Why some people use monograde ?

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Originally Posted By: tig1
Not yet, but staright wt. oils are a thing of the wayyy past. No need for those any longer. Old school. I know since I used them.


LOL! My Jeep turns 5 and 10W30 oils to water! SAE30 holds up VERY well. Straight grades still have their place.
 
Originally Posted By: tig1
Water?? Not familure with that term.


Meaning shearing as thin as water.


Originally Posted By: Hoosier_Daddy
i think people see single grade and think 30w-30. not really the case though



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Originally Posted By: Zaedock
Originally Posted By: mechanicx
I think one disadvantage of for instance a monograde 30 weight in hot climates is it can sometimes have a thinner viscosity above 100C oil temps than a 5W/10W30.


What do you think happens to 5/10W30 above 100*C? There's a reason we use straight weights in lawn mowers during the hot summer!




Actually I've used 10W30 in Briggs&Stratton engined lawn mowers without issue. It makes for easy cold starts in summer time
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. Hondas even recommended 10W30. Of course all oils thin at higher temperatures, but because the 30W can have a much lower viscosity index than 5/10W30 you expect it to thin more above 100C.
 
I have seen a 5w or 10 --30 in B&S using oil that you would not think a straight 30 would solve, however when switched over have zero use, and that's with the same brand oil !! B&S says in the owners manual says to use 30 weight oil unless below 40* ( I think I have the correct temp) or consumption of oil, loss of power, and after all of that you choose to still use the 5w-30 then you will need to cut the OCI in half almost. I'm not sure about the new engines, however I have seen that the straight weight oils work much much better in the B&S, and Kohler cast iron series, I think the newer Kohler engines do recommend only a multi-weight oil due to a lifter type change.
 
Another thing you've got to remember is that when the first multi-grade oils came out and were extensively used by the public the Viscosity Index Improvers (VIIs) were not what they are today. Many early adopters of multi-grade oils did get burned by multi-grade oils *quickly* shearing out of grade and mechanics picked up on this and started recommending that their customers stick to single grade oils. While the VIIs have dramatically improved in the interim, the bias against multi-grade oils achieved the status of urban legend and some mechanics or DIYers maintain their original stance even untill this day. I'm sure there are still some old mechanics around telling horror stories about multi-grade oils quickly shearing out of grade - stories that were true at one time but by in large are no longer valid. If it's not old mechanics who remember when the first multi-grades were rolled out it's their children or grandchildren who remember that "old Grandpa Jones said that multi weight oils were pure junk". Old info dies hard sometimes.

That said, for the climate that the original poster described, I don't think using a straight weight oil would be a the end of the world, though I don't think I'd use straight 40 wt in a gasoline engine at those temperatures (in a Diesel engine sure). In a gas engine for the temperatures described I would think that straight 30 wt would work well, but of course I'd check the manufacturers recommendation first.
 
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Originally Posted By: mechanicx
Actually I've used 10W30 in Briggs&Stratton engined lawn mowers without issue. It makes for easy cold starts in summer time
lol.gif
. Hondas even recommended 10W30. Of course all oils thin at higher temperatures, but because the 30W can have a much lower viscosity index than 5/10W30 you expect it to thin more above 100C.


You're right about Honda mowers recommending 10W30. In fact, I'm pretty sure that the manual on the Honda Harmony push mower I bought in 2001 even suggested that using a synthetic was a good thing. Since it's the best mower I've ever owned and I want it to hang around as long as possible I figure that half a quart of full synthetic every year is pretty cheap insurance.
 
Briggs and Stratton recommend 5W30 synthetic as their first choice in their engines, and they recommend it for all temperatures between -20 degrees and +120 degrees.

I have used 5W30 M1 in my Honda engined mower since I purchased it in 2000, and it does a one year or about 60 hour OCI with NO oil consumption. It now has about 525 hours on it. I have an hour meter on it.

Some of you older folks may remember that back in the days of single grade oils, 20W20 was the oil of choice for all but the coldest temperatures in most American cars. We would only use 30W when an engine begin to burn an excessive amount of oil. My Dad gave me a 1954 Ford when I graduated high school in 1954. In 1959, I had 140,000 hard miles on it. (I was 17 to 22 years old). I never had to use 30W in it because it never did use any oil or smoke. Most of the miles were highway miles.

I sometimes wonder if the 0- or 5W20 oils of today are as good as the straight 20 weights of back then.
 
I've been using my Delo SAE30 in my 1986 Kubota mower and it runs great with a 1 pull start (unless I forget to open the fuel valve LOL). I just removed/cleaned the carb last year and it looked pretty good inside.
I change the oil once a season and use Stabil in the gas. I think I changed the plug once over the years.

If I were to buy a new mower, I would probably try synthetic (Q-Torquepower) 10w30. I changed the oil in my snowblower to Havoline 5w30 dino prior to being put away. After stocking up on all the Q and PP, I might try one of those in the 5W30 flavor next time.
 
I wonder about this: a monograde would be thicker at even a not very cold startup.
There will be a big viscosity difference @20 celsius (which is pretty balmy) and at @140. Would this not
lead to increased startup wear compared to multigrade?

Arent's synthetic base stocks inherently of high viscosity index?
Can they even make a monograde out of a pao, ester or gtl base stock?
(IMO the only 3 base stocks in use that are worth bothering with) .
So if I had to give those up to get a monograde, it would be a non-starter for me.
 
For all of those varied questions you would be better off to start a new thread rather than digging up this old one.

But to answer one of your misconceptions, start up wear is a myth. There is sufficient MOFT at startup to prevent wear as long as the oil can be pumped
 
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For all of those varied questions you would be better off to start a new thread rather than digging up this old one.

But to answer one of your misconceptions start up where is a myth. There is sufficient MOFT at startup to prevent wear as long as the oil can be pumped
I don’t understand why people dig up an abandoned thread. Just start a new one
 
Originally Posted By: mechanicx
I think one disadvantage of for instance a monograde 30 weight in hot climates is it can sometimes have a thinner viscosity above 100C oil temps than a 5W/10W30.


What do you think happens to 5/10W30 above 100*C? There's a reason we use straight weights in lawn mowers during the hot summer!


I'm a SAE30 user. I love it! I picked up 36 gallons of Chevron Delo 400 SAE30 (HDEO) during an Auto Zone clearance back in '05 for $.99/gallon!
I use it in my Jeeps, especially my trail rig which sees a mix of frequent start/stops, long idle, and extended rpm use in compound low. I've had great UOA number's with it. It has a nice -24*F pour point and acts more like a 15W30. It's a great three season oil.
Hard to argue with you and your usage. :)

Have to ask though, "you're still drawing down that 36-gal reserve of Delo 400 straight-weight? I assume it's held up well over that period? Shake and pour, eh?"

Thanks.
 
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