Without boring anyone with the details of "why", I've had some Honda Dino 10W-40 in my '08 CBR1000RR since I got it several weeks ago(And yes, I've already done one oil change at about 80 miles and am now up to about 160 and ready for the second oil change to a lower viscosity).

Anyway, I've ridden a couple days/mornings where the temps have been in the low to mid 40's and my manual calls for 10W-30 in that temp range(it shows the transition to the 40 weight at around 50-60 degrees).

My question is, is starting up with that oil under those conditions really going to hurt the engine? I always thoroughly warm the engine up before riding and go easy until the engine is fully up to operating temps. I'm going to go grab some 10W-30 ASAP but had the 40 weight to use and couldn't resist riding...now I feel a bit guilty...any opinions?

Get your hands on some Mobil 1 10W-40 motorcycle oil and run it year round without any problems.


https://www.mobiloil.com/USA-English/MotorOil/Oils/Motorcycle_Oils.aspx


Nice bike.

Or even M1 10-40HM - a lot less expensive, and gives excellent results.

In the meanwhile, don't worry about it. The "10" number is what matters in cold weather...

I don't think the oil is worn out at 80 miles or 160 miles for that matter.

oldwolf,
depends on the oil. some 10w40s i can kill in 80 miles.

actually now that i write that. i have yet to have a 10w40 stay in grade in 80 miles.

he certainly is not hurting anything.

That's because you have the Mother of All Oil Munchers!! We're talking about normal bikes here!!

I switch to a 15-40 HDEO when the weather gets colder. I know its ok since my bike originally called for a 20w-40 Yamalube. In summer I run a 20w-50 bike oil though.

You're okay ... by a wide margin you're okay.

The "10W" part of that is what indicates the cold flow properties, not the "40". A 10W oil is good down to the teens. It's when you're cold starting in even colder temperatures that you have to consider even better cold-flow oils.

The "40" indicates the operating temperature properties of the oil. That means at temperature the oil behaves like a 40 weight in terms of flow.

The low 40's poses no issues whatever.

FYI, they get that "best of both worlds" flow properties by starting with a thinner oil and adding "viscosity improvers" (VIs). The trouble with that is they tend to shear down more quickly.

Perhaps you've read on this site people talking about "straight weight" oils ... a "straight 40 weight"? That means it's a "true" 40W ... no VIs, great shear protection, not good cold flow properties.

Synthetic 5W-40's take an even thinner oil -- hence the even better cold flow properties -- and add even more VIs. They tend to shear as well. But if you're doing cold starts or very high heat conditions, synthetics tend to work well.

I live in Tucson where in the winter months the temperatures are on average in the low 40's, and in the summer the highs go to about 110. I run HDEO 15W-40 year round.

And I don't worry at all.

Sleep like a baby.

The stuff has "good enough" cold flow properties for my neck of the woods and "good enough" temperature protection for a water cooled bike even in the Tucson desert heat.

Oh, and by the way ... you have to understand that our friend "sunruh" is a sadist on oil. The guy is cruel beyond words. He revels in beating oil within an inch of its useful life.

But we still love him just the same.

I run redline 20w50 all year. Just let the bike sit for 2-3 minutes before you ride off.

GREAT replies! I always learn something new from this forum. I wonder why the distinction in the owner's manual then...seems odd they would specify a 10W30 transition at about 40 degrees when I don't see many people running that in the "real" world. Thanks for all the replies so far!

My bike wont even run right on the highway at below 40. I tired it, but it overcooled and ran like [censored]. I switch to 40 weight below 60 for the two months at the end of the riding season.

I have a 27 yea old Honda Goldwing that I use thruout the winter.It's kinda like a rat bike lookswise. It was originally from Ohio now in jersey. Don't know what or how it was treated in it's previous life. I run 15/40 rotella, delo 400, or delvac diesel oil in it.What's ever on sale. I'll use it at temps as low as 12, and haven't had any starting problems. It's kept in a unheated garage and is run at least once a week. The longest it has sat is about three weeks.What I do tho, is block off about a third of the radiator, so I can get the motor up to operating temp.It has 45k miles on it sounds great and doesn't use any oil between 3k changes. The oil is passed thru the motor and trans, so it gets a work out.If you use a battery tender, It should fire right up and with a decent warmup, that bike will out live you.,,lol.

In cold weather I can unplug a temp sensor on my radiator and it'll just shut off the cooling fan completely. I never gets above summer operating temps.

I run mine in the winter on the highway in the high 30's to mid 40's with either 10W40 or 5W40 syn. Runs a little rough cause it is carbed for a few minutes but once warmed up runs like normal