Road Glide banner

1 - 11 of 11 Posts

·
Registered
Joined
·
2 Posts
Discussion Starter #1
My new 2011 HD Trike states in 103 operating and maintenance manual to use full synthetic diesel oil if HD oil is not available. This would be very handy since I have a diesel truck using full synthetic for years. Why, is hd oil diesel oil?
 

·
Registered
Joined
·
1,477 Posts
Diesel is made to withstand the higher temperatures. The higher temperatures come from the cooling jets that squirt oil directly onto the bottom the pistons to help extract the heat soak from the higher combustion chambers. The twin cam engine uses these same cooling jets to keep the piston temps down as well. The lean burn is to comply with the epa, a byproduct is the heat from running so lean. This is probably the single biggest reason twin cams oil temps are so much higher then evo's. Everyone freaks and frets over the oil temps but running 230 plus degrees is perfectly normal. IIRC the oil temps and both diesels and twin cams can reach 320 plus degrees without degrading the oil.
 

·
Registered
Joined
·
855 Posts
Good information, thank you for sharing!
 

·
Registered
Joined
·
29 Posts
Actually there's a few additional reasons as well. I did a buttload of research into what oil I could run in my Night Rod and wound up with a good deal of info. One of the main reasons that diesel engine oil is advised is that it doesn't have the anti-friction additives present in passenger car oils. Anti-friction additives wreak havoc with wet clutches, often destroying them before the oil can be changed out.
Also with a common sump like the V-Rod line your engine oil is also shared by the transmission. The shearing forces forced on the oil as it attempts to lubricate the gears would break down it's viscosity if it were regular passenger car oil, diesel oils have more resistance to viscosity breakdown.

But really, it's too easy to find the synthetic V-Twin motorcycle oils made by Lucas, Royal Purple, Mobil 1, and the MOST inexpensive, Valvoline. I ran Valvoline in my Night Rod Special and the clutch tightened up nicely. And it was $7.59 or so per quart (FULL synthetic). The MoCo Syn-3 is approaching $13.00 a quart, that's ridiculous. I won't pay it.
 

·
Registered
Joined
·
955 Posts
I use Amsoil and both of my bikes shift and run smooth as silk.
 

·
Registered
Joined
·
3,042 Posts
I think you'll be hard pressed to find a synthetic 15w-40 or 20w-50 oil that's not diesel certified. I've been running Mobil 15-50 car oil in my bikes for the last 10+ years, no issues.
 

·
Registered
Joined
·
1,270 Posts
My new 2011 HD Trike states in 103 operating and maintenance manual to use full synthetic diesel oil if HD oil is not available. This would be very handy since I have a diesel truck using full synthetic for years. Why, is hd oil diesel oil?
The Rotella diesel oil is JASO-MA certified which means it meets the spec for H-D use.
 
1 - 11 of 11 Posts
Top