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85_Ciera_Rebuild
01-27-2008, 05:43 PM
Being winter time around here, I just changed oil on 161,000 mile 1988-2.8 motor with 5w-20w to see if oil pressure is similar to 5w-30w oil. Only run seven miles, and oil pressure seems similar...but I'll have to do some longer runs to see what happens under different loads and temperature.

I will most likely upgrade back to 5w-30w, or 10w-30w in summertime, but after reading these two articles,

Motor Oils - Fuel Economy vs. Wear (http://www.machinerylubrication.com/article_detail.asp?articleid=518&relatedbookgroup=Maintenance)


A Tight Squeeze (http://www.machinerylubrication.com/article_detail.asp?articleid=365&relatedbookgroup=Lubrication)

it seems that no harm will come when using 5w-20w if extra stress (heat..heavy throttle load) does not exist.

Walmart's SuperTech label suggests it can handle gas Turbo engines...but I would only use this lighter weight under light load conditions. The oil's temperature in oil-pan is what affects actual viscosity, and in colder environments, the outside air is cooling the oil...so cooler oil gives a higher viscosity.

Those two articles give a full overview...but what I gleamed from them was that under light conditions it should not make a difference...except for a pinch more fuel economy...as measured in tenths of a gallon...not much.

turbokinetic
01-27-2008, 10:24 PM
Shell Rotella all the way!! :rock:

Any engine I own will see no other oil!

Mom's 89 LeSabre with lightly ported and 9.5:1 compression 3800 V6 gets 35 MPG with Rotella 15W40. Lasted 370,000 miles before first rebuild. Before mods it got 30 mpg.

My t-type with turbo V6 has withstood 100,000 miles of HellBoost with Rotella and no coking in turbocharger or bottom of pistons

There are other oils similar, but this brand works so well, why change?

Good articles; reinforced what I already beleived and have learned at engine school at work.

Thanks,

David

ochy38
01-27-2008, 10:40 PM
I almost paid the $2 less for the supertech oil change @ walmart. The guy talked me out of it because.. its recycled motor oil. Maybe not a bad thing.. but not goin in my car.. sorry just a random comment

85_Ciera_Rebuild
01-28-2008, 12:37 AM
...its recycled motor oil. Maybe not a bad thing..

Its got the official ratings on it....and no doubt Walmart contracts out...so it could be brand A, B, C...etc....but in theory, those ratings are suppose to mean something.


My other purpose of using 5w-20w is to give the engine one last flushing...vehicle was driven in small rural town, it had sludge in oil pan, and I'm trying to cleanse passageways...etc.

I drove vehicle again today, and except for idle, oil pressure is doing about the same or better, which is weird...but outside temperature and engine load will affect oil pressure.

Maybe a quirk, but engine temperature dropped down one bar...and oil pressure went up one bar...temperature was about 45.9 °F / 7.7 °C...and I was doing light footed driving below 45 mph...never seen that happen before, but 5w-20w has less friction...maybe just a quirk. But, as one article noted, "If we could eliminate the need for the oil by eliminating the friction between the engine component surfaces, then we could eliminate a large portion of the horsepower losses in the modern combustion engine." I have no idea what effect this oil has on engine temperature, but I do know from another engine when it was several quarts low, the engine temperature did rise...for some reason:jawdrop:

I'll know more later this week...but at "hot idle," it was down to about 10 p.s.i., but as soon as throttle was depressed, oil pressure was normal, or better.

I'll be putting in 5w-30w next oil change, or 10w-30w, if it is warmer then. Fuel mileage wise, I don't think it amounts to a hill of beans...I was looking for 0w-30w oil, but none was around...only found Mobil One, which had 0w-40w, but too high price.

85_Ciera_Rebuild
01-28-2008, 12:42 AM
Shell Rotella...15W40

Where you live, it may work fine...but 15W40 oil will exercise the starter in cold environments...better have a good battery up here during cold weather with 15W40.

Normal morning temperature around here is about 17 °F / -8 °C...and it does dip lower.

I've used 15W40 in summer on V8 motors...and I think Rotella has a formula for gas engines...I think...years ago, I don't think they did.

85_Ciera_Rebuild
01-28-2008, 01:01 AM
Here's an guide describing those labels (http://www.burkeoil.com/pdf/oilguide.pdf).

turbokinetic
01-28-2008, 01:18 AM
...found Mobil One, which had 0w-40w...

AgChem Equipment Co. used to send me to Jackson, MN in February for training. I have driven my 86 Century and 72 Nova. The year I drove the Nova, I put Mobil1 0W40 oil in it. The wether got down to -12°F. The small-block V8 turned over at -12°F just as it does on a 40°F morning here in AL. That oil works exactly as designed.

With engine at 190°F the oil pressure was no lower than it is with the normal 15W40 I use.

I put a quart of it in the freezer quick-freeze compartment and let it get to -30°F overnight. Next day I poured it. It poured freely into a funnel and into another bottle. The oil flowed fine but it was so cold that FROST formed on the surface of the flowing oil! Wild to look at indeed.

I forgot to change out the oil on my Century one year and left the 15W40 in it. It got to -16°F that year. The engine turned over slowly but it started more easily than I expected! I left it running for about an hour before driving off. The exhaust FROZE and fell to the ground in a PILE behind the car, as shown below.

http://68.209.87.173/Temp/FrozenExhaust.jpg
http://68.209.87.173/Temp/FrozenExhaust2.jpg


That was COLD. I had a bottle of Vaseline hand lotion (oil based) and that froze solid. Had to "barge" the motel door open with my side to break the ice seal and get the door open that morning. Nasty.

Some of y'all from up North have seen this plenty, I but most southerners I talk to don't beleive it can happen until shown this picture!

85_Ciera_Rebuild
01-28-2008, 05:48 PM
I almost paid the $2 less for the supertech oil change @ walmart.


Price and API ratings should always be considered...for gasoline vehicles at Walmart:

Rotella 15W40....................$2.40/quart on gallon jug

Mobil-Clean-5000-5w-30..................$2.22/quart

Phillips-5w-30-synthetic-blend.............$1.70 (or so)

All three will work in gasoline engines, but top two have CF ratings, but Rotella has other diesel ratings. I would have to fetch Walmart's SuperTech oil's rating, but it too has good ratings on it.

What I do notice is that some oils are consumed quicker than others in older motors...but normally, as you increase the viscosity rating, oil consumption decreases a pinch in older vehicles.

I have been using Phillips 5w-30 this winter...but it appears when using SuperTech when driving at a steady rate like 50 mph on similar temperature days, the 5w-20 SuperTech appears to have a pinch more oil pressure than Phillips.....oil pressure is related to viscosity, which in turn is related to engine's oil temperature.

In theory, 5w-30 should have higher oil pressure at same operating temperature than 5w-20 has...I'll need to do some more driving to confirm this...but if true, then it suggests less friction inside engine, which means oil temperature is lower, or it means 5w-20 and 5w-30 viscosities are not "true."

When I saw oil pressure at around 10 psi...hot...the engine was "hunting" for idle RPM...so idle rpm was dipping below computer set point...something I have to fix....but, when idle rpm is constant, the hot oil pressure appears to be the same for these different oils.

Next oil change, I think I will use Mobil-Clean-5000 in either 5w-30 or 10w-30...its got some good API ratings, for the price. Needless to say, if you were going to do some serious highway driving in SumerTime (higher air temperatures), 15w-40 or straight 30w or 40w would be the better oil to use...but overall, for most people's needs, 10w-30 works fine.

turbokinetic
01-28-2008, 09:05 PM
When I saw oil pressure at around 10 psi...hot...the engine was "hunting" for idle RPM...so idle rpm was dipping below computer set point...something I have to fix....

Something to think about, I've seen calibrations that needed a certain amount of load on the engine to idle stable. With an abnormally light load, the idle RPM will oscillate as you describe.

I've seen this on big diesels (9 liter) designed to turn a set of hydraulic pumps that have a parasitic load even in "neutral." The gearbox failed between the engine and pumps and the engine would idle up/down/up/down/up/down with no load.

The thinner oil with less oil pressure requires less torque to drive the oilpump, and less drag from oil shear in the bearings, so the engine turned freer at idle speed. I wonder if the system was so close to an oscillatory idle (in need of tune up/ vacuum leak etc.) that this small load reduction was enough to make it act up?

Just surmising!:)

Later,
David

85_Ciera_Rebuild
01-29-2008, 07:19 PM
Shell Rotella all the way!! :rock:... Rotella 15W40.


Found this tidbit interesting:

Using Diesel oil for flushing (http://www.carbibles.com/engineoil_bible.html#flushing)

A question came up some time ago about using diesel-rated oils to flush out petrol engines. The idea was that because of the higher detergent levels in diesel engine oil, it might be a good cleaner / flusher for a non-diesel engine. Well most of the diesel oil specification oils can be used in old petrol engines for cleaning, but you want to use a low specification oil to ensure that you do not over clean your engine and lose compression for example. Generally speaking, an SAE 15W/40 diesel engine oil for about 500 miles might do the trick.

Not sure how one would "loose compression?" A lot of horse feathers out there on this topic.

Zaloryan
01-31-2008, 09:05 PM
I use Castrol. What's everyone's opinion on Castrol vs. their preferred brand? :huh:

85_Ciera_Rebuild
02-01-2008, 12:38 AM
Something to think about, I've seen calibrations that needed a certain amount of load on the engine to idle stable. With an abnormally light load, the idle RPM will oscillate as you describe.


This hunting happened when oil temperature was at or near normal temperature with 5w-20 oil...which it suggests this lighter oil may have played a role.

1988 2.8 motor was setup to use SF/CC, and when SF oil is researched, it was a much "tougher" oil:

SH oil came after SF, and SH accomplished the following:

When compared to SG motor oil, (http://www.burkeoil.com/pdf/oilguide.pdf) this oil produces 19% less engine sludge, 20% less cam wear, 5% less engine varnish, 21% improved oxidation, 7% less piston varnish, 3% less engine rust, and 13% less bearing wear.

Consequently, since 1988, there has been 5 improved classes of oils (SF to SM), which are slicker in effect, and I was using 5w-20 instead of 5w-30...which all this means it took less horsepower to run the engine at temperature, and a pinch less horsepower to run the oil pump at operating temperature. Thus, this could have effected the default computer program and assisted in causing the engine r.p.m. to go hunting up/down at idle when at operating temperature.

After looking at specifications on Mobil-Clean-5000 for 5w-30, since it has the gas SM and diesel CF ratings, I'm going to use it next, and see what happens. If hunting still happens, I'll try Mobil's 10w-30 in warmer weather.

85_Ciera_Rebuild
02-01-2008, 12:50 AM
I use Castrol. What's everyone's opinion on Castrol vs. their preferred brand?

Imho, see what vehicle's engine was suppose to use for API Classification (here's complete listing of them (http://www.burkeoil.com/pdf/oilguide.pdf))....and look at newer oils, which exceed the original OEM specs.

In my case, OEM spec was for SF/CC, but I will be using next oil change, SM/CF.

Castrol works...I'm a penny pincher, and look for lowest cost with right API specs.

85_Ciera_Rebuild
02-07-2008, 03:00 AM
I wonder if the system was so close to an oscillatory idle (in need of tune up/ vacuum leak etc.) that this small load reduction was enough to make it act up?

I think now the engine "hunting" was due to lighter weight oil ( 5w-20 ); but yes, there are two small vacuum leaks that may also be related.

I'm using 5w-30, and when engine oil is up to temperature, at an idle, it will oscillate a small pinch, then smooth out.

I suspect if higher weight oil was used, like 10w-40, hunting would not exist.

Later this year, I may pull intake manifold off, install valve seals/etc., and then examine it.

Buick_powa
02-22-2008, 10:42 PM
I use castrol Syntech 5W30 on an 213XXX km engine! does not take a pinch of it in 10000 km (yeah skipped an oil change :s

85_Ciera_Rebuild
07-14-2008, 03:33 AM
Shell Rotella all the way!! :rock:



Motorcycle usage (http://en.wikipedia.org/wiki/Shell_Rotella_T)

Though marketed as an engine oil for diesel trucks, Rotella oil has found popularity with motorcyclists as well. The properties of heavy duty engine oils tend to map to the same requirements of motorcycle oils, particularly those whose engine and transmission share the same oil. (This is called a "shared sump" design, which is unlike automobiles which maintain separate oil reservoirs - one for the engine and one for the transmission). The chemical additives found in heavy duty engine oils work well with motorcycles. In addition, the lack of "friction modifiers" in truck oils such as Rotella means they do not interfere with proper wet clutch operations.

Though not yet officially announced by Shell, posts in various motorcycle-related forums cite e-mail confirmation from Shell that Rotella 15W-40 CJ-4 has been tested and shown to meet the JASO-MA friction test. This particular certification is important for motorcycles because of the clutch design which is bathed in the engine oil. This is known as a "wet clutch." Oils that have excessive "friction modifiers" tend to make wet clutches slip. Indication that Rotella T Triple Protection passes the JASO-MA friction test offers one more reason to seriously consider Rotella T for motorcycle use.

85_Ciera_Rebuild
07-14-2008, 03:40 AM
Shell Rotella all the way!! :rock:



I tried 15W-40 viscosity today....and compared to Mobil 10w-30....upto 5 psi higher idle pressure (depending upon engine temperature when "hot"), and oil pump's bypass kicks in around 1800 RPM (+/- 200 RPM), which is around 60 psi.

Hence, overall higher pressures when engine is up to temperature....and for cold starts in warm weather, pressure is quite high, like in winter weather for 5w-30.

85 Holiday
07-14-2008, 04:03 AM
Truck gets Shell Rotella 15w-40 summer 5w-40 synthetic winter
Grand Prix gets Mobil 1 synthetic 5w-30
The other cars get 5w or 10w-30, doesn't matter who the maker is. I get a few jugs when it goes on sale (generally castrol or valvoline) All get Acdelco filters

85_Ciera_Rebuild
07-14-2008, 04:15 PM
Truck gets Shell Rotella 15w-40 summer 5w-40 synthetic winter


I don't know if its the Shell Rotella or the 15w-40 that makes the difference....since the end effect causes higher overall oil pressure, which "floats" bearings more so.

My opinion is that all engines being "equal," and with similar oil change intervals, what determines engine life then is how much horsepower per cylinder is acting upon each piston (of similar size).


Even in big truck motors, more horsepower used, the shorter the life; Combines, for instance, are evaluated by separator time, which represents when combine is threshing the crop...full engine load generally.


I have a 267 GM V8 with 200,000 miles on it....and I'd say its got a good 50,000 miles left....reason why, it is a low horsepower V8...something like 120 HP new.


Hence, changing the oil, regularly, is important, but if motor is always being loaded, it too will have a short lifespan.

Rotella 15w-40 may be a better oil for longer oil intervals, but I suspect any oil of similar viscosity will work, if oil is change frequently. 15w-40 would be better with higher load conditions, but for around your local area with light chores, its not needed, imho.

dagr8tim
07-14-2008, 07:56 PM
Being as this thread is alive again. Has anyone checked out www.bobistheoilguy.com?

There are some really intelligent people over there. I've read a bit and started to look at auto lubrication in a slightly different manner.

85 Holiday
07-14-2008, 08:44 PM
I don't know if its the Shell Rotella or the 15w-40 that makes the difference....since the end effect causes higher overall oil pressure, which "floats" bearings more so.

My opinion is that all engines being "equal," and with similar oil change intervals, what determines engine life then is how much horsepower per cylinder is acting upon each piston (of similar size).


Even in big truck motors, more horsepower used, the shorter the life; Combines, for instance, are evaluated by separator time, which represents when combine is threshing the crop...full engine load generally.


I have a 267 GM V8 with 200,000 miles on it....and I'd say its got a good 50,000 miles left....reason why, it is a low horsepower V8...something like 120 HP new.


What about taxi companies?? They have cars that have more than 120hp stock and they easily put that much mileage on the motor. Maintain said product and it'll last a long time, if you don't then of course it won't last.

I did not treat my 85 Holiday very well, but I did keep up on engine maintenance. The motor had well over 200,000 miles on it and was a very reliable car. If I would have looked after the body ie: undercoating. I would still be driving the car today.





Hence, changing the oil, regularly, is important, but if motor is always being loaded, it too will have a short lifespan.

You're basically stating the obvious which can be applied to anything... Want a short battery span in your remote control? Keep on pressing the buttons. Want it to last? Get up and hit the buttons on the TV instead.



Rotella 15w-40 may be a better oil for longer oil intervals, but I suspect any oil of similar viscosity will work, if oil is change frequently. 15w-40 would be better with higher load conditions, but for around your local area with light chores, its not needed, imho.

Are you telling me not to put 15w-40 in my diesel??? what!?!

85_Ciera_Rebuild
07-15-2008, 02:53 AM
Are you telling me not to put 15w-40 in my diesel?

Amsoil, and I would agree:kekeke:

AMSOIL Synthetic 5W-30 Heavy Duty Diesel Oil (http://www.amsoil.com/storefront/hdd.aspx) is recommended for diesel engines and other applications requiring any of the listed worldwide specifications and gasoline engines requiring API SL, SJ, SH . . . or ACEA A3.

• API CI-4+, CF, CF-2, SL • ACEA A3/B3, E2, E3, E5 • Global DHD-1 • JASO DH-1 • Mack EO-M+, EO-N Premium Plus ’03 • DDC Power Guard 93K214 • Caterpillar ECF-1-a, ECF-2 • Cummins CES 20071, 20072, 20076, 20077, 20078 • Volvo VDS-2, VDS-3 • MB 228.1, 228.3, 229.1 • MAN 271/3275 • MTU Type 2


But, to save some bucks, buy Rotella 15w-40.....

85_Ciera_Rebuild
07-15-2008, 03:01 AM
Being as this thread is alive again. Has anyone checked out www.bobistheoilguy.com?


I've come across that site before...and glanced at it....as he says:

"This is why it is important not to play home chemist and blend in aftermarket additives that are not designed to be in the oil to start with (http://www.bobistheoilguy.com/states%20of%20lubrication.html)."

Imho, change your oil before they say to change it, and buy a known brand with specs for your vehicle. I'm going back to 10w-30 next oil change, since 15w-40 tends to kick-in oil bypass circuit for my motor....I don't think I need that much pressure.

85 Holiday
07-15-2008, 03:25 AM
Amsoil, and I would agree:kekeke:

AMSOIL Synthetic 5W-30 Heavy Duty Diesel Oil (http://www.amsoil.com/storefront/hdd.aspx) is recommended for diesel engines and other applications requiring any of the listed worldwide specifications and gasoline engines requiring API SL, SJ, SH . . . or ACEA A3.

• API CI-4+, CF, CF-2, SL • ACEA A3/B3, E2, E3, E5 • Global DHD-1 • JASO DH-1 • Mack EO-M+, EO-N Premium Plus ’03 • DDC Power Guard 93K214 • Caterpillar ECF-1-a, ECF-2 • Cummins CES 20071, 20072, 20076, 20077, 20078 • Volvo VDS-2, VDS-3 • MB 228.1, 228.3, 229.1 • MAN 271/3275 • MTU Type 2


But, to save some bucks, buy Rotella 15w-40.....

Just checked out the site and a price, approx $30 for a gallon and I need 2.. Thats a NO!
It would cost more if a dealer had it around here. I don't care what kind of interval it goes. I'd rather put that money in an FS2500 thanks. I'll be very happy continuing to use shell and work my truck haulin horses and plowing snow.

CieraSL92
07-15-2008, 01:36 PM
I have a 267 GM V8 with 200,000 miles on it....and I'd say its got a good 50,000 miles left....reason why, it is a low horsepower V8...something like 120 HP new.


Lower horsepower would tend to make me think said person would be into the pedal more, as in more horsepower required per cylinder.

John B.
08-12-2008, 01:11 PM
My '90 Celeb with a 3.1 had over 240,000 miles on it when I got rid of it. I used whatever oil I had handy with no regard to brand, ratings, weight, etc. The engine never required additional oil even though I sometimes went over 5000 miles between changes. It didn't knock, rattle, or smoke. So my opinion of oil is as long as it's actual engine oil with at least the minimum requirements for your engine, it's fine. Unless you have some kind of high performance engine or use it for trailer towing or racing, I think paying for premium oils is a waste of money.

85_Ciera_Rebuild
08-12-2008, 06:35 PM
Lower horsepower would tend to make me think said person would be into the pedal more, as in more horsepower required per cylinder.

Actually.....owned via farmer.....then someone living in country side who used it as daily driver....then another older person....then me.

It's rather doubtful these others were pedal massagers....it has alot of country miles on it....and the oil was changed religiously.

But, since it could not produce as much horsepower, less "damage" to cylinders/rings/etc could happen...

85_Ciera_Rebuild
08-12-2008, 06:46 PM
My '90 Celeb with a 3.1 had over 240,000 miles on it


Tougher emission laws....better engines....also, not much "work" (horsepower requirements).

Put a trailer hitch on a pickup....and start pulling its full weight rating up/down the mountains....you can kiss that motor good-bye before 100,000 miles.

jeffreyclay
08-15-2008, 10:46 PM
I had a research paper from Valvoline that explained a lot about oils and the specifications.
In a 5W-20 or 5W-30, you have a 5 weight oil in both blends that have viscosity modifiers to provide performance advantages of either a 20 or 30 weight oil, but you are running 5 weight oil. The broader the spread in the weights indicate that the balance in base oil and additives are shifted to the additives and can be a bad thing in some cases. You don't want it to be too extreme. From this I'd prefer a 10W-30 over a 10W-40.
There is an old myth that a 10W-30 is a 10 weight when cold and a 30 weight when hot but when was the last time you saw your oil thicken after it came from a hot engine?
Best thing you could do in my opinion would be to run 100% Synthetic, the wear stops and the protection is better than any crude based oil. Run Amzoil and change it once a year.

85_Ciera_Rebuild
08-16-2008, 12:41 AM
...in my opinion...run 100% Synthetic, the wear stops and the protection is better than any crude based oil.

I think one will find that synthetics can be made via different processes (http://en.wikipedia.org/wiki/Synthetic_oil)...including usage of crude based oil, which is transformed into what is called synthetic.

What is not mentioned, for extended usage interval, is a good filter is required.

Further, if you have an oil burner, one is wasting their money....hence, your engine should be fit to start with, or blow-by gases will be "soaked up" via Crude or Synthetic Oils.


Run Amzoil and change it once a year.

Seems to be an Amzoil echo around here....if a person is only driving say one mile to work, in the humid South....I would question that opinion since engine heat is required to evaporate moisture condensation.

Hence, your mileage may vary...depending upon your location, location, location, and driving habits.

In any event, if you are running extended oil-drain intervals, you should be having your oil analyzed, like at BlackStone (http://www.blackstone-labs.com/faq_gas.html)

85_Ciera_Rebuild
08-17-2008, 03:36 AM
Run Amzoil and change it once a year.

On farm, all diesel engine tractors/etc get an oil sample done with each oil change.

I let one smaller utility tractor slip a year, and then changed oil...so two years went by.

Using decent grade diesel oil, and with about 100 hours on motor, the test sample was OK, according to the lab. I also let the transmission oil slip for several years, and it came back OK.

This tractor, when used, runs so it is up to temperature most all of the time...out here, it is drier (less humidity/rain), than back east.

Without running oil test samples, you are clueless....they run about $15.00 or so...but this is contracted out with a lab for a large group of farmers. Private Sector charges around $20.00 and up.

85_Ciera_Rebuild
09-07-2008, 03:55 AM
There is an old myth that a 10W-30 is a 10 weight when cold and a 30 weight when hot but when was the last time you saw your oil thicken after it came from a hot engine?


I think "betterthanyou (http://60degreev6.com/forum/showpost.php?p=339936&postcount=14)" at 60DegreeV6.com would disagree with your understanding currently:




Also 5W30 and 10W30 are the exact same Viscosity at 200*F. You will only notice a pressure difference when cold. If you want you could run 0W30. Most cars these days are running 0W now in order to reduce cold operating fuel consumption because it is thinner when cold which robs less power.

His point is that if you examine the Viscosity specs at 200*F, you will find them similar for a given higher end weight.

Zaloryan
09-07-2008, 03:35 PM
If the first number on an oil viscosity determines temperature coverage, (i.e. 0-30 all temperatures, 5-30 to zero degrees, and 10-30 to freezing) what benefits come from running a 10-30 in warm weather versus a 0-30 in the same location?

85_Ciera_Rebuild
09-07-2008, 06:12 PM
what benefits come from running a 10-30 in warm weather versus a 0-30 in the same location?

Is there a disadvantage to using an oil that flows better when cold, i.e. 5W30 versus 10W30? (http://www.nordicgroup.us/oil.htm)


Sometimes, but usually not. The crux of the issue is this: the bigger the difference between the cold oil viscosity and the hot oil viscosity, the more the volume of viscosity modifiers and the less the volume of base stock. If you are good about following the manufacturer's recommended oil change interval then stick with the 5W30 if that is the preferred oil for your vehicle, even if 10W30 is acceptable in warmer climates. Older cars may specify 10W30 only. This is because they need a little more viscosity when cold to keep a protective film on the cylinder walls. There have been instances where the larger amount of viscosity modifiers that are present in 5W30 have broken down due to excessive heat and have left carbon deposits on the valves, but this is extremely rare. The proper fix would be to reduce the excessive heat, but the workaround was to use an oil with less viscosity modifiers.



The person who made the 0W30 comment is from Canada....which up there, it is much cooler than down here, overall.

If I had a new engine, or one with lower miles...in Winter Time, I would run 0W30...then change to 10W30 there after in warmer weather.

If I lived down South, I might run straight weight 30w year round...or 15w40 oil

Zaloryan
09-08-2008, 02:05 AM
Thanks, great link and good info. I'm a pretty firm believer in sticking to the specified oil for my motor. I agree that you can get some benefits from running a different viscosity depending on location, however, my motor has so much mileage I shouldn't run anything except the recommended viscosity.

85_Ciera_Rebuild
09-08-2008, 04:34 AM
I shouldn't run anything except the recommended viscosity.

I look at oil pressure....and make a judgment call.

88 Beretta with 2.8...5w30 will work in Winter Time...but with 180,000 miles, I will try 5w30 during coldest part of Winter, but if "hunting" happens again, I will switch to 10w30 this winter.

Local GM dealership has been suggesting on V8s (SUVs) to use 10w30, instead of suggested 5w30.