OK, here are my opinions about choosing oil. Its pretty long, better get a drink.

I feel that the big reasons that you get so many different opinions about oil is:

1. Weather conditions in different parts of the country. I'm in central Florida, so my riding season is all year round. In the winter I don't really get freezing temperatures, but in the summer I get 95 degrees and 95% humidity for a couple of months. City riding for me, with a lot of stop and go traffic, is brutal in the summer. In contrast, up in New Hampshire where my Dad is, the riding season is a lot shorter and temperatures get a lot lower in winter. Up there, even in the heat of the summer, the temps and humidity are not as bad as Florida.

2. Riding style and habits. My bike is my commuter vehicle, I ride 80 miles roundtrip 5 days a week plus whatever mileage I get in on the weekend.

3. Your goals. Do you have the extended service warranty? Do you plan to run the cheapest fluids and get Harley to fix any problems under the ESP? I put at least 15,000 miles on per year and plan to keep the bike for many, many years. I want to use fluids that will protect the engine, tranny, and primary in the conditions I ride.

So, where I live and ride I need oil that will handle the heat. Your riding conditions may be a lot different than mine, so different fluids may work better. Personally, I use Redline 20W50 in the engine, Redline Heavy Shockproof in the tranny, and Redline Primary case in the primary.

Here is why I use Redline. Back in 2008 I bought a new Heritage. Redline Heavy Shockproof was recommended to me by an indy that put in a Stage 1, cams, and dyno tune when the bike had about 500 miles on it. My original goal was just to quiet down the tranny and the first gear clunk.

I was already going to use the Redline Heavy Shockproof, so I also put Redline oil and primary case fluid in at the 1K service. Once it was in, I became curious about how well the Redline was holding up in the engine. To see how the oil was doing, I started getting oil analysis done regularly when I changed the oil. Blackstone labs will do it for about $20.

I changed the Redline oil in the Heritage regularly at 5,000 mile intervals, and every oil analysis came back showing less engine wear than expected. A quote from the oil lab at the 30,000 mile test really sums things up, "Just to review, universal averages for wear for the Twin Cam 96 CI are based on 3,700 miles on the oil. This oil was used longer, and yet wear metals still beat average pretty much across the board, showing a continuance of proper wear inside this engine. Recent wear trends have been low and flat, which is what you want. Try 7000 miles next run on the oil."

I wasn't interested in running the oil for longer periods, because I wanted low wear on the engine. Sure, I could try some of the other oil brands, and might get the same result, but then again I might not. I continue to use the Redline because it is proven to give me lower engine wear, which hopefully will let me put more miles on the bike before a rebuild is needed.

In January 2010 I traded the Heritage (had about 30,000 miles) in for a 2010 Limited. Wifey was never happy on the back of the Heritage, and as you know, if Wifey ain't happy, ain't nobody happy. At the 1K service on the Limited the dealer used Syn3 in all holes. The dealer threw in the 1K service when I bought the bike and I figured it was OK since the engine was still breaking in. When I did the 5K service I changed over to the Redline products. I have just now done the 10K service and will be sending an oil sample off for analysis.

My recommendation for picking an oil brand is this:
1. Pick an oil brand you like and run it for 3K to 5K miles
2. When you change the oil, send a sample to an oil lab for analysis. Blackstone labs can be found on the Web at http://www.blackstone-labs.com/
3. If the oil analysis shows either normal or excessive wear, change the oil brand to something else. I found that using Redline products resulted in lower than average wear, but YMMV

Remember, my riding conditions and style is different from yours, so my choices may not work well for you. However, if you test the oil you use, you can then decide if its doing what you want.

 

Yep Your Correct on the oil temp. 220-230 degrees. Too cold or to hot is not good.

 

I am using Amsoil products exclusively. 20W50 full synthetic in the engine and primary mainly because it comes highly recommended and from what I've read about the properties of Amsoil, it's as good as any and better than some.

I am switching from Amsoil 20W50 full synthetic in the transmission to Amsoil Severe Gear Lube 75W90 mainly to help make the transmission run a little quieter and shift smoother.

 

Okay, now you guys have created a couple of new questions for me.

First: Using 75w90 or a 75w140 sounds like a lot of difference. Is the 140 ok to use and why use it?

Second: Several posters have stated the higher weight rating and/or the Redline "Shock" oil for transmissions quiets the trans down and makes it shift better. It this really true? Shift better as in finding neutral or just overall shifting?

 

While there may be a correlation, I don't think there is a causation there (since we are all sharing opinions). Since the ATF never touches the tranny bearing (lubed by the oil in the transmission) how would that have an effect on the life of the tranny bearing? I could understand the correlation between the inner primary bearing and ATF, but it doesn't seem to exist.

The correlation I see with trans bearing failure is with guys that typically ride a lot and are prone to wearing things out faster. Coincidentally, some have discovered that they like ATF in the primary.... FWIW.

 

While the Redline oil may quiet the straight cut 5th gear to some degree and smooth out the shifting action, finding neutral, and clunk going from netural to first is really impacted more by primary chain tension and clutch adjustment. The only thing I had (and never considered it to be an issue) was the clunk going to first from neutral, especially when cold. Clutch plates stick together and gets the input shaft spinning. Dropping in to gear brings it to an abrupt halt (clunk). I'm one of the ATF in the primary guys and I never have that clunk. Cold start first thing in the morning, hot start after getting gas, or going back in to gear after a short idling period.... No clunk.

I'm not saying that ATF is the cure all. I've been very meticulous about adjusting my clutch and have found a good method and setting for my bike. What I do know is I had clunking with Redline in the trans and Formula+ in the primary. I have no clunking with Redline in the trans and ATF in the primary. YMMV.

 

Many people have used 20w50 syn in all 3 holes and no issues yet...It's a catch all lubricant for the shelf at HD. I like in the heat down hear to use gear oil in my tranny. I buY wALMART (LOOKS LIKE MOBILE 1) 75w140 syn oil. it's just a gear box like a care... in the primary i use HD primary fluid, have used 25w50, never tried ATF, motor i used, Amsoil 20w50, Mobil1 20w50, mobil1 15w50, HD syn...I have yet to see any difference to say really noticeable...Use one of these combination or the same in all 3 holes...go with your own preferences and change your fluids within the recommended specs and you will be fine.

 

I know 140 wt sounds much heavier than 90 wt, but for the application it's not. The transmission has gears that mesh together and rotate. There has to be enough clearance to move without binding. The pressure against the teeth can vary depending on the load. You have bearings and also needle Bearings. That's why they recommend a variable weight oil like 75/140. IMO the 75/140 adds more protection to the gear teeth. This is where the term shockproof comes in. I like Redlines V-twin Transmission oil. It has the extra weight for shockproof, but flows like a 90 wt. JMO

 

Very simple, use Amsoil 20W-50 in the engine and primary, use the Amsoil 75-110 in the tranny, done, this way you know what and how much to buy.

 

After buying 4 of the hotter running bikes. 08 UC, 09 EGC, 2010 RK, 2010 SG Trike, I'm becoming more of a believer in Redline Oil. I've been running Redlines V-twin Transmission oil in three of them with great results. I'm also running Redline primary oil in the two I still have. I just switched from Amsoil 20/50 to Mobil1 15/50 in my RK. The Amsoil I took out was black as soot after 4K of easy riding. I don't run my bike hard!