Lug_Nut, what oil were you using with your TP bypass? Also, what kind of TP...I can only imagine TP disintegrating too easily and getting into the oil.
Mobil1 0w-40 "european car formula" as this was the only full synthetic specifically marked as meeting the VW 505.00 specification required for the early TDI short of going to the VW dealer.
The rolled paper I found to work the best for this purpose is the same stuff you don't want to use for its intended purpose: Thin, single-ply, densely wound, 1200 sheet if you could find it. For travel I tended to stay at any numbered hotel (Motel6, Super8 ). These low priced hotels had just what I wanted so I'd scoff the spare roll from the back of the toilet tank at check-out.
The bypass filter case was tapered such that the bottom of the roll was very tightly packed from OD towards the core. The oil flow path was across the "width" of the roll from the less dense side to the greater, thus using all the roll with finer and finer filtration as the oil passed through.
The rolls retained their integrity extremely well and did not become a cellulose jelly.
I'll see if I still have some images and will link to them.
It turned out that I was able to stretch my oil change interval to 60k miles ('96 VW diesel, Mobil1 0w-40). The oil was still good, so why stop at 60k? Because that is the timing belt replacement interval and I had to get under the car for that, so why not?
Did you have a Total Base Number analysis performed?
How did the M1 hold up?
FWLIW, at the moment I'm comfortable running a good Syn to 10K in my Accord. The car is easy on oil, so I don't think 15k would be pushing it too badly, but before going any further I want to get the oil analyzed. I've got one of those Blackstone kits waiting; at 10K, I'm going to draw a sample and send it away to the lab.
castrol has a new oil (castrol edge i think) that supposedly gets 25,000km or 1 year between changes....its a full synthetic but i'm still scaird. 25,000km oil change....hold me i'm afraid!
considering that their syntec is a lot cheaper (that edge crap was around $40 CAN a jug!!!) i'll stick with that stuff.
The oil company's want you to be scared. I run mobil1 and change around 8-10,000 miles. I put 50,000 so far, runs like new and doesn't need need oil added. between changes. Not all than impressive for 3k changes and 10w30. But I run 5w20!
Amsoil makes high zinc, high phosphorous oils still for flat tappets. But newer specificaitons have been cutting back these levels as per mandate. Their current tech Signature Series oil is 24,000/40,000 kms for severe/normal service. (15,000, 25,000 miles). They have certain criterion for determining service conditions. It's mostly common sense. A nice new engine that is still tight at the rings can go a very, very long time on this oil, far past one year and 25,000 miles, but Amsoil has to assume worst case scenario when making these types of guarantees. Oil analysis almost always shows oil to be good for longer, unless the engine is old and beat-up, or people have cheaped out and put some crapy filter on that is not made to go that far. (Amsoil also has top quality filters that match the oil drains...and good filtration is just as imporant as good oil.) I do oil analysis for customers on a semi-regular basis, and Amsoil simply shines. Not saying there's nothing else good out there...but in my decade of experience with it nothing touches Amsoil; I put in in every vehicle and every application I can find, and it saves equipment, money and fuel. And yes, I sell it and yes I'm biased so I'll just get that out of the way right here. But I sell it b/c my work dried up and I had had so many years of very good experience with it, I feel good about selling a quality product. Not like some used vacuum cleaner salespeople who have come around! lol.
I now have 52k on the Synlube 5w50 that I put in at 3800 miles with a filter change at 36k ... seems to working great still only added maybe a cup of their "add-oil" which replenishes the sacrificial part of the Synlube. I basically add a small amount (60cc) every few months just to keep it replenished but the level really hasn't dropped much from burning.
I don't know what you drive. With 52,000 miles on the oil you might want to seriously consider changing it or getting an oil analysis, one that shows all the pertinent info, such as TBN, Viscosity @ 100 Celcius, and wear metals, among other things. A lot can happen in 52,000 miles, and you are looking for trouble with this, IMHO.
There are limits to everything, even a good synthetic lube. I've never known a better quality oil than Amsoil with their 25,000 mile guarantee, but even if Synlube were a high quality synthetic there is still a useful life for this fluid, and I'm thinking it's looong overdue for a change. If the car was new when you started (3800 miles) that will help you a lot (as compared to trying this in an older, more worn vehicle), but why risk an engine?
Secondly, if your vehicle is quite new it will not be specing oil anywhere near as thick as a 50 weight oil. The thickest for normal gasoline cars these days (excepting euro vehicles, many of which still call for a 40 weight) is a 30 weight, with many vehicles specing a 20 weight oil for over a decade already. Vehicles are engineered with oil viscosities in mind, and if you are 2, possibly 3 grades thicker than OEM specs you are also looking for trouble in this regard too. Even if there are no mechanical problems (yet) per se, at the very least you will be using a whole lot more fuel up with every tank of gas than you need to.
Lastly, oil consumption alone is hardly the way to determine how good your oil is still. Neither is how dark the oil is, or how "slippery" it feels in your fingers, etc. Oil analysis is the only way to take the guesswork out of it. There are a lot of variables in oil life & condition, and with an oil that thick in a new car it better not burn any!! The fact you still have to top it off at all says something not good to me.
I checked out SynLube's website. Sorry, it does not impress, nor does it's product line or claims. One claim they make on their website for using their product is: No Oil Changes in most applications during the “Useful Life” of the vehicle or equipment. They do not define which applications fall under "most applications", nor do they define what the "useful life" of a vehicle is. Very ambiguoius and highly dubious. Moreover, a super broad viscosity spread of 5W-50 is also problematic in other ways. Smells like something you should steer clear of. At the very least use a recognized brand name synthetic and follow the proper drain interval recommendations.