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From: Built_Well on 11 Oct 2007 11:23 C. E. White wrote: > "Ashton Crusher" <demi(a)moore.net> wrote in message > news:lh9rg3pqb2bk0e1asl3mrem2ahds9c2i8m(a)4ax.com... > > On Tue, 09 Oct 2007 15:34:22 -0400, tnom(a)mucks.net wrote: > > > >> > >>>I refer folks to some of Dr. Haas' writings at this web page: > >>> > >>>http://ferrarichat.com/forum/faq.php?s=24e0725dc8adb142babe1958586368ba&faq=haas_articles#faq_motor_oil_basics > >> > >>There's more to oil selection than just this viscosity argument. > >> > >>The wider the range, 0w-50 compared to 10w-30,the more > >>solid particles are included in the formula. The particles under > >>heat, stress and age can settle out and contribute to forming > >>sludge. So it's best not to use an oil at a wider range than > >>you actually need > > > > > > That's a new one. What I've always heard is that the wider the > > range > > the longer the polymer chains that form the molecules. In the "old > > days" the polymer chains broke down from the heat and stress and > > when > > they broke into smaller chains the oil loses it's higher viscosity. > > Then you wind up with an oil that thins out way too much at high > > temps, that leads to low oil pressure, thin films, further > > breakdown, > > and then it all just goes to hell and sludge forms. > > Actually, the viscosity of motor oil usually increases with age and > usage - it becomes thicker, not thinner (assuming there is not a > problem with excessive blow-by). > > Ed ======== Ed, I think Ashton is talking about oil thinning as the engine is being used and the oil heats up. Oil, of course, thins as that happens. But I agree with you that over longer time frames--weeks and months--oil degrades from use, cold, etc. and the viscosity of the oil can increase/thicken from it original visc. I think you and he are just talking about different time frames and conditions, so you're both correct :-)
From: * on 15 Oct 2007 09:34 Comboverfish <comboverfish(a)yahoo.com> wrote in article <1192047885.644075.109040(a)r29g2000hsg.googlegroups.com>... > > You would be hard pressed to > find an oil that doesn't pass that minimum set of performance > standards. Peruse the motor oil aisle at your friendly local Wally-World. They are now marketing older, out-of-date API spec motor oil for "older" cars. This is NOT like the Pennzoil or Valvoline that is marketed as having been designed with additive packages for older cars. This stuff is, simply, out-of-date, non-current API spec oil.......
From: Steve on 15 Oct 2007 11:08 Mark A wrote: > "Steve" <no(a)spam.thanks> wrote in message > news:9eSdnYLR9JHNAZbanZ2dnUVZ_s3inZ2d(a)texas.net... > >>Or, maybe, you buy an engine that specifies a 0w30 oil..... :-) >> >>Personally I greeted the oddball 5w20 rating with a lot of skepticism, >>however a lot of OEMs do specify it. I'm sure that the main reason is to >>improve CAFE mileage performance, but its also a perfectly adequate >>lubricant for those engines. > > > Yes, I would use it if the manufacturer specified it. But this is a Toyota > forum, and to my knowledge that has not happened yet (and especially for the > specific models mentioned in this thread). Well, its actually an all-makes forum as well. Look where its being posted.
From: Steve on 15 Oct 2007 11:16 * wrote: > Comboverfish <comboverfish(a)yahoo.com> wrote in article > <1192047885.644075.109040(a)r29g2000hsg.googlegroups.com>... > >>You would be hard pressed to >>find an oil that doesn't pass that minimum set of performance >>standards. > > > > Peruse the motor oil aisle at your friendly local Wally-World. > > They are now marketing older, out-of-date API spec motor oil for "older" > cars. > > This is NOT like the Pennzoil or Valvoline that is marketed as having been > designed with additive packages for older cars. Which are snake-oil anyway... > This stuff is, simply, out-of-date, non-current API spec oil....... > > Which can actually make the oil better for certain applications, so long as it was a decent oil to start with (though most of the ones you're describing aren't). The current API specs require lower percentages of certain additives, particularly ZDDP, which are critical for engines with high-pressure sliding contact points- things like non-roller cam followers and gear drives of various types. That's why a lot of us with vintage cars have switched over to using diesel-spec oils (Shell Rotella, Mobil Delvac, Chevron Delo 400, etc.) instead of the latest "greatest" API spec'd gasoline engine oils. Even the diesel oils are having their percentages reduced, but not as quickly as the gasoline-engine spec oils.
From: Built_Well on 15 Oct 2007 16:09
Steve wrote: > * wrote: > >> Comboverfish <comboverfish(a)yahoo.com> wrote in article >> <1192047885.644075.109040(a)r29g2000hsg.googlegroups.com>... >> >>> You would be hard pressed to >>> find an oil that doesn't pass that minimum set of performance >>> standards. >> >> >> >> Peruse the motor oil aisle at your friendly local Wally-World. >> >> They are now marketing older, out-of-date API spec motor oil for "older" >> cars. >> >> This is NOT like the Pennzoil or Valvoline that is marketed as having >> been >> designed with additive packages for older cars. > > Which are snake-oil anyway... > >> This stuff is, simply, out-of-date, non-current API spec oil....... >> >> > > Which can actually make the oil better for certain applications, so long > as it was a decent oil to start with (though most of the ones you're > describing aren't). The current API specs require lower percentages of > certain additives, particularly ZDDP, which are critical for engines > with high-pressure sliding contact points- things like non-roller cam > followers and gear drives of various types. > > That's why a lot of us with vintage cars have switched over to using > diesel-spec oils (Shell Rotella, Mobil Delvac, Chevron Delo 400, etc.) > instead of the latest "greatest" API spec'd gasoline engine oils. Even > the diesel oils are having their percentages reduced, but not as quickly > as the gasoline-engine spec oils. ======== If you want lots of ZDDP, you might want to try the RLI Bio-Syn oils (RenewableLube.com). IIRC, their oil has about 2,000 PPM (parts per million) of phosphorous and zinc (engine wear protectant additives). Can't say for sure if this much would eventually harm your catalytic system. |