Multiple oil specs

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I was tinkering around on the bike today and noticed the sticker on my frame with all the bike specs listed. Info listed two oil specs: 20w40 or 10w30. Why two specs?
 
Most mfgrs will have a oil weight use listed, for a given temperature range. Like under 40f, use the 10/30 wt. And over 40f to 100f ,use the 20/40 wt. Harley takes it farther stating 10/40 under 40f, 50 wt up to 80f, and 60 wt over 80f. They also state you can use 20/50 wt from 40 to 100, if it's more convenient.,,
 
owner's manual for my '06 Shadow lists 10w-40, but many folks use 15w40 without problems...I am using up a 'witch's brew' containing several 10w-40 motorcycle oils and 15w40 heavy duty oils

owner's manual for my 'new to me' '09 GZ250 lists 10w-40 JASO-MA rated oil as 'preferred', but gives a chart listing 10w30, 10w-40, 15w40, 15w-50, 20w-40, and 20w-50 with a warning to stay away from 'energy conserving' and 'resource conserving' oils; they understand that people will use what is available to them depending upon location, temperature, and riding conditions
 
Originally Posted By: outoforder
I was tinkering around on the bike today and noticed the sticker on my frame with all the bike specs listed. Info listed two oil specs: 20w40 or 10w30. Why two specs?


I don't know what kind of moto you own, but I'm guessing it's a Yamaha? Yamaha used those oil vicosities back in the 80's and for some reason has continued on to current motorcycles. For instance, my 86 Yamaha FZX700 recommends 10W30 & 20W40, along with my 2007 FZ1 and many other current production Yamaha motorcycles. They used to do this I believe to help achieve greater shear stability due to a decrease in VII's (especially when compared to older formulations of 10W40 & 20W50), and the fact that their Yamalube was one of the fewer oil manufactures that produced the oils in those viscosities and their requisite certifications which helped bolster sales and the use of their lubes.

Interestingly enough, Yamalube no longer produces motorcycle oils in those two viscosities even though they continue to recommend them in their manuals. If you have your motorcycle's service manual you'll find they give you a much wider spread of viscosities to use under varying temperatures. My FZ1 for instance only recommends 10W30 for extreme cold start-up conditions, and also states the use of 10W40, 15W40, 20W40, and 20W50 to be used for more average riding ambient temperatures.
 
yamaha still lists 20w40 in their manuals, today, in 2014.

ya know why?

they sell yamalube 20w40 for the low low price of 8.99qt

yet i can get a gallon of SRT 15w40 for about double that.
 
Originally Posted By: sunruh
yamaha still lists 20w40 in their manuals, today, in 2014.

ya know why?

they sell yamalube 20w40 for the low low price of 8.99qt

yet i can get a gallon of SRT 15w40 for about double that.


That's interesting! I know Yamaha still recommends the use of 20W40 in many of their bikes ranging from super-sports to their Star lineup, but have you still been able to track down recent stock of their MC approved 20W40?

I talked with a friend that owns a local Yamaha dealership, and he's not been capable of obtaining Yamalube's 20W40 for quite some time, except for their Marine Outboard engine oil in that specific viscosity; plus Yamaha doesn't list an MC approved 20W40 on their Yamalube website also. I wonder if it could be older stock or they came across some surplus in one of their warehousing/distribution centers? Interesting coincidence none the less!

https://www.yamahapartsandaccessories.com/yamalube-products/engine-oils?ls=Yamalube
 
The two specs means the Engineers back at the factory have deemed
that your bike can meet your mileage expectations with either a 30
or 40 weight... the only difference will be the amount of HP you
will enjoy... the higher the oil viscosity the more HP it takes to over
come the oil drag...
 
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its on the shelf at both of the big dealerships around here.

dont mind the dust on the bottles though
grin.gif
 
Quote:
Harley takes it farther stating 10/40 under 40f, 50 wt up to 80f, and 60 wt over 80f. They also state you can use 20/50 wt from 40 to 100, if it's more convenient.,,


May want to check into the Harley recommendations a little further...the 50w thru 60wt you describe are rated "Good" by Harley whereas the 20w-50 is rated "Best" for the operating temp's you posted.
 
Their recommended oil wt. is for ease of starting in those temperatures. So if you live in a hot area like Texas, or Arizona, you won't notice any difficulty starting your bike if you run straight 50 or 60 wt oil. The 20/50 wt recommendation covers all bases, but has been known to create more motor noise. That is more of a annoyance to the riders then the motors.,,
 
yes if your ambient is say 65F or more, sae 50wt is fine for startup. hit 80f for ambient startup and sae 60wt is no problem either.
not saying that those are hard numbers, but be smart about it.
sae 60wt is pretty darn thick stuff.
 
haha You should hustle them for a discount on that dusty oil, you'd be doing them a favor by taking it off their hands!
 
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