I gotta say, that Bob seems to make salient points when discussing the Toyota sludge problem. Monarch, just about everybody would agree that Toyota makes generally superior products, but why do you assume that just because there are lots of hi-mileage Toyotas running around LA, that they absolutely could not have marketed a design that is less effective than what they intended, or that consumers are used to?
There is a scientific theory called 'The Law of Unintended Circumstances', and it appears that maybe Toyota got 'caught' in this. The reduction of additives from SH to SJ, the extended drain intervals(which we all know is just advertising hype),operating heat, mechanical effects of the engine design and unique and specific driving conditions have all OBVIOUSLY contributed to those particular engines having the unintended circumstance of building excess sludge. Bob obviously talks like he knows what he's talkin' about, and he seems to have the facts(a lot of them!) to back up his claims. Plus, when you add up all those facts, they only make sense! Monarch, you on the other hand seem hell-bent on trying to convince everybody that your theory is true based not on facts or supporting evidence, but on the opinions of Toyota 'techs'(do you consider dealership personell 'techs'?), specious, simplistic conclusions and single-cause reactions. This particular problem with sludging is obviuosly caused by a myriad of circumstances and driving conditions. There is not, and could not possibly be one singular factor that could lead to this problem in all these situations. Like your insistence on the faulty PVC system.(which by the way, is PCV, not PVC. One is an automotive emissions device, and the other is a plastic pipe.)If the PCV system was completely disconnected, it is still not possible for the non-functioning PCV system to cause such a precipitous drop in viscosity. The cause is obviuosly to be found, at least partly elsewhere. Yet, for some reason you keep singin' the blues about the 'faulty PVC systems'. I don't mean to stay up here on my soap box, but when I someone trying thier best NOT to learn something, and continually claiming the same disproven theories, it kind' gets me going.