Oil for colder weather 5W30 vs 5W40 vs 10W30 vs 10W40 | GTAMotorcycle.com

Oil for colder weather 5W30 vs 5W40 vs 10W30 vs 10W40

Phoenixfire99

Active member
For riding in colder temperatures would you switch oil viscosity?

When would you use

-5W30
-5W40
-10W30
-10W40
?

I ride all year and if the roads are clear I ride all the way down to about -10C. My bikes are also in a non heated garage where the temp inside is about 2C warmer than outside.

I’ve always used motul 10W40 full synthetic but I’m wondering if it would be better to switch to a grade that flows easier in the cold.

Any comments?
 
Manual says
10W30 for -10 to 20 C
20W40 for 10 to 40 C

My main curiosity is what is the difference between 10W30 vs 10W40? If they’re both full synthetic why wouldn’t you want the larger range with 10W40? Is there a cost / quality variation?

And has anyone used 5W30? Is 5W better for colder weather?
 
Easier on moving parts during cold weather start ups. 0W a tad better.


Awesomeness........another oil thread.
... but that's not how it works. It has to be designed to use that thin oil, and will need a small diameter big end bearing and small clearance, which OP don't got.
Start here to understand oil viscosity:

Not a big fan of BOB... I blame him for everybody using Rotella oil and that's just wrong. Somehow people out there in internet land got convinced Rotella is GOOD oil, and I blame him. I'm probably wrong, but I'll hate him for it anyway.
Gives me somethin' to do. I'm bored. old man yelling at cloud emoji here

...BUT ANYWAY... the only time you have to even consider going to thinner oil when it gets cold is if the starter can't turn over the motor fast enough to start the motor... and if that's your problem I'll BETCHA your problem isn't oil. It hasn't been THAT cold.
MOSTLY, if the motor starts, you're good to go. Motorcycles have a displacement oil pump and will pump frozen grease with sand in it, as long as it's turning. The oil in the system heats up from friction from getting rammed through the oil pump and all the small gaps we push it through, almost instantly. Your oil problem at startup is oil pressure because all the oil gaps are huge because all the metal has contracted because of the cold , NOT oil temperature or viscosity. You're not doing the motor any favours by starting it in the cold, but oil temperature isn't the issue.
If it gets cold enough that have to worry about oil: it's too cold to ride. The bike will go, you'll freeze your nards. If your properly tuned bike, with a fully charged battery, fresh fuel, with the "average user" oil in the crankcase doesn't start when it's cold, it's because the people that designed your motorcycle think it's too cold to ride and they think you're an idiot, and you should go inside where it's warm and get a nice hot cup of tea. You need to sit by the fire. What were you thinking? Have you looked out there?
It's a design "feature" (that's not included on euro bikes...their designers are looking down their nose at ya even when it's warm and sunny).
... unless, of course, you have a kick start bike. Then everything I just said goes out the window and you have to move to the top of a hill... and you'll need to find a job at the top of a hill....
 
You're trying to bait someone into defending Rotella. Well, I'm not falling for it this time
 
RTFM. But if you insist on going outside of what the M says, or if you have no choice but to do something else due to lack of availability ...

The first number is indicative of the viscosity grade when cold (cold start-up). The second number is indicative of the viscosity grade when hot (normal operating temperature). The absolute viscosity when cold is always going to be higher than the absolute viscosity when hot, that's why I'm saying "viscosity grade" and not "viscosity". So then ...

If you are going to make a mistake with the first number, make a mistake on the side of it being easier to pump. Smaller number is OK. The oil pump is always going to be able to pump it because that's the limiting factor when cold.

If you are going to make a mistake with the second number, make a mistake on the side of it not squeezing out of bearings or squeezing out of cam-follower interfaces and allowing metal-to-metal contact. Bigger number within reason is OK.

The bigger problem you are probably going to find, is that your M probably (disclaimer: we don't know what bike you have) wants oil that meets JASO MA (for wet clutches) and is not "energy conserving", and finding that in a Xw30 could be challenging.

I have a high-mileage bike that is an oil burner due to worn/incorrect cylinder wall finish that is too expensive to put right (long story) and for the last 40,000 km, my selection of oil has purely been whatever is cheapest. Nothing else. Guess what ... it hasn't blown up, and it continues to use oil at roughly the same rate. Nothing makes any difference. Your mileage may vary.
 
Does anyone remember the days of putting hot coal under your Harley's crankcase of SAE30 and VW's during cold temps....
 
Does anyone remember the days of putting hot coal under your Harley's crankcase of SAE30 and VW's during cold temps....
Hey slow down young fella, don’t choke on your food
 
... but that's not how it works. It has to be designed to use that thin oil, and will need a small diameter big end bearing and small clearance, which OP don't got.

Not a big fan of BOB... I blame him for everybody using Rotella oil and that's just wrong. Somehow people out there in internet land got convinced Rotella is GOOD oil, and I blame him. I'm probably wrong, but I'll hate him for it anyway.
Gives me somethin' to do. I'm bored. old man yelling at cloud emoji here

...BUT ANYWAY... the only time you have to even consider going to thinner oil when it gets cold is if the starter can't turn over the motor fast enough to start the motor... and if that's your problem I'll BETCHA your problem isn't oil. It hasn't been THAT cold.
MOSTLY, if the motor starts, you're good to go. Motorcycles have a displacement oil pump and will pump frozen grease with sand in it, as long as it's turning. The oil in the system heats up from friction from getting rammed through the oil pump and all the small gaps we push it through, almost instantly. Your oil problem at startup is oil pressure because all the oil gaps are huge because all the metal has contracted because of the cold , NOT oil temperature or viscosity. You're not doing the motor any favours by starting it in the cold, but oil temperature isn't the issue.
If it gets cold enough that have to worry about oil: it's too cold to ride. The bike will go, you'll freeze your nards. If your properly tuned bike, with a fully charged battery, fresh fuel, with the "average user" oil in the crankcase doesn't start when it's cold, it's because the people that designed your motorcycle think it's too cold to ride and they think you're an idiot, and you should go inside where it's warm and get a nice hot cup of tea. You need to sit by the fire. What were you thinking? Have you looked out there?
It's a design "feature" (that's not included on euro bikes...their designers are looking down their nose at ya even when it's warm and sunny).
... unless, of course, you have a kick start bike. Then everything I just said goes out the window and you have to move to the top of a hill... and you'll need to find a job at the top of a hill....
Rotella user here(y).

Been using it in bikes since the late 70's, never had an oil related failure on a bike. I don't race them on the track, but I have been known to work them hard and pile up the miles - my little 250 ninja piled up 120,000 km in 5 years and ran like a top when I sold her - Rotella her whole life.

I don't think Rotella is magic -- it's just economical and comes in blends suitable for motorcycles. Once or twice a year I find CTC and Walmart put it on sale from $70-90 for a 20l pail - I use 2 pails a season. If I saw a difference first hand between motorcycle specific and Rotella, I change -- but I haven't see a reason to change so I'll save the $600 a year using Rotella.
 
ice bike yz450f, -10c starts 2 kicks with 0w40. same temp with 10w40 cant even tow it to start it. just wont roll over free enough.

You're probably using that engine outside of its original design parameters. LOL

0w40 is probably synthetic oil. 10w40 might or might not be.

Not bike related but my understanding is that all of the Xw20 and Xw16 engine oils that many newer auto engines specify, are synthetic or synthetic-blend.
 
Hey slow down young fella, don’t choke on your food
That was from my Dad who always complained about 6 volt electrical systems in his vehicles in the '50s and moreso during the winter months.

We lived in the country and to get to work on a winter morning he would fire up lumps of coal under his VW truck the night before. On some really tough nights he would drain the crankcase oil and bring it inside for the night then pour them back in mornings.

It all came back to me when I worked winter construction in Calgary having to lay down pads of coals then fire them up so we could break gound for utility installs the next day.
 
We still tarp in a lot of equipment and put frost fighters on them to get it to fire up
 

Back
Top Bottom