HDEO + VII for Harley

[rksk]

This is my first post as a new member, although I have been viewing for some time. This site is great, and find it very informative, and also very addictive!

Now to my question. I have a 92 FXRS (Harley) with an Evolution engine that specs a 20W-50 oil. I really like the properties of HDEO, but I am concerned about the 15W-40 viscosity, which is too light for this application and the warm/hot temperatures of North Texas. Is it feasible to boost the viscosity of a 15W-40 HDEO (dino) to an approximate 20W-50, by adding a VII. I have about 10 gallons of mixed fleet 15W-40 HDEO (Rotella, Delo 400, and Texaco USRA) and several different VII's (but would prefer to use STP blue bottle). I would love to use this HDEO in my bike if I can blend something that will work well.

If this is feasible, approximately what mix ratio of STP to 15W-40 HDEO would I need to come close to a 20W-50 (in fluid ounces of STP per quart of 15W-40 HDEO)?

If this subject has been addressed previously, I apologize, but I could not find it.

Thanks!

 

[Steve S]

I would say no to adding the STP to increase the viscosity of the oil.

 

[Steelhead]

mix 3:1 with 70w Twin Power single weight oil. most Harley/Chopper shops carry or will order Twin Power. no VIs.

VIs are not good in an air cooled V twin

 

[rksk]

Thanks for the replies. Can you educate me on why a VII should not be used in this application. I am a noob, just trying to learn.

 

[EagleFTE]

A lot of people blend their own cocktails with good results but I beleive the big name producers are probably pretty good at this themsleves. M1 auto 15W50 (silver cap) is a darn good oil with a additive package that exceeds what I see in any analysis on Harley oils. It just went up to $26 for the 5 Qt. jug at Walmart but still at $5.20 a Qt. it is a good deal and has been doing great in Evos for decades. There are many millions of miles logged on this stuff in Harleys. It is what I currently use in my 94. I would use a 40 wt. HDEO to get me home in that engine but not as a regular fill in the summer. All that said I see your desire to use up the 10 gallons. Maybe for fall/winter/spring short OCIs?? I don't know. Oil is cheap, engines are not. VIIs are said to be very vulnerable in applications that share engine/tranny/clutch due to shearing but that is not the case in your bike. You would be running the engine independent of the others. I do see some of the Buell guys using HDEO.

 

[PT1]

Originally Posted By: rksk
Thanks for the replies. Can you educate me on why a VII should not be used in this application. I am a noob, just trying to learn.


Heat in an air cooled engine. But you have a coole running EVO which should be ok with the 15w40 if you change the oil every 2500-3000 miles. Why not run a fill of the 15w40 and have a UOA done at 2000 miles and see how it comes back. OR just use 20w50 in the hot Summer months and the 15w40 the balance of the year?

 

[rksk]

Thanks guys, I appreciate the responses!

Based on the Motorcycle UOA's in BITOG, it appears that most 20w50 oils shear back to a 40 weight fairly quickly in Harleys, while the HDEO's seem to hold their viscosity very well in most motorcycle applications. There were only one or two Harley HDEO UOA's to base anything on, but the HDEO also seemed to do very well in the few Harleys that used it. I agree that 15w40 is too light for the summer temperatures, but I was hoping to be able to beef it up with a VII to overcome the light viscosity, while still reaping the benefits of shear stability and nice additive package of the HDEO.

This is not a long distance touring bike and I typically only ride it to work once a week (25 miles round trip, 20 of it is highway miles). Weather permitting, I ride year-round. It was 50 degrees during my ride to work this morning and the oil temp only reached 130-140 degrees in my 12 mile ride with the 20w50 HD-360 dino oil. I will probably run the 15w40 HDEO during the winter, and then switch to a 20w50 for the summer. I was hoping to use the HDEO + VII year-round, but based on the reponses I guess I will abandon that idea.

Thanks again for the replies.

 

[1WildPig]

Using the 15-40 would probably be just fine for year round use but I can understand your concern in very hot temps. I have used Rotella 15-40 for my "winter" oil in my '97 Evo and ran it til summer time with top ups done with the blue bottle STP in the spring with no problems..temps got up to about 85 before the miles said to change it out. As a matter of fact, I emailed STP and asked about it's use in a Harley, they said as long as the motor and clutch/tranny wasn't shared that it was fine. I say use just the 15-40 in the winter and change it out with the addition of a bottle of STP in the Summer months...I think it'll be just fine.

 

[PT1]

Sorry but I would never use STP in my Harley

 

[kballowe]

That 15W-40 works great for winter fill. It's a hard choice not to run it year-around when you have such a nice stash but if you are asking for opinions then mine is to run it for winter fill until the temperatures are above 60 or 70 degrees consistently.

 

[CATERHAM]

Lots of good advice here.
Do you have an oil temp' gauge?
If so your 40 wt oil is fine until the oil temp gets significantly above 212 F. And if and when it does simply avoid WOT....no worries.
Another option is to carry a very small quantity of VII improver (STP) with you and add it if the engine get very hot. BTW, it will only take about a 5% addition of STP to bump the viscosity to a 50 wt.

 

[coffee]

I think the 15w40 would be fine year around but it cannot hurt to switch if it makes you feel better.

 

[rksk]

Guys, thanks for all of the replies! I just changed my oil last weekend and went with Rotella 15w40 (no VII) for the winter. I will continue to monitor oil temperatures, and re-evaluate when the ambient temperatures get warmer (probably next spring). Then I will decide whether or not to add VII to the HDEO, or change back to 20w50. Thanks Again!

 

[wileyE]

Hate to say it, but 15w40 does have VII, not that it's such a bad thing.

 

[1WildPig]

Hey...just found this in another thread and took advantage of it...check out the sale on denniskirk.com for Bardahl 20w50 engine oil, Primary lube and Transmission lube...can't beat the prices and it's delivered to your door! I know you already got a good stash of the HDEO but you can always use it for a winter oil for your bike and for lawnmowers, etc.