What do you prefer and why?
Any particular brand?

 

Lol. Here we go.

 

My 2013 SG is under warranty so I put exactly what Harley calls out in the manual........I will probably continue doing that after the warranty.

 

This has been beat around a lot. I personally prefer synthetic because I sometimes get stuck in traffic on hot days and oil temp gets higher than I would prefer. I do still use HD Formula+ in the primary. I still change fluids every 5k miles even though I know I could probably go longer particularly on the trans. I usually use Mobil 1 because its more readily available in my area. 20w50 or 15w50 in the crankcase and gear lube in the trans.

 

synthetic better handles high heat
( oil will break down under very high heat, conventional breaks down at a lower temp than syn)

remember that the twin cam is the first Harley Motor to spray oil directly at the pistons, pistons are hot

the quality of the castings, machining and material seals the synthetic in the cases.


the job of the oil is to lubricate the moving parts and provide a film for the bearing surfaces the ride on- and also to carry heat away from the hottest parts of the motor where the heat can be dissipated.



I run conventional oil in my old bikes, syn in my twin cam.
I use the stuff in the manual


mike

 

God I love winter on HDF

 

But that allows you flexibility. HD can't force you to use HD oil and other fluids. They just need to meet the api specs for the application.

Sent from my Galaxy Nexus

 

Mobil 1 synthetic. It lowers head temps 23.6%, increases hp by 9.17% and torque at least 11.26%.

 

Put Syn in your V-Twin
go for a spin and grin
when you change it do syn again
every time you pour it in you win
for the big twin loves syn
no matter what climate you are in
use the syn and win.

 

really?

s e a r c h