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.

 

[Sgt Slag]

It was the Rotella T6 5W-40 that I had issues with [now available in 15W-40 (JASO MA/MA2), 5W-40 (JASO MA/MA2) and 0W-40 (not JASO rated!), but in the past, T6 was only available in 5W-40]. I now use T6 15W-40, and my issues disappeared. I agree, the cold viscosity difference seems trivial. I just have to go with what I experienced. It was an issue two years, two oil changes, in a row, until I switched to the 15W-40 viscosity. I love the Rotella T6 oil for my motorcycle. I bought Shell transmission oil for my tractor, based on my past experiences; used Shell Rotella in my tranctor's engine, when I changed that after I bought it, as well. Great products, great prices, IMO.

I know that more modern car engines are very intolerant of oils which are outside of their specified viscosity ranges (voids the warranty), so I suspect diesel engines are likely running with similarly tight tolerances, which won't do well with oils outside of the specified viscosity ranges. Just offering free advice, worth every penny paid for it. LOL! Cheers!

 

[Texasmark]

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

Diesel engines ignite by "compression". They require the additives in "C" rated oils, not "S" only which is for "spark" ignited systems. Diesels run higher compressions and have higher wear potentials and need the extra additives. Usually C rated oils are also rated for S service but not vise-versa. So when viewing the starburst look for the C rating.

 

[Texasmark]

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.

Mobil 1 markets 0w-XX synthetic oil. What that means is that it stays fluid at any temp down to some level. The XX is for the high temp operation which is important to the engine design which, depending on things like manufacturing tolerances to use the thinner (more efficient) oils, so today you see a lot of XW-20 oils specified in Honda cars for example... I have one. My Silverado is specked for 5W-30...different design tolerances. Mobil 1 0W-20 or 30 is guaranteed to satisfy the requirement for 5w-XX oils.

 

[Robin Veerman]

Thinner oils have more to do with fuel economy rating’s here in NA. The same vehicle/engine in Saudi Arabia will most likely have a heavier oil recommendation like 10w40 or 15w40…

 

[Texasmark]

Thinner oils have more to do with fuel economy rating’s here in NA. The same vehicle/engine in Saudi Arabia will most likely have a heavier rating like 10w40 or 15w40…

Numerous sources mention that initial startup, oil starvation is the most destructive time of engine operation. Low W ratings are your friend!

I am a holdover heavy oil preferrer guy. Used to be I ran15W-40 in my 5 liter '88 Ford P/U. If the truck sat for awhile, upon start up, I'd hear lifter clatter for a few seconds, same thing when starting after an oil change.

I switched to 10W-30 and never heard it again.......clatter is wear and tear with hydraulic lifters especially and I kept my oil clean....regularly changed and drove 20 miles one way to work.....so it wasn't all sludged up and I bought it new.

 

[ovrszd]

Two very important things are critical to diesel engine life. Clean oil. Clean fuel. A third would be the correct oil.

 

[RalphVa]

Could use it but change at 100 hours instead of 200 because of carbon buildup. Think this is the only difference between gas and diesel engine oil: more/special detergent to keep carbon in solution in diesel oil. Did it once on our 1983 240D Benz.

 

[mo1]

Diesel engines ignite by "compression". They require the additives in "C" rated oils, not "S" only which is for "spark" ignited systems. Diesels run higher compressions and have higher wear potentials and need the extra additives. Usually C rated oils are also rated for S service but not vise-versa. So when viewing the starburst look for the C rating.

The "C" in the API "C" categories is for "commercial," not "compression." The "S" in the API "S" categories is for "service," not "spark." An oil with just an "S" rating will also have the "sunburst" logo containing the words "For Gasoline Engines." Also there are the "fuel economy" API FA-4 diesel engine oils that aren't compatible with the "C" specification oils, and about all needs to be said is to not use them.

The main difference in the "C" and "S" oils is the soot dispersants in oils designed to be used in diesel engines. The emissions systems on new diesels and gasoline engines are also different, and the emissions systems in each can get fouled if the wrong oil is used when the normal small amount of oil is burned through normal operation and the ash ends up going through the emissions system. Most "C" rated oils will also have an "S" rating but there are a lot of "S" rated oils without the "C" rating, as an oil designed to be used in a gasoline engine won't need the dispersants the diesel oil will, and them not being present will have the oil not be able to get a "C" rating. However, a lot of the "C" rated oils that carry an "S" rating as well carry older "S" ratings as some of the components in a typical "C" rated oil are present in quantities that would make an oil fail the newer "S" specifications, so it will instead be rated for an older "S" spec like "SJ" or "SL" instead of a newer one like "SN" or "SP." Zinc concentration in particular is limited in newer "S" specs much more so than in "C" specs.