Originally Posted By: Johnny
AdRock, I mean this to be constructive, not criticizing.
No problem. I'm all for constructive criticism. I'm not a chemist and have not ventured deeply into the workings of motor oil. My knowledge comes from what I've seen. I worked as a mechanic for quite a while and did work on a lot of fleet taxi's so I've seen how different oils hold up on those cars that get tons of hard miles put on them. There's still plenty to learn in the oil dept. and it's always changing. I quit working as a mechanic by profession back in 2000 because the money just wasn't good enough anymore. I do still however keep all my certs up to date and am regularly working on one car or another. Mostly to get ready for racing. The UOA's are something I've never done on an oil and part of the reason I signed up here is to learn. So if I'm way off base on something then I have no problem with someone correcting me and giving me the straight poop on the deal. I don't know everything and will never claim that I do.
The first thing you need to do is get over the 3K oil change. I know it's hard to do as that is the way I was raised and I did it for many years, with both conventional oil and synthetics. It is the 21st century, half way through 2009, and there is not an API approved oil on the planet that cannot do 5K oil changes.
The last 2 oil changes I did on my car and the wifes were at 4k. So I'm slowly working myself into getting used to the longer OCI's. I can however tell the difference in how my car runs & feels after 3 or 4k. Engine noise increases and performance goes down slightly.
Now, if you are going to use a quality synthetic like Amsoil this is what I would do. Get the Amsoil of your choice and get the Amsoil EaO filter for your applications, change the oil on both vehicles and don't worry about it for at least 7.5K. I know it will be hard, but it can be done.
Now, as for as filtering used oil. You might run it through a fine screen or a paper filter, and you might filter out some dirt particles, but you cannot filter out the contaminants produced from combustion process. And even at 3K those contaminants are in there.
That was kind of the basis for one of my above questions though. I know that after 3k those contaminants are in there. If those contaminants left in there cause the oil not to be good enough to put into another vehicle for the second 3k miles with a new filter then why wouold it be good to leave it in my car over that 3k with the same filter? The answer to this question is what no one has answered yet.
I guess the first question we should have asked is what year models do you and your wife drive, what is the mileage on both vehicles, and what kind of conditions are these cars driven, i.e. mostly highway, city, etc.
My vehicle is a 2002 Mustang GT 4.6 NA. 5spd TR3650 with 89k miles on it.
Mods include:
Diablo tune,
JLT short ram intake
stock throttle body with Pro Products aftermarket plenum
energy suspension motor & trans mounts
Centerforce dual friction clutch,
aluminum flywheel,
Steeda quadrant & cable adjuster
Ford Racing aluminum driveshaft,
Steeda tri ax [censored]
stock 8.8 rear end housing with a TA girdle, Superior 31 pline axles, and an F150 31 spline Traklok with 4.10 gears
Mac Pro Chamber off road mid pipe w/ mil eliminators
Flowmaster mufflers welded intot he stock catback
Vogtland springs
Tokico shocks & struts
Maximum Motorsports CC plates
Granatelli upper & lower rear control arms
Motor oil started with Amsoil 5w30 when I bought it with 16k on it. The price on Amsoil went up quite a bit so I switched to Mobil1 5w30 a few years ago, always with a FL820S filter changed every 3k miles. Tranny fluid is Mobil1 Mercon V changed every 25-30k. Rear diff is Mobil1 75-140 and changed when I do the tranny. A bottle of Chemtool is put in the gas tank and some Seafoam run through the intake about once a year. Fuel filter is changed every 6 months. Motorcraft Copper plugs in the engine pulled, checked and regapped every 15k. Throttle body checked & cleaned(if needed) every other oil change. Same with the PCV valve since the 4.6's have a bad habit of sucking a lot of oil throught the PCV.
I run the car hard in everyday driving and go to the track a fair amount. I'm not easy on this car at all so I make sure I'm on top of things. I know any anomoly, squeak, engine noise, etc. that is not normal for this car.
My wifes car is a bone stock 2003 Honda Accord 2.3 4cyl with 55k on it. I have been running Motorcraft blend in it and changing it every 4k with a Mobil1 filter. Since it just passed 50k it's about to get a trans flush. Besides that I do maintenence on it in regular intervals. My wife is not hard on the car at all so normal maintenance is fine and the car is in tip top shape.
Good luck
Something to note - there are companies that make bypass filters that use paper towels and toilet paper (depending on size of filter housing) - I think one of them is GulfCoast filters. I've read that both toilet paper and papers towels will filter down to a very low micron level (much lower than any full flow filter) - I would be hesitant to use toilet paper in a home filter setup due to possible disentegrating the paper (but ?).
But anyway, I've thougt about a home setup - perhaps dropping the oil into a plastic pail, letting it flow thru a screen mesh (tea) sieve, with several layers of paper towels (perhaps with inbetween layers of quality toilet paper) on the sieve. Would need to be in a dust free (as possible) environment.
Also could use a fluid extractor (hand pump with hose that goes down the dipstick hole) to get the oil out (instead of draining). Then it could be pumped out whenever wanted and put thru the filter without doing the whole oil drain thing.
But at the end of the day, I'm not sure if a single pass thru this system would give lower insolubles - but it seems it would.
