Some say it makes a difference where you live. Climate wise that is.
I think it is personal preference.

 

In all seriousness...any synth will ALWAYS make your engine run cooler, protect it better, and last for longer intervals than conventional. There is absolutely no reason to be cheap and run conventional after the first 1000. Anecdotal stories of high mileage engines running on conventional doesn't make any of this untrue.

 

I read and saved the Amsoil "White Paper" oil test they did some years ago. Mobil 1 V-Twin did as good or better in most tests as their own brand. I've been happy using it since.

 

...Another reason; on our road trip of 2010, we ended up one afternoon riding up South Mountain in Phoenix on a triple-digit day. Seldom out of 2nd gear on the climb up, when we reached the top, I checked the oil temp in the Road King with the digital thermo dipstick...279-F. ....glad I had M1-VT in it.

 

I vote synthetic. Made with special properties to promote a cooler oil temp.

 

Look at it this way...

You spend good money on a new bike and then you will probably spend thousands on mods during the course of ownership. Don't cheap out an save a few bucks running dino oil when there is a proven alternative available. It only takes 3 quarts or less, per change. Is your new bike not worth that?

These bikes run hot as the Kate Upton catdaddy video!!!!

Also, if you want to save money running a Full Synthetic, try Mobil 1 V-Twin 20w-50. Its readily available at any Auto Zone or Advanced Auto and usually decently priced. As a matter of fact, I just picked up 3 quarts for $8.99 each at Advanced Auto. If you do your own labor, you will be saving lots of money, regardless of whatever oil you choose to run.

 

I am from the Niagara Region close to the boarder anyone know where I can get Amsoil? Its funny but its advertised all over but try and find some? I will even try Mobil 1 Vtwin. I have searched many places in the US but seems to be anything but.
Thanks

 

Synthetic in both Street Bob and Automobile. Now that the Dino vs Syn.thread is out of the way. (Even though I was expecting someone to claim that he's seen bearing slippage caused by synthetic oil :>} ) Who's going to start the "Which brand so you recommend...Amsoil, Redline, Mobile or Harley." Tongue firmly in cheek.

 

My F-150 calls for synthetic blend and that is what I use...Ford synthetic blend and OEM oil filters. I am new to Harleys so when I bought a used SG from a local dealer, I naturally asked what oil I should use in it...I was told that all used bikes are serviced with HD filters and HD synthetic oil before they are sold. I was also told that the engine, tranny, and primary are serviced with the same synthetic oil which makes it convenient.

 

I went royal purple synth because I live in AZ where it gets stupid hot in the summer. Synth is supposed to run cooler so I went that route.