oil weight change

[Sully2]

You're right it was 5w40 sorry.

If your running the Rotellla SYN 5W-40 as I am...change it on a regular basis with the filter and forget it! I know guys that are runing that stuff in BIG diesels and working them harder than any AG tractor Ive ever seen run in southern Ohio. 500 plus HP Cummins pulling over 40K pounds at 70 plus MPH across NM and west TX and AZ when the temps go over 100 degrees.

My tractor especially will never see that sort of "workout".

 

[coffeeman]

That is getting a little thick, where are you located and what are your max outdoor temps like? Oil that is to thick can hold air bubbles (foam) easier than a thinner viscosity. The air is not released as quickly as it would be in a lighter weight oil. It will also increase the fuel consumption a little. The thicker the oil the more drag it induces which takes away a little HP.

I don't know much about this oil thing. I just use what they say to use and don't really care to figure out why. It's like popcorn; I eat the popcorn and I don't need to know why it pops.

However, I always thought the oil is smart enough to know how thick it has to be. If it's 5-40 the oil will be 5 when it's cold and it will be 40 when needed. If you have 5-50 it doesn't get to the 50 point till it's needed. Of course 15-30 will will only go to 15 on that cold day and only get as thick as 30 at high temps.

With the above thought in mind I thought different weight oil at 100 degree temp will be the same thickness and oil at 200 will be same thickness. Only when needed will the extra thickness kick in. As a result I never worry too much if I have to use something a little different. I don't know why I think this of even if I read it anywhere. Sometime I get things wrong.

Cheers Coffeeman

 

[DieselPower]

Oil does not really "thicken" when it get's hot, the second number of a multiviscosity's oil rating is how it "acts" when at 210 deg F/100 deg C. In multiviscosity oils the first number is what the oil "acts" like at 100 deg F./40 deg C. So a 5W/30 acts like a straight 5 weight oil would at 100 deg F. and would act like a straight 30 weight oil at 210 deg F. The higher the second number the more resistant it is to thinning out at operating temp. You can get to thick though. Engines or anything else for that matter operate at peak efficiency at a certain viscosity. Most diesel engines operate at peak efficiency at operating temp with either 30 or 40 weight. That's why the majority of diesel engine oil is either 10W/30 or 15W/40

 

[coffeeman]

Oil does not really "thicken" when it get's hot, the second number of a multiviscosity's oil rating is how it "acts" when at 210 deg F/100 deg C. In multiviscosity oils the first number is what the oil "acts" like at 100 deg F./40 deg C. So a 5W/30 acts like a straight 5 weight oil would at 100 deg F. and would act like a straight 30 weight oil at 210 deg F. The higher the second number the more resistant it is to thinning out at operating temp. You can get to thick though. Engines or anything else for that matter operate at peak efficiency at a certain viscosity. Most diesel engines operate at peak efficiency at operating temp with either 30 or 40 weight. That's why the majority of diesel engine oil is either 10W/30 or 15W/40

I never knew how that worked. I think back to the days when I had an oil burner. I had a place that would save used oil for me and when I had to use new oil I would get 40 or thicker if I could find it. That slowed the oil burning. Gee, things run so much better today. I can't remember a vehicle using a lot of oil for years now.

Thanks for the answer....Coffeeman

 

[Flywheel]

15/50 is too thick - do as suggested in your operators manual.

I would change it out with the proper oil. I've never even seen 15/50 here in Texas, but traditionally, thicker oils are used on worn engines to provide a little more buffer in areas were tolerances have widened...I shred on 100+ days when I can't even stand it and rely in 15/40

 

[deereman64]

I was going to change to 15w 40 but I still cant find it in synthetic.The shelves are bursting with dino 15w 40. Amazing Huh!!!!

 

[gf5205]

Your John Deere dealer has 0w-40 which is synthetic. Run it year round.

 

[RalphVa]

I use 5w-30 Mobil 1 in my 4010 and change it about once/year (usually about 100 hours). This is the range specified by JD.

I'd only use 15w-50 Mobil 1 if the engine uses oil. Did in my old Gravely. It actually quit using oil the second change on Mobil 1.

I use 5w-40 in my 1983 Benz diesel, if I can get it (they call for 10w-40). Used 5w-40 Shell last time but have found out that it's not a PAO like Mobil 1 (Shell stuff is hydrotreated). Will change back to Mobil 1 next time. Usually use 0w-40 or 5w-40 Mobil 1 for add oil to it cuz I can get these in quarts.

Don't worry about going lighter on the first vis number. Even 0w is heavier at start up than 30w or 40w are at operating temperature, probably even heavier than 50w. Main reason people shyed away from using very high vis ratios in dino oils was because they needed even more additive to get this, and additives often broke down in use. However, Mobil 1 doesn't. They just change the PAO reaction conditions.

Ralph