Which oil 10w-30 or 15w-40?

MrDave03

New member

Equipment
Kubota BX23s
Oct 13, 2021
2
0
1
07840
Hi All, I tried searching and couldn't find anything on the forum. I'm curious.. living on the east coast mid Atlantic. I'll be using my BX23S for some snow removal in temps below 32 deg F. Most of my use would be spring through fall. Has anyone had any issues running 15W-40 below 32 deg? I know Kubota says 10w-30 below 32...or am I fine running 15W-40 all year round?
 

Fordtech86

Well-known member
Lifetime Member

Equipment
L3200
Aug 7, 2018
4,976
5,912
113
Pineville,LA
You will get all sorts of responses…

I run 5w40 all year, if its below 40 degrees I wont be on the tractor 🤣
 
  • Haha
  • Like
Reactions: 4 users

SRRGC1

Active member

Equipment
BX1870-1, BX23S TLB, RTV XG850, MX5100DT
Jan 6, 2021
212
75
28
Bloomsburg
I use 5w40 Rotella syn.in both my BX's. The Kubota dealer I worked at always used 15w-40 and that we sold.
 
  • Like
Reactions: 1 user

TheOldHokie

Well-known member
Lifetime Member

Equipment
L3901/LA525, B7200DT/B1630, G2160/RCK60, G2460/RCK60
Apr 6, 2021
8,206
4,130
113
Myersville, MD
windyridgefarm.us
Hi All, I tried searching and couldn't find anything on the forum. I'm curious.. living on the east coast mid Atlantic. I'll be using my BX23S for some snow removal in temps below 32 deg F. Most of my use would be spring through fall. Has anyone had any issues running 15W-40 below 32 deg? I know Kubota says 10w-30 below 32...or am I fine running 15W-40 all year round?
Virtually all automotive engine OEMs recommend a 10W or lighter oil when ambients are below freezing. That has been the engineering standard for 50+ years. Given the all season performance characteristics available with modern oils there really isnt any good reason to deviate from that standard.

Dan
 
  • Like
Reactions: 1 users

PaulR

Well-known member

Equipment
BX 23S -- 100 hours seat time so far
Aug 3, 2020
579
458
63
Hadley, MA
2020 BX 23S here
New England/Western Mass
10w-30

I would not hesitate with the Rotella 5w-40 either, as I know its an amazing oil.
15w-40 seems a bit too thick for me. just my humble opinion.
 
  • Like
Reactions: 1 user

michigander

Active member

Equipment
B2601
May 29, 2018
547
234
43
Northern Michigan
I run 10w-30 year around, if its above 80 degrees I won't be on the tractor. :ROFLMAO:

Winter time stored in heated in garage in the off chance I use it.
 

GreensvilleJay

Well-known member

Equipment
BX23-S,57 A-C D-14,58 A-C D-14, 57 A-C D-14,tiller,cults,Millcreek 25G spreader,
Apr 2, 2019
11,060
4,707
113
Greensville,Ontario,Canada
15-40, 666 hrs(3 years) so far, but tractor stored in 50* garage,so 'warmish' to start....
always gloplug for 3 steamboats everytime I start.
 

Henro

Well-known member

Equipment
B2910, BX2200, KX41-2V mini Ex., Beer fridge
May 24, 2019
5,634
2,802
113
North of Pittsburgh PA
15-40, 666 hrs(3 years) so far, but tractor stored in 50* garage,so 'warmish' to start....
always gloplug for 3 steamboats everytime I start.
15-40 in SW PA. Tractors kept in an unheated shed. 1800 hours & 19 years on the B2910, around 1400 hours & 1400 hours on the BX.

Rarely use my block heaters anymore. No issues here.

How many seconds in one glowplug steamboat?
 
  • Like
Reactions: 1 user

SDT

Well-known member

Equipment
multiple and various
Apr 15, 2018
3,206
1,011
113
SE, IN
Hi All, I tried searching and couldn't find anything on the forum. I'm curious.. living on the east coast mid Atlantic. I'll be using my BX23S for some snow removal in temps below 32 deg F. Most of my use would be spring through fall. Has anyone had any issues running 15W-40 below 32 deg? I know Kubota says 10w-30 below 32...or am I fine running 15W-40 all year round?
I use 15W40 year around in all of mine.

SDT
 
  • Like
Reactions: 1 user

lmichael

Active member

Equipment
Kubota G2160
Apr 23, 2021
595
241
43
Rockford IL area
I see no reason to use a 15W-40 when there is such an excellent 5W40 available in the likes of Rotella T-6. It has all the bases covered. Other than my cars which use 0W-16 and 0W-20 respectively it is the only oil I buy
 
  • Like
Reactions: 1 users

RCW

Well-known member
Lifetime Member

Equipment
BX2360, FEL, MMM, BX2750D snowblower. 1953 Minneapolis Moline ZAU
Apr 28, 2013
8,932
4,789
113
Chenango County, NY
I put 5w-40 Rotella T6 in my tractor yesterday. Have done the same for years year round.

I’m in central New York and use tractor with snowblower.

No block heater, and the tractor is stored in an attached, unheated garage.

The 5w oil makes cold starts SO much easier than 15w starts.

Fordtech is in Louisiana. If a warm-weather 5w start works for him, it works for me….
 

GeoHorn

Well-known member
Lifetime Member

Equipment
M4700DT, LA1002FEL, Ferguson5-8B Compactor-Roller, 10KDumpTrailer, RTV-X900
May 18, 2018
6,014
3,279
113
Texas
I see no reason to use a 15W-40 when there is such an excellent 5W40 available in the likes of Rotella T-6. It has all the bases covered. Other than my cars which use 0W-16 and 0W-20 respectively it is the only oil I buy
It’s my understanding that the wider the “spread’ of viscosity index…the more additive is required to produce it.
A 15W40 oil is a SAE 15 oil with additives to make it behave like an SAE40 when hot.
A 5W40 is a SAE 5 base oil with additives…. more additive is needed to accomplish that.

Additives wear-out. So if a SAE15 oil will work in your climate… I believe it’s probably better in most cases.

The BEST answer however will be in your Owners’ Manual and the use of any other weight will not be as good as that recommendation.
 

TheOldHokie

Well-known member
Lifetime Member

Equipment
L3901/LA525, B7200DT/B1630, G2160/RCK60, G2460/RCK60
Apr 6, 2021
8,206
4,130
113
Myersville, MD
windyridgefarm.us
It’s my understanding that the wider the “spread’ of viscosity index…the more additive is required to produce it.
A 15W40 oil is a SAE 15 oil with additives to make it behave like an SAE40 when hot.
A 5W40 is a SAE 5 base oil with additives…. more additive is needed to accomplish that.

Additives wear-out. So if a SAE15 oil will work in your climate… I believe it’s probably better in most cases.

The BEST answer however will be in your Owners’ Manual and the use of any other weight will not be as good as that recommendation.
No. The level of VI needed depends greatly on the type of additives used and the properties of the base oil. For example using synthetic base oil its possible to blend a 10W30 without any VI improvers whatsoever. Its not typically done because its more profitable to use a lesser quality synthetic and a small quantity of VI. A conventional 10W30 on the other hand will require the use of VI and at a much higher treat rate.

All said modern engine oils have minimum time in grade requirements and as long as you keeo up with your OCI your oil will remain in grade.

My twin turbo BMW is a oil shearing machine but Mobil 1 0W40 is a factory recommended grade and will stay in grade for 10K plus miles. In a 40HP low RPM diesel Rotella T6 5W40 it will go long past the scheduled OCI. The performance is so good Shell doesnt even blend a 10W40.

Dan
 
  • Like
Reactions: 1 users

B737

Well-known member
Lifetime Member

Equipment
LX3310
Jun 9, 2019
2,024
2,199
113
USA
what's in the book
lx3310
1635181904141.png
 
  • Like
Reactions: 1 user

GeoHorn

Well-known member
Lifetime Member

Equipment
M4700DT, LA1002FEL, Ferguson5-8B Compactor-Roller, 10KDumpTrailer, RTV-X900
May 18, 2018
6,014
3,279
113
Texas
…. In a 40HP low RPM diesel Rotella T6 5W40 it will go long past the scheduled OCI. The performance is so good Shell doesnt even blend a 10W40.

Dan
While Shell certainly makes excellent products…. I doubt that is the reason. I imagine their marketing research demonstrates that since 5W40 covers the regime in which 10W40 is used that the overlap doesn’t make it worth their time or capacity to offer a near-duplicate product. …but just my thought on that.

My wife’s Toyota uses Mobil 1, SAE 0W20 and schedules it at 10K miles also…but I use that 10K as a “cushion” and practice changes approximately every 5K….and don’t worry if I run over it a thousand. (It’s Toyotas’ stoopid filter system that pizzes me off…. It’s a plastic cap (broke on the second change) that requires one to FIRST open a plug to drain the filter…and to do that you have to insert a plastic tube which comes with the new filter and which often fails to properly engage. ….(and which doesn’t drain it completely so when you)…THEN remove the paper element (letting about. half the oil which SHOULD have drained to actually run down your arm and onto the floor)…. There’s a large O-ring that should be replaced but is often not included in the filter package depending upon the source…. Then you have to reassemble all that. Whereas a simple spin-on filter should have been used. Grrrr..

The second oil change I did the plastic cap had cracked and spewed 6 qts of expensive synthetic oil all over the garage before the oil-light came on (I was sitting in the drivers seat observing still…only took about 20 seconds to blow all that oil). :devilish:

And before you go thinking I might be inexperienced on oil changes…. I’m 70+ years old and a former TOYOTA TECH! :devilish::devilish::devilish:

Hello all new Toyota Owners!: Go buy a Dorman (brand) METAL filter cap for your Toyota from your local auto parts supply. (O’Reillys sells them for $17.)

Sorry for the thread-drift.
 
Last edited:

TheOldHokie

Well-known member
Lifetime Member

Equipment
L3901/LA525, B7200DT/B1630, G2160/RCK60, G2460/RCK60
Apr 6, 2021
8,206
4,130
113
Myersville, MD
windyridgefarm.us
While Shell certainly makes excellent products…. I doubt that is the reason. I imagine their marketing research demonstrates that since 5W40 covers the regime in which 10W40 is used that the overlap doesn’t make it worth their time or capacity to offer a near-duplicate product. …but just my thought on that.
???

That was the idea I was trying (apparently unsuccessfully) to convey.. Guess I need to work on my clarity of written thought.....

Dan
 

ac209

New member

Equipment
L3301 w/loader and 60" rotary mower, EA Grapple
Jul 1, 2021
5
10
3
Jacobson, Minnesota
I called the dealer that sold me my L3301. I live in northern MN and we have had mid 20s in the mornings already. I asked if I could use Rotella 5w-40 and he said I shouldn't and I should use 10w-30. I have read that so many people use Rotella 5w-40. My manual doesn't list that weight as an option. Are people using 5w-40 even if it's still under warranty?
 

UpNorthMI

Well-known member
Lifetime Member

Equipment
L3200, L3901, MX5800, SVL75-2, KX040
May 12, 2020
850
568
93
Up North, MI
I called the dealer that sold me my L3301. I live in northern MN and we have had mid 20s in the mornings already. I asked if I could use Rotella 5w-40 and he said I shouldn't and I should use 10w-30. I have read that so many people use Rotella 5w-40. My manual doesn't list that weight as an option. Are people using 5w-40 even if it's still under warranty?
I think the warranty question is a great question, why use a grade of oil that is not recommended by the manufacturer. I have not deviated from the recommended 10W-30 for cold climate use.

I did recently make my first warranty claim for an engine failure on a car, it was not a simple task, my claim was denied but eventually the brand agreed to 50% of the repair cost. Engine rebuild was $16k!
 

MrDave03

New member

Equipment
Kubota BX23s
Oct 13, 2021
2
0
1
07840
Thank you all for the feedback...I ended up calling several dealers in the tri-state. All recommended 10w-30 for NJ. I think the Rotella T5 10w-30 is looking good.. its a synthetic blend...and Wally world has it for $27 for a gallon. Where as Kubota conventional is $43 here.