WHITE, was replaced by the new ACDelco BLUE, and of course, Fram has always been ORANGE.



PF-141 ******* *AC PF-25 ********* ACDelco PF-1218 ******** Fram PH-30

Again, which one would you use? And I've got to ask "Does length make a difference?"

--Bill

I would use the PF 1218....actually all of the would work OK.
I have had GM mini-vans for years with 3.8, 3.4 and 3.5 V-6 engines. They call for an AC-47 filter which is quite short. I use the AC-51 which is for a small block 8 cyl and is about 2" longer. The length is the only difference and the 47 has more capacity....for the same price.

The 1218 probably has a better check valve in it. I will be calling on my Chevrolet dealer tomorrow and will ask.

I am a stock kind of guy (a rarity these days) and never had a problem with a canister filter or filtration problems. AC Delco is always replacing numbers and combining applications, but the best filter on the market I found is the Fram.

I'm with John, I'm down to one Delco from a case I bought years ago, for some reason I'm holding on to that one.... I've used Fram but have been using Wix filter in my canister the past 2 oil changes

If you search the oil and filter sites you can find a lot of negative things about Fram filters.
I have been using Mobil ! filters and run them for two oil changes or 6000 miles.

I am sure you will but I tend to think you will find more negative things about using the same filter for two changes..... sort of like taking a shower and putting on dirty socks (or worse) to me.

If I were to run 5000-6000 between oil changes I would replace the filter with each change. I change oil every 3000 miles, use synthetic oil which is far from black at 3000 miles. I have cut the filters open only to find nothing trapped on the filter media. As far as the pint of dirty oil in each filter every other change....100 years from now no one will ever know the diffeerence. My engines always stay spotlessly clean when looking in the oil filler opening.

The AC 1218 has a better check valve so as to keep the filter from draining when the engine is shut off on applications where the filter lays sideways.

Thanks Gene. My filter is mounted in the upright position, so I assume that the check valve doesn't make any difference for my application. (?)

Since there appears to be no real "evidence" as to whether FRAM or AC is better, I'm going to assume that they are functionally equivalent. Also since I change my filter EVERY SINGLE time that I change oil (at 5,000 miles), I suspect that any minor filter variances won't have any effect. (That's a lot of "assumptions".)


Part of my original question, which nobody tackled, is I was wondering how Chevrolet could recommend two filters as being "the same replacement" when one of them is 4 1/4 inches tall, and the other is 3 inches tall. I can't believe that they have the exact same filtering capabilities. And since the size or the original replacement was 4 1/4, why would I want to replace it with the shorter one?

Correct, The check valve has no effect on your up-right filter.
Filter size. Go back to 1956 and 1957. Look how big that element was. Was shortened about an 1 1/2 inch for 1958. The next flter the
ac25 - was a full sized throw-away filter. Then came the little filters tha all cars use today. I call them the Tea Cup sized filters. I guess you have to go along with smaller is better.
The most modern GM engines have an element that fits inside a reusable cover. When you remove the filter you can actually see how dirty it is.
When they went to the 25 in 1968 it was actually a 35 and it hung down too low and could get knocked off by road debris. So the shorter AC25 was made.
I would say the main thing is to stay with a name brand filter. Most filter makers today have two or three lines of filters at different price levels.

"Tea Cup size".... good one.

I'm going to stay with the bigger size. Again, I'm "assuming" that it has more filtering inside. ((And I will know shortly, because I'm going to cut a couple of them open.))

One last post -- the Fram was $4, the "new" AC was $7 and the previous AC was $12. So the AC (from the dealer) is now only $3 higher. Not significant any more.

Good discussion. Thanks

--Bill B

At my previous employer we had a project to develop a better oil filter. In our testing we cut apart a TON of used filters. Only on one vehicle in the test fleet did we find anything significant in the filters. Its engine cratered later. We only had a few high mileage engines in the fleet as the filters were designed to slowly add more protective additives over their life so we didn't want the complication of adding fresh oil. FYI, It was a pain to try to compensate for the fresh oil given we had several brands in the test fleet.

My advise is use any good quality oil filter you want. The life of the filter is more determined by the condition of the engine and construction of the filter than crap in the oil. If you have a lot of blow-by or short trips then the filter will remove the sludge formed and can plug up. Changing every oil change is overkill but considered cheap insurance by many. Yes I change filters with oil changes. Have a bunch of old Chevys that don't have filters too.

Like other automotive items filer technology has improved to the point that most any filter will be adequate. Also the major manufactures copy each other so much when improvements are made that there is little difference in the products. One of the differences affecting price is the filter media. While the higher priced premium filters may be somewhat longer lasting I think its a waste of $$ for the little use they get on our antiques. One of the benefits may be that while in use they will last a long time without filter media breakdown for those that don't change their filters on at least an annual basis. I would be more concerned with the air cleaner filter as many are glued or bonded and that glue or bonding can deteriorate over time whether the filter is installed or not. That NOS air filter element at a bargain price just might not be a bargain.

There are several oil filter "tests" om YouTube. Go there and search oil filters. Don't believe everythig you see though.

Dang, this is good stuff....

Gene,
Are you suggesting that I go look at the YouTube videos, but "filter" some of the comments?



The end.


--Bill B