I purchased 5 quarts of the Mobil VTwin 20/50 and one of the 75/90 tranny and took it to the dealer for my 1000 service. I asked them to put this into the bike. The service manager asked...do you anybody who is using this stuff?" I said, yes, the rest of the friggin free world.
It's your bike, you dictate what goes in it! Don't take crap from anyone, especially the dealer.

 

I don't think synthetics run cooler enough to feel the difference, they just hold up better under the severe heat of the air cooled engine, and therefore lubricate better and last longer.

 

I found no difference in my temp per the screw in oil temp guage. However, synthetics do withstand heat before breaking down vs dino.

 

Syn 3 all three holes with over 100,000 in 02 ultra,and runs great.

 

i dumped syn3 after 1500 miles the motor sounded like it was going to rattle apart put in mobl 1 quiet & purs like a kitten

 

Asking a question about which synthetic oil to use is like asking which color is better black or red. Each person has theeir preference. Syn3 by Harley Davidson is a good oil as is all the others. Synthetic oils do not break down under heat as soon as normal carbon based oils do. I have been running Syn3 in bikes ever since they came out and have never experienced a failure. If their were massive failures out there Harley would pull the oil off the shelf. Not saying it is the best oil out there but it is far from the worst in my opinion.

 

I was having problems on my wifes bike stalling in hot hot temps, I tried Syn3 from hd and only noticed a slight difference, I found that once I changed to AMSOIL the over heating problems with her bike disapeared.

 

My engine runs a lot cooler since I started using Lucas synthetic 20W50.
I also use Lucas oil in the tranny and
primary oil in the chain and clutch. (that's what it's made for)
I don't believe in one oil for different purposes.

Ride Safe
Greetz Peter

 

Why not use Mazola oil then , it's good enough

It'll get by , but most want more than just "good enough" after spending the $$$ on these bikes. Why not use a quality oil that is a FULL synthetic instead of an imitator that costs the same or more than a full synthetic?

 

If you check into this, HD is no longer advising the use of syn 3 In the trans. It has been replaced by Formula+ now. That in itself should tell you something about the oil in the trans.

The failures that occur from the use of this oil are not broadcast to the public for obvious reasons just as the "design faults" of later day bikes are not advertised either, rather they are smoothed over with an upgrade of some sort..

If you know anyone that works for a dealership, you can see what the syn 3 is doing in the transmissions for yourself and not take anybodies word for it.. The use of syn 3 is pushed by the dealers more than HD themselves as it is easier to stock one size fits all when it comes to oil.