I use Silkolene 20/50 and when on the road Harley 20/50. My only experience with synthetic was with Amsoil, I gave it a good test too in an 87 FLH, I changed the dyno out, put in Amsoil, rode 100 miles, changed it again, filter also. Now with Amsoil in it I went for a day trip of about 400 miles. The weather was mild, low 70's. I found the bike made more top end noise and ran 20 degrees hotter. Changed back to Silkolene once I returned, quieter, temp down to normal. Personally I think synthetic(not Amsoil) is good for high mileage vehicles, with extra filtration, but as I change my oil very often I don't see the benefit to it. I tested the Amsoil as a favour and have never used other synthetics which I am sure are better but I will never put Amsoil in my bike again.

 

Grumpy the prices here are expensive too but I think if you can afford a synthetic it really is best for the bike in the long term.

I have also done some more surfin' the net and I have decided to go SYN3 as well. People have claimed it's not as good as Mobile 1 or Amsoil but I don't know why?

Harley recommends SYN3 as a alternative to the standard oil if you want to go synthetic, but according to them their standard oil is fine, so if cost is really a concern then I would stick to the standard Harley oil.

Here are some quotes I got from surfin':

QUOTE
What are the key benefits to using SYN3?

SYN3 is a multi-use oil, meaning that it can be used in the engine, primary chain case, and transmission. Because a person no longer has to juggle 2 or even 3 different fluids, the use of SYN3 is significanly more convenient than standard lubricants. SYN3 is also designed to offer better wear protection at high temperatures, improved deposit control for a cleaner running engine, reduced oil consumption, high temperature detergency, and overall performance.
UNQUOTE

QUOTE
Will I still need an oil cooler on my high performance engine, or does SYN3 cool faster?

One of the benefits of the Harley-Davidson selected Premium Quality 3 Synthetic Basestocks, Group IV PAO, and additive package is that they offer improved lubrication and cooling. SYN3 has been tested at temperatures up to 300° Fahrenheit, for extended periods of time with no significant breakdown. If someone is interested in running an oil cooler on their Harley-Davidson, a Genuine Motor Accessory oil cooler is recommended for optimal performance.
UNQUOTE

Visit this web site for more info on SYN3: Info about SYN3

 

After using SYN3 for 112,000 miles, I went to Amsoil, I can get the Amsoil for about half the price of the Harley oil. The SYN3 is $8.49 a quart[sm=forgetit.gif]

 

Syn3 is also a blend, not a true synthetic.

Funny how this topic and "debate" of best oil keeps popping it's head!

Mac

 

Seems I remember that Syn3 is a 10W40 weight when originally anounced, but I have resd recently that it is 10W50. Can anyone straighten me out on this. If iit is 10W40 that would make buying locally a lot easier as 10W50(especially in deisel rated ) is harder to find in the alternative oils around here???

 

I thought the Syn 3 was 20w-50.

And almost all oils advertised as synthetic are actually blends, even Mobil 1. They use regular oil as the carrier for their additive package. This carrier oil may make up between 9% - 20% of the total volume. I've seen some oil advertised as synthetic blended that had as little as 5 % synthetic.

There is a company that uses only pure synthetic base stock, and also adds the additive package with synthetic oil. But it is way too expensive for me to want to use in my old bike. Here's the addy if you want to wade through the hype. There is some very interesting info on the site. http://www.synlube.com/

The reason Syn 3 and many other synthetic oils aren't considered as good as Amsoil or Mobil 1 is that they are super-refined (my own term) regular dino oil base stock. Mobil 1 & Amsoil are built up, molecule by molecule, until the desired characteristics are achieved. Also, the wear characteristics, the viscosity retention, the ability to withstand high temps, and all other measurable factors of the M-1 and Amsoil are superior to Syn 3.

If you have to pay basically the same price for two oils, why would you buy the inferior product? And if you can find a superior product for 1/2 to 2/3 the price, why is there any question at all which product to use?

 

Did not really intend to buy synthetic; just trying to figure out if Harley was recommending a 10/40 or a 20/50 for all three holes. I will probably use Mystic 8 20/50 deisel rated oil in my Evo when I need to (it had the 1000 miles full dealer service just 700 miles before I got it so I have abot 1500 miles before I change the engine oil). I won't touch the other two cavities for another 7K or so (probably in the fall). I may try one of the major brand "blends" if I can find 20/50 for the engine though????? I will use a GL5 gear oil for the tranny when the time comes. The primary will get dino 20/50 of some kind.

 

Well Mac the saga continues I guess:

QUOTE
Is SYN3 a full-synthetic or a semi-synthetic oil?

SYN3 is a full synthetic lubricant. It is the general practice in the oil industry that a true synthetic is formulated with Group IV PAO basestocks and is a true synthetic.
UNQUOTE

The people at Rocky Mountain HD seem to think SYN3 is a full synthetic.

I still believe Mobile1 is best but I am going to use SYN3 for now. I suspect I will switch later but as long as I am using a synthetic I am happy.

 

Skip

You are probably correct but newbies like me want to play it safe, or at least think we are playing it safe, by sticking to Harley recommended oil. So, umm, the only logic that applies for me for now is does HD recommend it, right or wrong, I sort of think we are splitting hairs when comparing syn's except for the price variations which I will tolerate for now.