Diesel oil or not.

[Rat Rod Mac]

I have a Kubota 900 RTV with the diesel engine in it. It's time to change the oil and it calls for 10w-30. I have a bunch of Pennzoil Platinum High Mileage 5w-30 and was wondering if this could be used. It does not say anywhere on the jug about using it in a diesel engine. Would this oil be ok for this application? Thanks. RRM

 

[Williy]

If you don't like your tractor go ahead and use it.
If the oil can don't say for diesel its for gas engines

willy

 

[MAX-24-Dean]

No, the oil is not good for any diesel engine. Always use oil "labeled" for use in diesel engines.
Diesel engine oils have Lubricity additives, and base detergent additives in oil to aid in keeping acid content down.

 

[hosspuller]

Engine oil is certified by the API. The "Doughnut symbol" tells you what the oil is rated for. Diesel or gasoline... even model year.

See here for full details >> https://www.api.org/-/media/files/certification/engine-oil-diesel/publications/motor oil guide 1020.pdf

If it doesn't have the API Doughnut or Shield ... I would NOT use it in my engines. There's recycled oil sold for engines. Federal gov't uses it, but your tax dollars pay for the repair or replacement...

On a related topic ... Hydraulic oils for tractors are NOT certified industry wide. That's why most advice is to use the manufacturer's oil. Compared to tractor parts and labor, oil is cheap even if the dealer price seems out of sight.

 

[dodge man]

It’s probably API labeled but not for diesels. Probably not the end of the world if you used it in a diesel but there is a difference between diesel and gas engine oils. I wouldn’t do it.

 

[Robin Veerman]

I have a Kubota 900 RTV with the diesel engine in it. It's time to change the oil and it calls for 10w-30. I have a bunch of Pennzoil Platinum High Mileage 5w-30 and was wondering if this could be used. It does not say anywhere on the jug about using it in a diesel engine. Would this oil be ok for this application? Thanks. RRM

Engine oil: API Service CC, CD or CF Below 0 °C (32 °F) : SAE10W, 10W-30 or 10W-40
O to 25 °C (32 to 77 °F): SAE20, 10W-30 or
10W-40
Above 25 °C (77 °F): SAE30, 10W-30 or 10W-40
***
Top line is the specific oil type that you need, but the funny thing is they’re already obsolete. Check that the oil label has CK** specifics and you’ll be using a diesel oil. The “C” stands for compression ignition, which is what a diesel engine is. Diesel specific oil is important due to the diesel contaminants that need to be addressed, which a gas oil doesn’t do.

 

[Williy]

Diesel oil has special additives to take care of the
high volume of soot etc that diesel engines create

willy

 

[Sgt Slag]

The viscosity is incorrect, as well: the manual calls for 10W-30, and the oil proposed for use, is 5W-30. The 10W is thicker, at cold temperatures, compared to 5W. While it sounds like a small difference, I can tell you that I did the same in a motorcycle: I used 5W-40, when the maker specified 10W-40. My clutch started having issues, as well as my transmission having issues shifting (engine oil is shared with the transmission on my motorcycle). I switched back to 10W-40 oil, and my clutch and transmission issues disappeared.

Granted, I am comparing a motorcycle engine/transmission to a diesel tractor engine, but the principle is the same: use the specified viscosity range of oil mandated by the maker -- their engineers specified a particular viscosity range for very good reasons! Modern internal combustion engines have very tight tolerances -- move outside of those tolerances and damage is extremely likely to occur! Cheers!

 

[Robin Veerman]

Probably the above issue was that the oil which caused your clutch/transmission grief wasn’t wet clutch compatible? Should’ve specified JASO-MA. The replacement oil then returned your transmission to normal, which was probably wet clutch compatible. You’re lucky that you didn’t have to replace the clutch. However, your point about meeting the correct requirements for a specific application is spot on, as indicated by your own experience.

 

[Grumpycat]

The viscosity is incorrect, as well: the manual calls for 10W-30, and the oil proposed for use, is 5W-30. The 10W is thicker, at cold temperatures, compared to 5W. While it sounds like a small difference, I can tell you that I did the same in a motorcycle: I used 5W-40, when the maker specified 10W-40. My clutch started having issues, as well as my transmission having issues shifting (engine oil is shared with the transmission on my motorcycle). I switched back to 10W-40 oil, and my clutch and transmission issues disappeared.

Granted, I am comparing a motorcycle engine/transmission to a diesel tractor engine, but the principle is the same: use the specified viscosity range of oil mandated by the maker -- their engineers specified a particular viscosity range for very good reasons! Modern internal combustion engines have very tight tolerances -- move outside of those tolerances and damage is extremely likely to occur! Cheers!

The difference between 5W- and 10W- is trivial on a motorcycle. At 70°F and above they are essentially the same.

If you clutch slipped then it had more to do with the specific oil and nothing to do with 5W. Many automotive oils simply slip in the wet plate clutches of motorcycles. The only independent assurance of good clutch performance is to look for JASO MA or MA2 compliance.

In years past Shell Rotella T6 5W-40 has been a very popular motorcycle oil. Clutch works just fine using this oil in my Yamaha FJR, but the transmission doesn't click between gears as nicely as it does with other oils. Automotive Mobil-1 15W-50 also clutches fine but shifts poorly. And some Castrol motorcycle-specific oils similarly. A discontinued Valvoline synthetic motorcycle oil worked best but am now using the WPS store brand "Firepower" 10W-40. Shifts nice, clutch grabs hard. Hate that brand name but it is apparently a good oil.