Oil is oil, provided it meets the minimum specs that Harley recommends. My preference is Mobil 1 V-Twin because synthetics can take more heat before breakdown. It's readily availabe at any Walmart and chain auto parts stores, too.

 

It would be interesting to know how many of the naysayers started an oil thread when they were new to the board.

 

I use WD-40, that way if I accidentally were to add water, it would be displaced.

Oh, and to the guy who's been using Syn-3 for 15 years, that's a neat trick since it was introduced in about 2003.

 

Isn't HD's minimum recommendation that you use nothing but HD branded oil, period ? Honestly not trying to add to the sarcasm here but I'm curious as hell to know just whats actually in HD's oils. So far my best guess is that "proprietary" is synonymous with "Group III" and thats what Syn-3 most likely uses as its base. My reasoning, simply put, is that every motor oil Co that uses expensive PAO's and/or diesters as a base, tends to literally brag about it. You don't hear many Co's brag about controversial "Group III" (synthetic ??) oil but we all know its out there.

Anyhow, as others have somewhat blithely pointed out, its doubtless no biggie what oil you use as long as you occasionally change it, but my aging mind struggles against the logic of the ; "just STFU and buy it" rationale as a reason why I ought to be spending my $ on things.

To the OP, I'll answer that, FWIW, I'm a fan of true, (Group IV & V), synthetic oil brands but not of the extended change intervals they may recommend. I use Redline and change it according to my HD owners manual. To those who may concern themselves with the efficacy with which I spend my $ on oil, please rest easy. I'm OK .

 

Ok, sorry 12 years. Geez, I'm lucky if I can remember how old I am... I know i started using it in my 2002 Fat Boy as soon as it came out.

 

[QUOTE=bradja;13584651 My dealership accidentally put Dino back in and I could honestly tell.[/QUOTE]

I bet they accidentally charged you for syn too.

 

I dont care what oil one uses, we all chose what we feel good about because whatever the reason you use it, is most likely the wrong reason and wont make one bit of difference as far as how your engine wears, unless of course you choose an oil that truly shows low wear numbers in your bike.

So it doesnt matter if you choose synthetic or conventional because certain products from BOTH show superior wear numbers compared to the others, yes, some conventional oil out perform MANY synthetics.
However the stand out for best wear is Amsoil and that is a syn. Mobile 1 another syn is close ... and Harleys own conventional 360 is close.

Never mind the great products from Valvoline, syn or conventional, some of them turn in great numbers as well.

One thing for sure, it is true a syn will hold up better and not break down as fast if your one to change at or after the recommended mileage. But it doesnt mean that oil is better at preventing wear and isnt it wear we care about?

If your like me and change a couple times a year and on or before 3200 a miles or so take your pick and pick an oil to prevent wear. Amsoil is a standout, Mobile 1, Conventional Harley 360, any of the Valvoline VR1 Syn or conv and even Valvoline motorcycle oils are great products.

Anyway, my morning rant, bottom line is quality oil is quality oil, synthetic OR conventional and only testing can prove it better at wear then the other NOT the marketing information on the container or the magazine ads etc.

Even when better wear is proven, in some cases, between the well known brands your splitting hairs. But my biggest point is a few good conventionals outperform the "boutique" expensive synthetic oils some choose when it comes to WEAR.

 

I have used Amsoil 20w50 for years... but due to availability of sourcing, and cost, I have switched to Mobil1.

I have seen numerous UOA's on both Amsoil 20w50 Motorcycle and Mobil1 20w50Vtwin out of the same Harley, and the numbers suggest Mobil1 is actually better.... not by a lot, but better.

Even after I saw those UOA's, I continued with Amsoil for 4 or 5 years...

Couple that with the fact I can get Mobil1 less expensive, and it is readily available, that's where I'm at now.

And I'm not bashing Amsoil, I absolutely swore by the stuff for a lot of years.

We had a national distributor that sponsored another forum I frequent, and ordering from him was simple. He knew me by name, I called, told him what I wanted, and it showed up on the brown truck a couple days later. I saw him at Daytona Bike Week in '11 and shook his hand, told him my name, and he recited my address from memory... then bought my a few beers. For his own reasons, he is no longer sponsoring over there, and the new guy directed me to a website, sign up for this, pay this fee, and put in my dealer number.... The old guy had my CC on file, and signed me up for whatever he needed to get me the best deal. I usually ended up paying under 8 bucks a quart.

Now it's just easier to go to wallyworld and pay 9 or 10 for Mobil1...


Sorry... didn't mean to ramble

 

Shear resistance or, "not breaking down as fast", is a key element in Synthetic's superiority over conventional oil as are its characteristics when temps are high. I haven't seen one of those impressive looking "wear" demonstrations conducted using old oil or oil that is extremely hot.

I'm no Chemical Engineer but I've read a great deal on what they have to say regarding synthetic oils vs conventionals. "Day one" "cool" oils may all perform the same regardless of their base stocks, as you say, but the performance spread will widen when time and temperature take their toll.

 

Rushmore bikes have the SE compensator, it works well with HD Formula+ oil.