You will find that 20W50 is not even in the Honda owner's manuals anymore! These days it is just 10W40 and 10W30 for 3-season, and 5W30 and 0W30 for colder weather.

I would however run 20W50 during summer in a very hot climate, like if I were in Las Vegas or Phoenix......and I was stupid enough to ride when it was 115 degrees....

A good basic oil article in case you haven't seen it before: http://www.thumperfaq.com/oil.htm

 

I am an oil nut. [img]i/expressions/face-icon-small-smile.gif[/img]
Which is why I wanted to check to see if anyone here runs 20w50, I believe in running it in everything, unless the machine requires a lighter viscosity oil.
I think a good rule of thumb would be 10w40 winter, 20w50 spring through fall.

 

Depends of course on where you live, plus the type of oil.

A lot of the popular ideas we have about oils were shaped during a previous generation when all they had was petroleum oils. Back then, when an oil didn't hold up, all you did was increase the bulk viscosity. For example, if you started out with a 50 weight and it sheered down to 30, you were still ok, where if you started out with a 30 weight and it sheered down to 10, you were in trouble.....

Now, there are synthetics that can combine great additive packages and very high film strengths (HT/HS), with fairly thin oil viscosities. This means that you can get better performance because of lower fluid drag and easy pumpability, yet in the areas where it matters most like in bearings and on the cylinder wall you can still have great protection. Also, a lighter oil will pump faster, so it is going to circulate more quickly so it will cool better, not to mention that oil pressure will come up more quickly at start up (which is actually when most wear occurs).

I live in the southwest where summers are very hot and winters are mild, at least at low altitude (not necessarily so in the mountains however!). For years my warm weather oil was Maxima Extra 15W50 and my winter oil was 10W40. Now, I have switched to RedLine, and my summer oil is 10W40 and my winter oil 10W30. That said, I'm not out riding when it is over 90 degrees in summer, and if I were in the mountains and it was extremely cold, I might run a 0W30.

 

The low pour point is a huge benefit of synthetics... you can have the best of both worlds, higher viscosity for better protection and sheer strength, and good pumpability in cold weather. If a 10w40 or 20w50 is recommended I run 20w50 unless it is really cold.

 

I actually once didn't have time to change out the 15W50 that I was running, before a cold weather trip to the mountains. This was in my Rancher 350, and I noticed the difference! I was down on power, and I could definitely feel the added fluid drag from the thick oil....

 

Could also be due to the dense air charge the engine is getting, tends to lean out the mixture even further which can reduce power if it's already set lean.

 

I adjust my mixture on the fly with the Thunder Products TPI Valve. My typical mountain rides start at 4,000' and end at around 11,000'...all in one afternoon's ride! I have used the TPI system for years...and it works great.

So no, it was the thick oil at cold temps...not the jetting! This is a ride I had done a hundred times before, summer and winter.

 

Same brand and type of oil? Or was one synthetic and one not?
The real world difference in drag should be minimal and hardly noticeable.

 

<div class="FTQUOTE"><begin quote>Originally posted by: HunterTRX350D

Same brand and type of oil? Or was one synthetic and one not?

The real world difference in drag should be minimal and hardly noticeable.</end quote></div>

I was running Maxima Extra 15W50. Normally, I would have run Maxima Extra 10W40. Keep in mind that this 10W40 is spec'd at only 12.5 cSt at 100 degrees C, which is right smack on the borderline between 30 and 40 weight. Maxima calls it 10W40 for marketing purposes, but they could just as easily have called it a 10W30 by just dropping it to 12.49 cSt. My point is...this is a very light oil compared to any other 40 weight on the market.

On this particular day, it was snowing and there was significant wind chill, The cuttoff for a 50 weight in my owner's manual is 32 degrees F, and I was significantly below that!!! This 15W50 oil is spec'd at 17.42 cSt at 100 degrees C, which is a significantly more viscous than the 12.5 cSt of the oil I am comparing it to.

http://www.maximausa.com/produ.../maxum4synthextra.asp


The fluid drag I experienced was real....and not just my imagination! 20W50 is no "all weather" oil, by any means!

 

Normally I would say you are right, 20w50 should be avoided in cold temps. But you are running synthetic so that shouldn't be much of an issue, especially once the machine is warmed up. Yes you might be able to feel a small difference, maybe even hear it.. too, though personally I wouldn't switch out to a light weight oil unless it got down into the 40's or below.
You must be in a really cold climate, so you really don't have a choice but to run the lower viscosity. I am lucky because here in Texas it rarely even freezes during winter. [img]i/expressions/face-icon-small-smile.gif[/img]