Changing the oil without the filter?

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May 5, 2003
Southern DE
First, let me say that I never do this in any of my cars. It appears to me that the general consesus is to always change the filter, with some doing extended OCI's changing filters without the oil. Well, last year I got a new Kubota deisel tractor and the owners manual calls for changing the filter every other oil change. I still opt to change the filter every time. Just recently I got a Hustler ZTR mower with a Kawi engine and guess what.....owners manual says to change the filter every other oil change! Any guesses why they suggest this in garden equipment and not in autos?
Dealer installed filter on my Audi clearly says 2/yr 30,000km on it. Don't think I would leave it on with new oil though. Different philosophies make their way into different companies' maintenance recommendations. Some small engines do not even have a filter. [I dont know]
Honda has the same recommendation for their automobiles. I still change the filter every time, but I suppose that the engineers back at their factories may know more than we do, or not [Smile] . John
I've changed the oil without changing the filter when it comes to short change intervals. You could easily take an oil filter 7-8k miles, and change the oil every 3000 miles if needed. It might not be the perfect thing for some of the oil change purists, but I think it is safe enough. In my 2002 Honda owners manual it said you could change the oil filter every second oil change if you drive in normal driving conditions. So theoretically you could go up to 16,000 kms on the oil filter under warranty if you fall under the normal driving category. Of course most people would fall under the severe driving category in the owners manuals. But it proves that the oil filters are designed to last long periods of time if needed. I know nothing about mower engines though, but perhaps they are not overly-stressed items. dunno. Joey
Why do people put in a bypass system? For better filtration. Why on earth would you not change a full flow filter at every oil change, you aren't getting maximum filtration? For one thing is you aren't getting all the old oil out. Sorry, I think it's rediculous to put new oil in a vehicle that has an old filter, that contains old oil.
Additionally... Isn't the filter usually the least expensive part of the whole oil change? (Barring M1 and K&N Filters). Even when motorcraft 5w-20 is 1.40/qt, the filters are still a tiny tiny expense. But honestly...why not follow manufacturers recommendations and do UOA's after each change. Then do it the normal way with a filter change at each results.
I use a SuperTech filter, cost around $1.50.(I used a Frantz as my primary filt.) but, still, an average filter is about $2. Average quart of oil? What $2 also? You use 4-5 quarts on average, of oil, you only need one filter. People are always mentioning how "cheap insurance" it is to change your oil, well, it's even cheaper insurance to change your filter.
Originally posted by Doug: well, it's even cheaper insurance to change your filter.
I generally agree. But when the oil filter is hard to get to and it makes a difference in whether you do it yourself or take it to a shop, there can be a much bigger price differential.
s2000, You state that changing you oil filter could increase where due to dry starts. It's already been answer to just fill it up prior to install, but my point is, you state that dry starts can cause damage, you state you can't fill up the filter prior to install, because it's at an angle or almost upside down. Well, even on an installed filter, won't the oil run out anyways after you turn the vehicle off? That's means there is absolutely no diff. in changing your filter and causing a dry start vs. one that's already installed where the oil has drained out of. To each his own. [Patriot]
Using an effective anti-drainback-valve? There is definitely a difference in time between normal startup and startup after a filter change, even with a "half-fill" that is the best you can do on Honda 4-bangers. I think the oil filter lasts longer on newer cars. I would not suggest to everyone to skip the filter change, but if the owner's manual allows it, what documented reason do we have to disbelieve it's acceptability? That's my question.
Originally posted by Doug: s2000, Well, even on an installed filter, won't the oil run out anyways after you turn the vehicle off
I don't believe there are any facts of acceptibility. I'm sure it probably won't even cause any damage. I've heard that quite a few anti-drainbacks are crappy. Sure there are some good ones.
I ran two 12,000 mile OCIs recently, one with the filter changed half way the other no change. UOA was the same. Over the past few years I have come to the conclusion that full flow spin ons are pretty useless, other then adding 1/2 to 3/4 of a quart of new oil changing the filter half way accomplishes nothing IMO.
"...manual says to change the filter every other oil change! Any guesses why they suggest this in garden equipment and not in autos?" As others have mentioned, this shows up in some car manuals as well. The reason is simply to reduce necessary maintenance -- there's no need to change out a filter if its service life is well under half-used at the end of the first oil cycle. Makes sense. But like many folks, I can't bear to leave that half-qt of dirty oil in, so I change the filter each time.
someone asked why would anyone not change the filter at every oil change, i think they said it being cheap insurance or somthing like that. perhaps i should elaborate then at to why i only change it every 15,000 miles. for one thing, the owner manual for my car states that this is the normal oil filter change interval. for another, i am using an oversize filter which is about 4x the paper surface area of the stock size filter (and yes i did cut open a stock filter and my oversize filter and compare them) this oversize filter should be able to hold alot more "chunks" before it starts to go into bypass. the last time i changed the filter at 7500 miles, the filter was sparkling clean, although stained dark. it had no visual foreign particles in it, and my oil pressure didnt change. i figure if the manf says every 15K is ok, and i am using a 4x oversize filter, then why not run the filter change interval out to what it is intended to be? my car manual says to change the oil every 7500 miles, and the filter every 15,000 and thats exactly what i do. the mentality that some of you have about oil filter change intervals is as bad as the 3k/3 month oci mentality. some of you people dont mind extanding the oil change interval out to 15-30K miles, but yet you change the oil filter at every 3-4k miles? whats up with that? i figure everyone should ATLEAST change the filter when the manf recomends it. if youre car manf says to change the filter every 5K miles, then change it at 5k miles, if it says 7500, or 10K then change it at that interval. if it says at 3K, then change it every 3k! i dont advocate going longer than the manf's interval for oil or filters though. i dont really think changing the filter frequently is cheap insurance. do you change youre air filter every 3K miles too? how about youre tires? tires are more important than an oil filter because thay can make the difference between living and dying. why not change youre tires every 3K miles? the answer is because you do these things when they are in need of replacment. when does this short oil filter change interval become penny wise and dollar foolish? cheap insurance i think not, uesless insurance is probably more like it. most engines today have a bypass valve in them somwhere. if for some odd reason youre oil filter did start to clog up, it would start incremently bypassing the oil as needed. most of the oil will still keep on being filtered, but it will bypass whatever ammount it needs to keep the pressure differential in check. and the last and probably least important reason: if i drive 100K miles and change my filter every 15K, it would cost me about 30 bucks in oil filters assuming a price of $5 each. if i drove that distance changing my filter every 3K miles, it would be over 160 dollars. hey thats $130 dollars saved. not very significant i admit but that will sure pay for a 100K mile tune up of plugs rotor cap wires and a bottle of injector cleaner.
Apart from starting to think the way Spector is, have any of you considered that a filter filters more efficiently the more crud it collects ?? It doesn't matter what it is filtering, air, oil, water, the more they catch, the more efficient they are, until the pressure drop becomes so great across the filter that they eventually go into by-pass. Or just stop flowing. [Wink] [crushedcar] Just have a think about it [Big Grin] Rick.
tdi-rick - what you say does have have merit.. [Smile] I just don't like leaving any amount of used oil in. A full flow oil filter is just an emergency catch device....(I learned this from BOB [Big Grin] )... To each his own!
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