Automakers Lengthen Oil Change Intervals
in [Drive]
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From: clare at on 29 Mar 2007 20:31 On Thu, 29 Mar 2007 07:37:51 -0500, tetraethylleadREMOVETHIS(a)yahoo.com (Brent P) wrote: >In article <1175171148_8125(a)sp6iad.superfeed.net>, jim wrote: >> >> >> Brent P wrote: >>> >>> In article <5e7m03h7jbpfh502qbt6nepp7ic8rsh94e(a)4ax.com>, clare at snyder.on.ca wrote: >>> >>> > Minimum 20 minutes to get the oil to full operating temperature, and >>> > then about another 10 minutes for every day of short run cold morning, >>> >>> <snip> >>> >>> When your coolant has reached OT and the thermostat is open, the oil has >>> reached operating temperature some time before that. It's basic heat >>> transfer. If it had not, the coolant and engine block would still be >>> warming the oil and the Tstat would remain close. >> >> The thermostat does not remain closed until the engine is warmed up it >> opens proportionate to the coolant temperature. Ideally it never opens >> all the way. In your world, perhaps. In the real world, the thermostat often opens all the way, and the oil temperature generally lags the engine coolant temperature, and often excedes the coolant temperature inside the engine. It is cooled TO the coolant temperature by the oil cooler (if so equipped) It is also PRE HEATED to coolant temperature when it is cold, when equipped with an oil to glycol cooler. Have you ever had a vehicle with an oil temperature guage installed? How about more than one gauge? I've had vehicles which consistently ran 320+ F in the sump, and which took significantly longer to reach 190F than the coolant did. Cars in question did not have oil coolers. >Thanks mr. usenet nit-pick. I think everyone knows what was meant and how >a thermostat works, I didn't feel the need to write an entire paragraph >about it and go into a HS calculus lesson on limits either. > -- Posted via a free Usenet account from http://www.teranews.com
From: clare at on 29 Mar 2007 20:21 On Wed, 28 Mar 2007 23:02:50 -0500, tetraethylleadREMOVETHIS(a)yahoo.com (Brent P) wrote: >In article <pb7m031m123p78ksrcc3qf7svpki52rqor(a)4ax.com>, clare at snyder.on.ca wrote: >> On Wed, 28 Mar 2007 16:05:37 -0500, tetraethylleadREMOVETHIS(a)yahoo.com >> (Brent P) wrote: >> >>>In article <460ad725$0$27206$742ec2ed(a)news.sonic.net>, SMS wrote: >>>> Steve Barker wrote: >>>>> I'm a regular guy (retired) with 4 vehicles that always have, and always >>>>> will, get 3k oil changes on straight 30 weight oil. >>> >>>> This will increase the engine wear at start-up, though if you're in a >>>> hot climate it won't be too bad. Just make sure that it's a detergent >>>> SAE 30, not non-detergent, as both are available. >>> >>>There are some engines with small oil passages where it's probably not a >>>good idea at all. > >> Not an engine built that can't run straight 30 if the temps don't drop >> below something like 55-60F. > >Funny how the same people who demand that 3,000 mile oil changes are >needed just to prevent engine damage feel that changing oil weight from >recommended is just fine and dandy. Afterall, the engine was extensively >tested by the manufacturer with the weight of oil specified.... and you >just 'know' what will work 'better' in it without so much as engineering >drawings of it. > >I'll stick with the recommended weight oil, as I know there are small >passages in it and I'd rather be sure everything got oil. I've been a mechanic since the sixties, and have rebuilt untold numbers of engines. I've never seen oil passages that can't flow adequate oil of a reasonable viscosity for the temperatures involved. And I know enough about oils to know what is safe. If you know how to read the manuals, most show a range of oil viscosities acceptable for a range of temperatures (or did up until a few years ago). In areas where temperatures do not change much, single weight oils CAN be acceptable and effective under certain conditions. I don't recommend them. But I DO recommend, in many cases, oil a bit heavier than the manufacturer recommends. And I reccomend wider viscosity ranges than some manufacturers recommend. A 10W40 oil is totally acceptable in place of a 10W30 IF IT IS CHANGED OFTEN ENOUGH. The "shear breakdown" boogeyman does not even begin to be a factor at 3000 mile change intervals. Even at 5000 it is negligible. By 8000, all bets are off. And 10W40 has the advantage that it holds viscosity better under high operating temperatures. Although more wear MAY be caused by cold starts, more serious damage is caused faster by lack of lubrication at high temperatures and high speeds and loads. Catastrophic failures seldom accur at startup on a cold engine. That said, you are likely best to follow the manufacturer's specifications TO THE LETTER, as you obviously don't know enough about engines or oils to make any educated descision to do otherwise. > -- Posted via a free Usenet account from http://www.teranews.com
From: SMS on 30 Mar 2007 11:18 clare at snyder.on.ca wrote: > In your world, perhaps. In the real world, the thermostat often opens > all the way, Not just often, virtually always. Have you ever tested a thermostat by submerging it into water then heating the water? It's a very tiny range of temperatures, well below operating temperature, where it's only partially open. It's designed to be open or closed, not anything in-between.
From: Steve Barker on 30 Mar 2007 11:32 There's only one problem with $ynthetic "blends". To be called a blend, the batch only has to contain ONE DROP in thousands of gallons. So, there's a good chance that any 'blend' is not much $ynthetic. -- Steve Barker YOU should be the one controlling YOUR car. Check out: www.lightsout.org "Eeyore" <rabbitsfriendsandrelations(a)hotmail.com> wrote in message news:460CDACB.DFD694F0(a)hotmail.com... > > > clifto wrote: > >> SMS wrote: >> > Remember, even Mobil 1 and Amsoil are only semi-synthetic. They use >> > synthetic base stock but then add petroleum based carrier oil. >> >> Everything I can find at www.mobil1.com suggests that Mobil 1 is fully >> synthetic. > > That's my understanding too. > > Semi-synthetic is considerably less expensive and a good option IMHO. > > Graham >
From: Ulysses on 30 Mar 2007 12:36
"C. E. White" <cewhite3(a)removemindspring.com> wrote in message news:46091844$1(a)kcnews01... > Most major automakers agree: The adage that you should change your > car's oil every 3,000 miles is outdated, and even 5,000 miles may be > too often, The Associated Press reported. > > Ford Motor Co. became the latest manufacturer to extend its oil life > guidelines, making public that it is raising the recommended oil > change interval from 5,000 miles to 7,500 miles on its newly > redesigned 2007 models and all subsequent redesigned or new models, AP > said. > > The company, like many other manufacturers, said last week that higher > oil quality standards and new engine designs were responsible for the > change, which affects vehicles driven under normal conditions. L&MT > > This must be the longest thread in history of this newsgroup. I don't see how anyone can say that a certain interval is correct. If I still had my '93 Escort with the 1.9L engine I'd change the oil every 3,000 miles. In my '91 Explorer with the 4.0 OHV I change it every 20,000 miles (more often if I'm feeling real ambitious). If an engine has worn rings etc the oil is going to get dirty and diluted faster than if the engine is in good shape. The 1.9L and the 4.0L are not the same thing. |