Using Larger Oil Filter?
 

Hello -

I was wondering about this post by CheapyBob :

Switched to Amsoil today.
My questions are :

1 - What do you think of using a larger oil filter for MPG?
2 - Are most oil filter connectors the same? If yes, then it's moslty just an issue of clearance.
3 - If it helps MPG, then how? Would it be because the area of the filter is larger or there is less pumping losses?
4 - Could the engine be hurt in some way?

Thanks,

CarloSW2

I'm not sure how many specs an oil filter has, but I know that you need one that has the same threads, and the same diameter of gasket, and most have a pressure relive valve, and I'm not sure if that changes much, I do know that our ford ranger oil filter can be used as the over sized filter for a geo metro if nothing else happens to be in the way, and on my civic vx I use a filter that is simply twice as long, the amsoil dealer that I buy from looked it up in some cross reference chart he had.
the way I see it, if you double the filter area, you might not cut your resistance in half, but you are going to be able to capture twice as much grit, and when your oil is cold and thick it's going to have twice as much area to push thru, so it should filter twice as fast, or pretty close, and that is why the relive valve is there, so if your oil is cold and thick, or the filter is clogged it can bypass the filter.

If you look at the base of the filter there is usually a code stamped on, such as 2C which is the type of base and fitting. If you can find a bigger filter with the same code as the one specced for your car, and if it fits in the space available you can use it. There are different threads and reaches and things for filters so be absolutely sure it fits on correctly, otherwise it will dump your oil on the highway and likely kill your motor.

I've always run the largest filter I can find as a matter of "it should catch more crap with less flow restriction". If it makes a BIG difference in F.E. it's probably because you're using 20W50 where you should be using 5W30 or something like that.

Gaining HP from a lower oil fill is likely to be engine specific, on some vehicles, the crank might be dipping into the oil at the full level and whipping it up into ropes and windage clouds that harm efficiency (hence the use of windage trays and crank scrapers) conversely overfilling can help some motors, because at higher RPMs they tend to suck the pan almost dry and start foaming the oil everywhere, which then leads to windage problems at both top and bottom of the motor if it doesn't actually hurt any bearings under high load (windage trays and scrapers help that too by making sure more stays in the pan)

Auto transmissions are also affected like this and some are better slightly overfull and some better underfull.

It might help some, but it's my understanding that it isn't size per se that matters.

What really matters (in a filter) is a combination of the filter's ability to filter, along with its ability to let the oil easily flow. Better oil flow rate can help FE, because it can lower parasitic losses on the engine. Likewise, cleaner oil is better for FE than "dirty oil", and the better the filtering ability (of the filter) the cleaner your oil will be.

Now it is true that all else being equal, a bigger filter should flow a little easier (more surface area for the oil to flow through), and also filter a little better (due to more filter media being in the can). So all else being equal, a bigger filter (that physically fits in the application) should be a little better.

But the thing is, frequently all else is NOT equal, as filters vary a huge amount in both the quality of their construction and the ability of their filter media to filter. So a quality smaller filter will win out over a bigger (less well constructed) filter almost every time!

NOTE:
Last I heard (and also what I use), the Amsoil EAO filters (and their fully synthetic filter media) are just about the best filters on the market these days, for their combination of filtering ability (both how fine of filtration they do, how much junk you can remove before they fill up) and their flow rate (which is amazingly good, especially in such a fine filter). And I'm not just saying that because I have an Amsoil dealership, but rather because I not only use that filter myself (and seen what it can do), I've also seen its filtering specs, as well as seen the results of independent tests done by some people over on the "Bob is the Oil Guy" forums.

NOTE:
If you really want the ultimate in filtering, combine a really good full flow filter (such as the already mentioned EAO filter), with what is know as a "bypass filter". A bypass filter, is a 2nd (doesn't replace the main) filter that is plumbed into your car, so that a small amount of oil is SLOWLY filtered very well (often down to 2 microns filtration, or even finer). The idea is, that very fine filtration often affects flow rate, and therefore it's hard to get both good flow (needed for the engine to get enough oil) and good filtration (needed to clean the oil of fine partials) in the same engine filter. Although some filters (the EAO probably being about the best on the market), make a good faith effort (by using better technology and better quality manufacturing) to do both with main engine filters, in the end you always have a trade-off between fine filtration and oil flow rate. So what a bypass filter does, is not worry about the flow rate issue, as it's designed to NOT be the primary filter in front of the engine, but rather to just supplement the main filtration by slowly doing a very good job of filtering/cleaning the oil in the crank-case. This results in TWO oil paths in the cars, the main (full flow) path as before, and a 2nd path that doesn't even try to meet the engine's oil flow needs, but instead just works to ultra-clean the oil.

And FWIW: Yes my CRX does use both a bypass filter and an EAO full flow filter, for just about the ultimate in keeping my oil clean and flowing. This, combined with the high quality synthetic oil I use, not only seems to help my FE, but also means that I can easily go 10 to 20 thousand miles between oil changes (because the synthetic oil breaks down so slowly, and the filter combination keeps the oil ultra clean)!

How about a couple of pictures, & a write up on the bypass filter? I've got a EAO waiting for my 2nd Auto-RX treatment to be done. Anything that will fit in a CRX should fit in a VX too.

I saw a post once(at priuschat IIRC) where somebody hooked their bypass filter up to a pump and tank. He would take the old oil from his vehicles, run them through this set up for awhile, have it tested, and, if still good, reuse it.

He went with this setup, because he couldn't mount the bypass filter in a Prius, and he had multiple vehicles.

I'll be happy to.

However, I don't know when I'll get around to that little project (the photos and write up), as I've been pretty busy with family (and to a lessor extent, work) issues lately...

I used to drive about 45k miles/ year in my diesel. The recommended oil change interval using a mandatory full synthetic only oil was 7,500 miles, that's a $25 oil and filter change every two months. I bought one of the less costly 'toilet tissue' filters (Gulf Coast Filters) in hopes of reducing the frequency and cost of the oil changes. Periodic analysis of the oil showed that the oil was still well within specifications after 55,000 miles with the one exception of a slowly diminishing TBN as the acid neutralizers were consumed. The loss of neutralizing capacity implied about a 75,000 mile oil life. Since my cam timing belt needs to be replaced each 60k miles and I have to have the car up on ramps for that, I decided to change my oil as frequently.

My job has since changed to one with a fixed commute, not on-the-road field service. The time interval between those former 60k mile intervals are now too long, so I did not install the by-pass filter on my current car when I did the engine swap. My present 5,000 mile annual use still means one oil change per year.

Anti-drainback valve, bypass pressure, gasket size, and thread pitch are the big things for you to look at. Most Hondas are 20mm by 1.5, Fords are ? by 16, and Mopar is the same I think. Go to wixfilters.com and do a search for your car. It will tell you the filter thread pitch, and other dimensions. then check out bobistheoilguy.com and the oil filter section and do a search for a bigger version of your filter.

I have a bypass filter that I will be setting up on my new car when I get it. The ARX may come before or after the install, haven’t decided yet.

Dust -

Thanks! I just went to WiX and got all the info I need

L4 1.9L 1901cc - WAGON/SW1/SW2
CarloSW2