i have read every report and every thread with respect to the use of the Shell Rotella 15W40 meant for diesel engines...in our MC's....there seems to be significant science that indicates it is not only safe to use...but could be beneficial in the long term... the question i have...is does anybody have any definitive scientific evidence that it may be harmful??? are there any lab reports or tests or conclusionary theories that show the use of Rotella to be deleterious??? thx...vs

 

It's a great oil. But unless you can get it in a 15w-50 or 20w-50, a case might be made that you are voiding your warranty as HD says to use the diesel oil only long enough to get it replaced with recommended oil. And if you are running a 15w-40 oil, diesel or not, you will most likely have a problem in a high heat situation. That top end viscosity, -40, will shear down to a low -30 fairly quickly, and that is way low for summer use in an air-cooled HD, especially a Twinkie motor. Youse guys in the more northern areas might get by with it, but y'all Southern Boys probably won't.

 

I just changed to Rotella because of the things I have read about it. I feel like it is a better quality oil than the cheap a$$ drag specialties brand oil that all of the few shops carry in my town. My Evo seems to run quiter with the Rotella. However, being in Alabama, I am leary about the HOT weather when it starts in about another few weeks. May change to Mobil 1 v-Twin 20w-50 synthetic, then. I like the Rotells for now, though.

 

Vagabond welcome to the forum!
I question why anybody would want to run diesal formulated oil in thier bike to begin with[sm=confused06.gif]. With the quality oils on the market specifically formulated for motorcycles, synthetic and otherwise. Readily available, competively priced. It just makes no sense to me. Maybe I'm missing something and if I am please tell me what that is.
Rotella is petro based, so regardless of any other benefits you might gain, you still have a carbon issue that you would not with a synthetic. Just curious what the benefit of diesal oil is.

Steve[sm=icon_rock.gif]

 

What he said...

 

thx for the welcome....i have spent quite a bit of time on the forum reading...i tend to lurk...until i have a question or comment that hasnt been made before.......i understand and respect opinion...and anectodal philosophy...but i was more interested in the science of the thing...i agree that intuitive thinking would tend to have one use a specific oil "supposedly" made for MC's....but so far...the only scientific evidence against rotella...is pococj (you arent from bc are you??)...[8D] with respect to lower viscocity of the 15W40 in higher temp areas...THAT is scientific based response based on empirical study...

i would have thought...that by this point....redline...or mobil..would have come out with a study completely advocating NON use of rotella for some specific or scientific reason...or is it just because they dont feel they have been impacted enough by the use of rotella???

again...preference and philosophical bent aside....the SCIENCE..tends to work in favour of rotella.....[>:] thx...vs

 

[sm=exactly.gif]What he said...But again, to each his own...I too understand what everyone here is saying and their individual pros and cons. However, I guess I can tear my scoot up with Rotella if I want. I guess that is what akes this country great [sm=biker2.gif][sm=americanasmiley.gif].

 

Nope, not from BC! East Texas, here. You won't find one of the oil companies advocating non-use of another company's product. Ain't worth the time and effort to begin with, and there would probably lawyers crawlin' all over some advertisements like that!

I don't use muttersickle specific oils. They just flat ain't worth the price given that I change oil at 2500 - 3000 miles. If you've read through here much, you'll know that I had several oils analyzed to back up my choice of using a less expensive car oil. But I don't run anything less than a 15w- or 20w-50, either. Partly 'cause it gets a wee bit on the warm side here, and partly 'cause I know that by oil change time, it'll have sheared to a mid-40w. I'm not willing to run something that will shear down to a 30w. I've run a 30w in my bike in an emergency. It didn't like it - lots of noise, and that translates to lots of wear!

The Shell Rotella-T synthetic 15w-40 is a great oil. It'll retain its viscosity well, but it is just too light for hot weather. No hot weather, no traffic jams, no parades? Probably OK. But in a Twinkie motor, I think it might just be a crap shoot. The oil temps in a Twinkie, even in cool season riding, are well above what I encounter in my Evo at the hottest time of the Texas summer.

I couldn't find any UOAs (Used Oil Analyses) on the Rotella in a Harley. On several other bikes that were water cooled, it held up well except that it sheared to a 30w. No big deal on those bikes as they were designed to run on a 40w. Harleys ain't.

Something to remember - In the near future the Heavy Duty Engine Oils (Diesel oils) will be reformulated to account for changes in the pollution laws affecting diesel engines, especially the reduction of sulfur. They may end up going the way of car oils and acquire additive packages that don't lend themselves to motorcycle use. I personally doubt they'll go that far, except that they may become unsuitable for use in a primary. But when they make the change, we may not know about it. After all, they aren't making the stuff for us, but for diesel jockeys.