15W-40 instead of SAE 30 or 10W 30 for lawn and riding mowers.

[Engineer]

I have three lawn mowers and the oil specs for those are from the manual as below,

Husqvarna Push Mower - SAE 30 preferred, 10W 30 for varying temp zones, 15W-50 Synthetic for best performance
Cub Cadet XT1 - SAE 30 or 10W-30
Honda HRN/HRX - 10W-30 preferred but can you use SAE 30.

I have seen here in various threads where people say SAE 30 is on its way out and 15W-40 is the new SAE 30. It is hot where I live with temperatures nearing 100 during summer and I am wondering if I can use 15W 40 on these machines.

I would like to hear from people who have switched to 15W 40 on their small engines even though that grade oil is not a recommended oil in their factory manual.

Is this oil you use regularly on your machines, or do you use it just during summer and switch back to a lower grade oil?

I am about to change the oil on my new Honda mower after the first 5 hours and considering the temperatures here am wondering if I can start using 15W-50. I did buy the Honda 10W 30 oil when I bought the mower, but I am thinking that the 15W 40 would be a more heat tolerant oil. Off the bat, I think I can use it on the Husqvarna as it says I can use it, but wondering about the Honda and Cub Cadet.

Any thoughts and experiences are appreciated.

 

[Brian123]

With Temps near 100 degrees a 15W-40 would be fine. What are the lowest temps that you will be using these Mowers?

Do you have an Infrared Temp Gun?

 

[Cruisin'n5thgear]

I was wondering the same thing. I'll be interested to hear the opinions on this thread.

 

[Jetronic]

you can always go up, but the higher the viscosity the harder to start. KV40 would be the relevant metric here

 

[Engineer]

With Temps near 100 degrees a 15W-40 would be fine. What are the lowest temps that you will be using these Mowers?

Do you have an Infrared Temp Gun?

I do and the lowest when I use the mowers is probably around 60 degrees.

 

[levi]

I've used 15W40 in my Snapper Ninja 6.5 HP self-propelled mower for years. No issues.

Doubt your mowers would ever notice if you did the same. And if they did notice, they wouldn't tell anybody.

 

[Brian123]

I do and the lowest when I use the mowers is probably around 60 degrees.

With the lowest temp being around 60 Degrees, you should be fine using 15W-40. Take some temp readings of your Oil Filter on the Cub Cadet with what you are using now, which I am guessing is 10W-30, and then again if you go to 15W-40

I have a Cub cadet XT1 that I am breaking in on Shell Rotella T4 10W-30 and in 94 Degree weather I saw 210 Degrees on the Oil Filter when I aimed the Infrared Gun at it.

 

[BHopkins]

I have not tried 15W-40, but I have switched my lawnmower and snow blower to 0W-40. I can't tell much difference in the snow blower, but I sure can with the mower. It runs much quieter with the 0W-40 than it did on the 30HD.

I selected 0W-40, because I already use it in one of my cars, so I was able to reduce the variety of motor oils I have to keep on the shelf. But I would have no problem using 15W-40 in the mower. Not to sure if I would use it in my snow blower.

 

[gman2304]

would like to hear from people who have switched to 15W 40 on their small engines even though that grade oil is not a recommended oil in their factory manual.

My JD LX188 manual recommends 30 wt or 5w30. I’ve used Rotella T5 in my Kawasaki 501V for 15 years. In fact I use it in all my 4 stroke lawn equipment even my tiny Honda 4 stroke tiller. NEVER a problem. All my equipment is stored in a garage but if it were in a pole barn in N.Dakota, I’d reconsider my choices!

 

[kschachn]

Film thickness prevents wear. As temperature goes up the film thickness goes down. This is a piece of air cooled equipment. MOFT is your friend.

I use a 40-grade oil on all my OPE. It’s the same 0W-40 I use in my old Sienna. But I could use the same oil I use in the Tiguan because the VW 504 00 approval guarantees a minimum 3.5 HT/HS. Winter rating is absolutely irrelevant for my equipment, except for the snow thrower.

 

[fantastic]

I have used 15w-40 in my mowers. currently using 5w-40 HDEO. HDEO is going to have a high dose of additives over a 10w-30 PCMO. I've been talking about this w/another member here trying to weed through our options for air cooled machines. If you can run a 30 & 50 you can run a 40 grade oil.

 

[Engineer]

With Temps near 100 degrees a 15W-40 would be fine. What are the lowest temps that you will be using these Mowers?

Do you have an Infrared Temp Gun?

I do and the lowest when I use the mowers is probably around 65 degrees.

Film thickness prevents wear. As temperature goes up the film thickness goes down. This is a piece of air cooled equipment. MOFT is your friend.

I use a 40-grade oil on all my OPE. It’s the same 0W-40 I use in my old Sienna. But I could use the same oil I use in the Tiguan because the VW 504 00 approval guarantees a minimum 3.5 HT/HS. Winter rating is absolutely irrelevant for my equipment, except for the snow thrower.

Your VW is probably spec 'ed to run on 40W. But, on others will that oil be heavy to pass through the oil channels in the engine? And do the oil filters designed for 30W still allow 40W oil to pass through without resistance? Because I have a Cub Cadet with oil filter.
For paddle wheel splash lubricated small engines I think it could be fine.

 

[92saturnsl2]

15w-40 can be considered a universal OPE oil for air-cooled engines IMO. Robust additive package that isn't neutered compared to the latest SN/SP (spark ignition only) oils. It will work fine in any OPE application except perhaps snowblowers.

There has been a trend over the last decade or more in moving toward a universal 5w-30/10w-30 from the major engine manufacturers. It was eye opening to me that Kawasaki issued a bulletin suggesting 15w-50 for their engines after tons of folks (and likely warranty claims) reporting oil consumption issues with a 30 weight.

 

[4WD]

My CC LT42 is 18 months old. Have run 10W30 M1, 0W40 PP, and
now 15W40 Delvac - mowed twice - runs great …
(Just hogged tall grass and crud from storm) …

 

[Lawnman23]

I run Rotella T5 15w-40 in every piece of OPE I have, except for the snowblower. That still gets 5w-30 until I use up the rest of what I have. After that, it will be a 0/5w-40.

Lawn-Boy and Echo chainsaw get Royal Purple HP 2-C because two-stroke.

 

[JavierH19]

I've used a half dozen different 15w-40's I find on sale in all my ope and older trucks. Picked up 5 gals of mag1 last week just to refill the stash and try something different. Any will work fine.

 

[Plumb Bob]

I use HDEO 15W-40, or any Euro with A40/229.5

 

[oil pan 4]

Those hard work air cooled engines such as riding mowers, pressure washers and generators need at least an oil that ends in 40.

 

[Engineer]

I went to Walmart and got the Super Tech full synthetic 15W-40 and changed it on my Husqvarna. It ran fine but I haven't mowed the grass yet. The sound from the exhaust is different. Seems like it has more oomph. But I will mow the grass tomorrow with it and see how it works. But my Husqvarna can use 15W-50! as per the manual. First time I have used it in the last 9 years.

Honda on the other hand... brand new and afraid to experiment. I also have a Firman suitcase generator which is spec'd for 10W 30.

Here is the oil spec for the Firman generator. I see it has 10W 40. So I guess I can use that 15W-40 on that as well?

 

[fantastic]

I went to Walmart and got the Super Tech full synthetic 15W-40 and changed it on my Husqvarna. It ran fine but I haven't mowed the grass yet. The sound from the exhaust is different. Seems like it has more oomph. But I will mow the grass tomorrow with it and see how it works. But my Husqvarna can use 15W-50! as per the manual. First time I have used it in the last 9 years.

Honda on the other hand... brand new and afraid to experiment. I also have a Firman suitcase generator which is spec'd for 10W 30.

Here is the oil spec for the Firman generator. I see it has 10W 40. So I guess I can use that 15W-40 on that as well?

View attachment 230280

Generators I prefer a 5w-40 since I use them in all temps at times. I did test that ST oil if you want to know it's additives or want to do UOA. Link is in my signature.