Rotella T5 synthetic blend diesel.

[John Schmidt]

It's 10w30, any reason why I can't use it in the Valk? It was $20.99/gal. compared to almost $45 for four qts. of Valvoline syn 10w40 "motorcycle oil."

[Pete]

None that I know of   ---    but  ----
Under you temperatures I prefer 15w40 Mobile 1 at $22 to $26 for 5 quarts.

[gordonv]

Instead, Rotella T6 full synthic and 10W-40, $21 at wally mart.

[old2soon]

          Mobil 1 15/50 full synthetic at wally wurld 23  25 bucks for 5 qt jug. RIDE SAFE.

[Jess from VA]

Everybody says what they use, but don't answer your question.

I'm no oil guy, but I'd be reluctant to vary far from OE recommended 10w40.

I've run a lot of Shell Rotella T6 5-40 ($19 a gallon here), but it's pretty thin, and some important additive has been reduced in it lately. (see another recent thread) 

FL gets pretty hot, and it seems the 40wt part of 10w40 might be pretty important in that heat.

That's all I got.   (except the obvious advice to avoid any synthetic with friction modifiers to damage a Valk wet clutch)   The other key word to avoid besides friction modifier is extended life.

[cookiedough]

I think the 40 number is more important than the 5w or 10w or 15w number.  Not 100 percent sure, but the 40 is number when engine fully hot warmed up while the 1st number 5w or 10w or 15w is initial cold startup number.   In Florida or hotter climates I would go with 10w or 15w but not 5w but here in WI since I drive more 50 degree temps than 90 degree temps,  I think 5w is fine.

I would be more apt to run 5w-40 or 15w-40 (or best 10w-40) over 10w-30.  

I use to run amsoil 10w40 cycle oil at 11.50 per qt. but after getting a few more cycles last year,  I switched last year on all of them to rotella t6 5w-40 and all ran fine last year.  It is a tad bit thin pouring out though at 5w weight  being rotella t6  vs. what was used Amsoil 10w-40 prior.   A few weeks ago I even put in in rotella t6 5w-40 in my kids 2005 yamaha fjr1300 but no idea how it runs until next spring vs. I think owners manual said 15w-40.  Only started cycle a few times though not running down roads or shifting gears since under 32 degrees out and winter not driving on all salt roads nearby.

My 250cc scooter is suppose to get 15w-40 but for 8 years now owning it I have used amsoil 10w40 or rotella t6 5w-40 but that is just belt drive NO gears or clutch so pretty much anything will be fine in it am sure.

I need to change rear gear oil though on all cycles next spring guessing scoot NEVER changed since new 2008 and both Valks have been at least 5 years or so while fjr1300 who knows but only has 18K miles on it since new in 2005.  Did Coolant change on both Valks this year even though I think once every 5-6 years is fine.

[sdv003]

I've read bobistheoilguy.com a few times, and if I understand it correctly, I don't think it will matter whether you run XW30 or XW40 weight oil, assuming your cooling system is in good operating condition. The service manual says that 10W30 weight oil is OK, up to 90*F or so.  Since the engine runs at temps up to 210*F under normal conditions no matter what the ambient temperature is, then XW30 oil must be OK.  XW40 is a little thicker at operating temperatures, but shouldn't be "necessary" unless you can't maintain the operating temperature at or below 210*F during the hotter portions of the year.

I run 5W40 synthetic year round.  It gets hot here in the desert in the summer, but *most* of the time, even at the height of summer, the engine is just at operating temperature.  On occasion, when I'm at a light in the summer, the temp gauge will hit 230*F before the fan starts having an impact, but the XW40 weight oil should be able to handle that for a few seconds every once in a while, especially a synthetic.  The 5WXX weight oil makes sure that the engine is getting good lubrication when it's 45*F in the garage during the coldest days.  Personally, I think the cold number is way more important than the hot number, unless there are extenuating circumstances.

That's my 2 cents.

[¿spoom]

FYI, Menard's here in the Midwest currently has Rotella T6 5W40 syn in gal. jugs on sale for $18.99. The 3 jug cases were on sale also, but I forget the price.

[cookiedough]

FYI, Menard's here in the Midwest currently has Rotella T6 5W40 syn in gal. jugs on sale for $18.99. The 3 jug cases were on sale also, but I forget the price.

so does farm and fleet store around 20 bucks also regular pricing though and with sale pricing have seen 17.99.  EVERY year the past few years I have been seeing up to 4 gallon jugs of rotella t6 yearly with 7 dollars each per mail in rebate.  That is good since I now use rotella t6 on 2 ATVs and 4 cycles but do not change the oil yearly on the ATV's since only put on usually 500 miles or so tops per year on them.

I will be downsizing next year to only 1 ATV selling 1 and also selling 1 to maybe 2 cycles, not sure on that one yet.  I figure I ride all 4 of my cycles depending on my mood of the day (except the one going to sell next year) so why sell them if not costing me anything besides gas.  Does not cost me anymore on insurance since for some reason if I sell 2 of the cycles, the rate stays the same something about the MORE cycles you insure, the MORE off each of the cycles for rates.  Does not make sense to me, but not complaining.

[psckam]

w=winter

[John Schmidt]

Returned it and picked up a jug of 15/50 Mobil 1. Bike is all back together and riding it. Should be good for another 20 years, then I'll decide if I want to keep riding.  

My Book tells me they have pretty fancy streets where I'll be riding by then.

[Avanti]

Riding it, a way good feeling.

[Alberta Patriot]

I think the 40 number is more important than the 5w or 10w or 15w number.  Not 100 percent sure, but the 40 is number when engine fully hot warmed up while the 1st number 5w or 10w or 15w is initial cold startup number.   In Florida or hotter climates I would go with 10w or 15w but not 5w but here in WI since I drive more 50 degree temps than 90 degree temps,  I think 5w is fine.

I would be more apt to run 5w-40 or 15w-40 (or best 10w-40) over 10w-30.  

I use to run amsoil 10w40 cycle oil at 11.50 per qt. but after getting a few more cycles last year,  I switched last year on all of them to rotella t6 5w-40 and all ran fine last year.  It is a tad bit thin pouring out though at 5w weight  being rotella t6  vs. what was used Amsoil 10w-40 prior.   A few weeks ago I even put in in rotella t6 5w-40 in my kids 2005 yamaha fjr1300 but no idea how it runs until next spring vs. I think owners manual said 15w-40.  Only started cycle a few times though not running down roads or shifting gears since under 32 degrees out and winter not driving on all salt roads nearby.

My 250cc scooter is suppose to get 15w-40 but for 8 years now owning it I have used amsoil 10w40 or rotella t6 5w-40 but that is just belt drive NO gears or clutch so pretty much anything will be fine in it am sure.

I need to change rear gear oil though on all cycles next spring guessing scoot NEVER changed since new 2008 and both Valks have been at least 5 years or so while fjr1300 who knows but only has 18K miles on it since new in 2005.  Did Coolant change on both Valks this year even though I think once every 5-6 years is fine.

I like to see it this way:
When the engine is cold, only the "W" (eg. 5W) number matters.
When the engine is hot, only the second number matters.
Synthetic oils are much better at maintaining viscosity at high temps. It is also much better at resisting "shear" compared to dyno oil. M/C engines are hard on oil because of the transmission sharing the same oil. The extreme pressure between gear contact surfaces breaks down oil faster than engines that have a separate tranny.
Re: Areas like Arizona...using  50 instead of 40 is probably a good idea.
5W oils get lubrication to critical parts just a little bit faster...especially frigid morning cold starts. If someone came up with a 0W 50 Synthetic...I would use it...no hesitation!!