...But do you really think that I have been doing damage to my engine by using these 'inferior' filters over the past years?
Let's face it, as far as Diesel engines go the 2L and even the 1KZ engines are pretty low-tech compared to todays standard. The tolerances on our Surf engines would be much larger than what they would be in say a new hilux/pajero/navara or euro diesel engine. Surely this also has something to do with how much particulate crap can be safely allowed to float around in the oil in our older engines. So should larger tolerance engines be able to cope with larger particles floating around in the oil before damage starts to occur???
So where do you draw the line as to what is acceptable and what isn't?
Perhaps a Ryco filter does filter the oil to an acceptable quality (to provide bare minimum engine wear) over a 5000km life cycle? In that case, and with regular oil and filter changes, would the expensive Toyota filter just be an overkill?
I'm not trying to start any arguments or defend any particular brand.... It's all just food for thought.
I'm sure we all have one common goal though.... We all want the best protection for our cars, with the minimal cost.
Well I do anyway
About doing damage etc...You or me have no way to know. There are heaps of variables at play. Air dust/ air filter, external temperature, sludge, type of fuel, condition of your ring cylinders and pistons, fuel pump too rich or too lean etc. A cheap filter just throws in one more variable. Just like you choose the best fuel to keep your engine clean, or a good shock and tyres to avoid accidents, you choose the best possible filter. As for the price of the Toyo filter, after buying them one by one for some time I decided to buy 10 and paid ... hum I think it was $25, Parra should know. So that beats the Ryco in my books.
As for your comments on tolerance, besides the very desirable one that is lacking so much this days, tolerance in diesel engine bearings crank and camshaft and moving parts in general varies not so much according to technological advances but with the number of revs, compression ratio and materials used. A diesel engine is a very low tech machine and has not changed much. Large marine or stationary diesel engines that go at 700 revs have larger bearings and the space between the white metal and the shaft is larger than the space between the shaft and metal in a Surf. This will be so with a brand new engine.
However this critical space that is necessary for the variations in size of the metal that expands and contracts with heat and that is also in direct proportion with the surface that is in contact, the larger the bearings the larger the critical space, does not mean that the larger engine is immune to friction caused by particles in the oil.
A 50 micron particle that escapes the crap filter will do the same damage to a bearing in a Sulzer then in a Toyota 3L. the difference is that there is more metal in the Sulzer and so the damage will be proportionally slower.
The space between bearing and shaft is measured without load. When the engine is running the forces on the shaft press it against the antifriction metal to a very fine film. This film's integrity is what keeps the two metals apart and depends on the quality of the oil and it's pressure. If a paticle comes between the shaft and the bearing, the oil film is not thick enough to keep both surfaces apart.
Stationary engines because of the fuel oil used, produce so much carbon particles that they have a much more sophisticated filtering system. Many have centrifuge in line for the oil,(Fiat for example) the fuel has a polishing system to keep it perfect all the time, and all have been installing secondary and tertiary oil by-pass filters costing thousands of dollars. Stationary and marine engines are so expensive to overhaul that they are fanatic about oil and filters and have it all too clear that dirty oil will destroy the engine.
The Toyota engine in question is not highly tolerant of particles in the oil, no engine is. It is the injectors who can have a larger tolerance to particles of tar in the fuel, the larger the injector, the larger the tolerance and that is why you can burn fuel oil or diesel 3 on ships that we can not use in a Surf...well...unless you get yourself a centrifuge...but that is another story.