Question on oil filter numbers
 

Decide to change the oil in my 98 Prelude this am. Go to Walmart and grab a jug of 5W30 Valvoline. At the Fram filter area, I can't find my car on the electronic gizmo or the book. Seems the year 2000 is the oldest they will go back.

I ask the guy sitting behind the desk in the auto area and he pulls it up and says "9688"
After changing the oil in that car prob 20 diff times, I said to him "I don't recall that number" He showed me on the screen and he had the right car and filter, so I bought that one.

Get home and put the car on the lift and when unscrewing the filter, I can see the number 3593. I took it off completely and laid it open end to open end with the other number filter....exactly the same. The length of the new one is about a quarter inch shorter, otherwise they are identical.

So, the new filter with new number is on the car and full of oil right now.

Why would a company change the number for a specific car?
I feel like I did something wrong to it....but I didn't?

It would not surprise me for something like that to happen.

The company is trying to save money.

I think the main bits are diameter/size of the "O-ring/gasket", size/threads on the nipple that the filter screws onto, and finally drain back valve. My guess is that there are probably 3-6 filters that would "fit" on a small block Chevy for instance. If the manufacturer can get away from making 6 filters where the main difference is the size of the housing and amount of filter element and only make 3 or even 1, then they'll go that route and probably save a ton of money.

I think these days a lot of filter manuf also make multiple "levels" of filters and those may have different numbers (but I'd expect them to usually have the same number with slightly different prefix or suffix letters).

Per the information listed below the things are identical other than the length. Maybe the bypass filter is more precise on the one and less precise on the other.
https://bobistheoilguy.com/forums/threads/xg9688-vs-xg3593a-for-hyundai-santa-fe.264211/

http://forums.pelicanparts.com/uploa...1758223146.jpg

^^^ Thanks for those numbers.....they compare very closely except for the height.

I guess it's not significant enough to worry about....although I'm sure I'll be looking at the garage floor every time I back it out for a while now.:)

And if you look at all of the numbers except the length, you can see they are all just rounded for 2 digits vs 3 digits, eg .13 vs .125, .202 vs .20. One of the devices has all of the dimensions defined as hundredths, but the other has all of the dimensions defined as thousandths. The only thing that doesn't look like rounding is the bypass where one shows as "between 9 and 15 psi" but the other specifically says 12psi. I would think that a specific pressure is probably better than a huge range.

^^^ I agree...I'm wondering if maybe some model car needs to have a slightly shorter filter for clearance and they made a new one that fits both. (the age of my Prelude probably doesn't justify a separate type for each)

Exactly. That's my bet. No need to make 2 filters that are 98% the identical.

On a vaguely related note.

Lake Speed Jr who is running the "speediagnostix" used oil analysis business, is a tribologist, used to develop oil for Joe Gibbs Racing, etc... (he knows oil and oil related stuff) has said that most of the oil filters these days that are "premium" and rated to last for 10k or 15k or some high mileage are allow more/larger particles through the filter medium so that they don't clog up if run for lots and lots of miles. So he has advised that if you change your oil at normal intervals (3-5k miles) you're probably better off using one of the cheaper lines of the same brand of oil filter.

I know back in the day, there were 2 models of oil filter that you could buy that would fit (assuming nothing got in the way) a small block chevy (pre LSx SBC).

Regular sized SBC oil filter
https://www.moroso.com/media/catalog...459new_web.jpg

Tall sized SBC oil filter
https://www.moroso.com/media/catalog.../22461_web.jpg

I would not care if the oil filter lost 0.31" of length, but if i could get/fit one that was 2-3" longer, then I would be willing to do that. The filter on my wife's Outback is very small. I wish it was another couple of inches longer, and I think it's got enough space/clearance to be longer.

^^^ There's probably one made somewhere that would fit that....might be hard to find it though.


Ever since I started driving, I've used Fram and never had a problem. The two 911's I've owned, I used Mahle filters because of the name.

The Prelude has lived a good portion of it's life with nitrous boosting the hp. The Fram filters have done the job....doesn't use or drip any oil at 118K.

.

I'd meant to include this in my previous post, but got distracted. I have no idea how it would apply specifically to your car or any car other than the exact filters mentioned. I have no idea if the filter specs match all filters of a particular category or if the specs are particular to individual models. I suspect it could be a mix of both.

I find it interesting that they essentially only use the Napa Gold but do not use the Napa Platinum which I'm sure Napa markets as a better filter, but clearly, LN Eng doesn't think so.

I'm still using the Mahle cartridge filters in my Boxster so far.