Why some people use monograde ?

[seremban]

I notice that some ppl in BITOG forum use monograde oil ? Why is that ? Is it because monograde is cheaper than multigrade OR maybe monograde is better than multigrade ?

The normal temperature in my country is 75 - 95 F all year round. I also notice that a huge percentage of commercial vehicles in my country like trucks, buses, fleets etc also use monograde SAE-40 oil. I really don't know why they do this...could it be because monograde is cheaper and they want to cut cost ?

Also synthetics oil manufacturers like Redline, Amsoil and Royal Purple produce and sell synthetic monograde oils. What kind of vehicles use synthetic monograde oils ?

Thank You.


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[addyguy]

Some folks like their oil to have absolutley no Viscosity Index Improvers (VII's) in them.

Above 35-40F, I don't think it makes much difference. Only becomes an issue in cold temps.

 

[02zx9r]

From my understanding, mono-grade oils are more resistant to shearing among other things.

There are people on here that have run straight weight oils in their vehicles and have no issues. I believe GMAN is one that does or did do it.

Heck when I was living in Louisiana growing up and my dad showed me how to change oil he used Castrol SAE 30 weight and that is what I did for several years and did not ever have any issues.

 

[montero1]

The same reason some people still have rotary phones or dial-up internet.

 

[tig1]

300 hundred years ago I used 20wt. Valv in the winter and 30wt. in the summer. Found out about 10-30 and never looked back.

 

[cchase]

My boat uses 30wt. Specifically says not to use multi-grade oils. Don't know why, but it is sure a pain to find 30w synthetics.

 

[saberz]

Originally Posted By: tig1
300 hundred years ago I used 20wt. Valv in the winter and 30wt. in the summer. Found out about 10-30 and never looked back.


Careful we have an immortal in the house.

 

[seremban]

Originally Posted By: addyguy
Some folks like their oil to have absolutley no Viscosity Index Improvers (VII's) in them.



Yes...I know that VII in mineral multigrade oil may cause shearing...but most car manufacturers recommend multigrade oils so I'm sure those car manufacturers know what they are doing ?

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[Steve S]

Originally Posted By: cchase
My boat uses 30wt. Specifically says not to use multi-grade oils. Don't know why, but it is sure a pain to find 30w synthetics.
Amsoil makes a real nice 30wt syn and it is a phone call away and by magic arrives at your front door!!!

 

[ARCOgraphite]

Purportedly, there is no need for multigrade in hot climes. The oil pumps and flows just fine without the need to add nasty polymer stuff to a light 7W baseoil to make it perform like a 30wt. It is speculated that these Vii cause a lot of gum and varnish. Vii are not lubricants. (Just like your sister that added too much flour and cornstarch to the turkey drippings and turned a nice au jus into sludge). That said, other than HDEO, many monogrades are near 10w30 with the newer dewaxed basestcock required for GF4, just the PPD are removed. Going the monograde, non-GF4 route can open you to options for stronger EP additisation in fleet formulas.
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simplistic: The W in the multigrade stands for winter, if you dont have a winter season then ...?
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Me the closest I'll go to a monograde is a 10w30, the Rotella-T CJ4 has all that is needed to protect most any performance passenger car that is not tracked/raced hard to extreme oil temps, though you may give up some % of upper range torque due to the mid/high HTHS.

 

[mechtech2]

seremban - Even if you don't get down to very cold temperatures [like freezing], a multigrade is going to be a benefit.
Why? Because in intermediate engine temperatures up to operating temperature, the multigrade will be somewhat thinner.
This will give you better power and fuel mileage. Not a lot, but in the right direction. Multigrade oils are very good nowadays.

One more thing.. If a vehicle is always running, like some cabs or maybe a bus, the straight weight in a hot climate could be best.

 

[HTSS_TR]

For you hot climate all year, you may be able to use mono-grade 30wt or even 40wt, specially if you can buy it for less than multi-grade oil.

Most oils sold in USA are multi-grade oils, because we have cold temperature in winter in most states. Even in California or Florida where the winter temperatures are rarely below 40F, mono-grade oils are hard to find.

 

[demarpaint]

In the OP's temp range 75*F-90*F a mono grade oil will probably work, well. I never gave it much thought because where I live a multi-grade oil is better for me.

 

[Rand]

above 50F a monograde isnt bad..

and many 30weight monogrades are now similar to a 10w30 with modern refining processes.

the reason there isnt too many monoweight syn oils is that they dont have (or very few) VII's added

 

[cchase]

Originally Posted By: Steve S
Amsoil makes a real nice 30wt syn and it is a phone call away and by magic arrives at your front door!!!


Good to know, I was mail ordering RP 30wt last year and this year ran out of time and picked up some Volvo Synthetic 30wt for it (probably a blend?)

 

[ottotheclown]

Is it just me but doesnt the question sound like the beginning of a joke??

 

[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.

 

[paulo57509]

Originally Posted By: montero1
The same reason some people still have rotary phones or dial-up internet.

That would be my Mom.

 

[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!


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.

 

[tig1]

Originally Posted By: Anies
Originally Posted By: tig1
300 hundred years ago I used 20wt. Valv in the winter and 30wt. in the summer. Found out about 10-30 and never looked back.


Careful we have an immortal in the house.

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.