Anybody run one? I'm actually thinking about either a Frantz, which uses cheap Scott TP as a filtering media or a centrifuge. Both filter down to .5 micron or so. I could also go with an Amsoil bypass unit.

A lot of guys doing used oil analysis can run their drain intervals out a long damn way

Are those the same as years ago when Luberfiners were popular? I had one on a 56 Chevy. Worked great. I think I only ever changed the filter.

it's just as cheap in the long run to change the oil when it gets dirty or at the specified interval.
i never could see why some folks spend all that money trying to get extra mileage when all
you need to do is buy a good grade of API oil and a OEM or better filter and change it regularly.
and i never could figure those who try to save $1.00 or so and buy a filter that isn't worth 10 cents
when a good quality filter isn't that much more than a crap one.
and the only one who benefits from someone buying these "magic" engine oils is the salesman.
you can't go wrong changing it when it's dirty. cheaper than a new engine

Modern diesels are dirty about a 1/2 second after you start the engine with all the soot, quite a few people run bypass filters on diesels to filter some of that chit out.

yes, i understand that. my tractors have always done that and all diesels i've ever messed with.
all engines still need to have the oil changed at the specified intervals because of acids, condensation,
particulates.
i did think we were referring to gasoline engines when i posted. you could take the "when it gets dirty"
off and it would still apply to diesels.

Do you KNOW this, or are you ASSUMING this?

The only way to KNOW this is through oil analysis. It will tell you how much of the base is left, the viscosity, what your fuel dilution is, what your soot level is, and what your wear metal levels are.

Using a bypass filter, in combination with oil analysis through a reputable lab (NOT the bench top jokes), simply allows an engine owner to run the unit until the oil IS due for a change.

I know of a couple of semi owners that are now at a half MILLION miles without an oil change. They've added some oil during the oil filter changes and of course make-up oil, but the oil analysis shows the oil is still serviceable.

Just try to remember this: Filters are cheap...Engines are expensive.

What's your application? Oil intervals in modern diesels are already extended well past traditional levels. At the end of the day, engine oil is cheap.

1998 Dodge 2500 with a 12 valve Cummins

The bypass filters like the Frantz and the centrifuge filters will filter down to .5 micron. I'm going to go with a bypass filter for sure, just trying to figure out which one to go with.

I know guys that have gone over 50,000 miles on the same oil minus the make up oil from the filter changes and their oil samples are coming back really clean. TBN is still strong and the wear metals look great and the particle counts are sometimes as good or better than new oil

I'm leaning towards the Frantz but I'll have to change the TP filter every 2500-3000 miles or so but they're a dollar apiece so that's no big deal. They can also absorb moisture whereas the centrifuge can go for 12-15,000 miles before it needs to be cleaned.

I was hoping some of you guys had used them and had some feedback

http://www.cumminsforum.com/forum/g...antz-toilet-paper-bypass-oil-filter.html

Just curious, but how much does it cost to get your oil analysed by a professional lab?

I can perhaps understand the benefits of trying to stretch out an oil change on commercial/fleet vehicles, but would need to be convinced for private vehicles especially if you can do the oil and filter change yourself...

Edited to add, I like the idea of the bypass filter, but simply as extra protection for the diesel engine....

I pay $30 to have my analysis done, that's with Blackstone Lab

Had one done last oil change on the Pilot with 20,000 miles on Mobil 1 0W30 oil...

changed the filter every 6600 miles, using a Napa Gold Filter.

Blackstone recommended the next change at 22,500 and see how it looked then.

The TBN was still very usable.

Excellent filtration and a quart of make up oil help to keep the TBN high.

Found a centrifugal filter today that has potential. I need to see what kind of oil pressure I have before I make a decision

Never heard of the service being offered over here, although it might be something used by motorsport geeks.

I can change the oil in my vehicle for only a little more, so don't really see much gain except perhaps as a diagnostic tool....As I said, I can see it perhaps being a benefit to a large commercial/fleet operator where oil changes would cost substantially more.....

How often do you change your oil? What is the wear like inside your engine? Are you using the best oil for your vehicle? Is your air filter doing its job? If you can only answer the question about how often you change your oil you should consider a used oil analysis as it will help answer the other questions for you

The advantage of oil analysis isn't so you can save a couple bucks to extend the life of your oil. The advantage is to detect that parts are wearing abnormally before they fail.

That said, I was content to use conventional filters, change filters at 7500 miles and top off and change the Mobil 1 turbo diesel at 15,000 miles on my 5.9 cummins. At ~$70 for three gallons an oil change is pretty cheap all things considered.

That is correct, but wait! There's more! Oil analysis will also tell you you have a head gasket leak (evidence of coolant in the oil), an injector that's starting to fail (increased fuel dilution), an air filter housing that's not sealing (Si in the oil), etc, etc.

On an engine that is going to run for less than a couple of hundred thousand miles, don't bother. If you want to push the service life of the engine, catching things like fuel dilution early means saving your bearings and cylinder liners.

My 99 dodge cummins has 385K on it and runs perfectly. All it's life it's had the oil changed with Rotella T 15W-40 and a fleetguard stratopore oil filter every 7500 miles at 40-45 bucks an oil change, new fuel filter every 15K miles ($15), and a new air filter every 30K miles ($15). For all practical purposes you can't wear out one of these engines over the life of one truck body. It might be fun to experiement with bypass filters and oil analysis, but from a realistic standpoint you're wasting your money, just use good oil & filters at the recommended intervals and drive it.

When you spend as much time in rough, dusty country idling around additional filtration is never a waste of money especially if you can extend your drain intervals to 25,000 miles or more. It would be cheaper to replace a filter and a quart every 7500 miles wouldn't it? Wouldn't take long to pay for the additional filtration....

As Dutch pointed out...

I've had a head gasket leak reported via oil analysis twice in the last 30 years, but it allowed repairs to be done
before it killed the engine, antifreeze doesn't do the main bearings much good.... messes them up in short order.

I've also been thinking about a remote filter on the 4Runner...to run a 2 qt Ford Truck filter.

I run 20 to 25,000 mile drain intervals on that vehicle already....

and to answer Pete's question... you don't have to get it done every oil change....

anyone ever seen that old article from Popular Mechanics from back in the 70s, where an
engineer at Ford, ran a Lincoln he bought from the company after it had been used for some testing.

he ran the car 100,000 miles ( back then) with no oil changes, using Mobil ONE back when it was only
in 5 W 20... changed the filter every 5K.. and added as needed. then tore the engine down at 100K..

it showed little wear for an engine with a 100K on it...

the article is still floating around the internet.