syn oil
Ultimate HDF Member
Joined: Jun 2007
Posts: 9,193
Likes: 494
From: Richmond, VA
You'll never get any ten people to agree about syn vs. dino oils. I run a semi synthetic. That was if it ever comes to light which oil is actually the correct or "best" oil to run in your bike, I will have been running it all along.
Cruiser
Joined: Feb 2009
Posts: 107
Likes: 0
From: appomattox,Va
syn or dino
I use Mobil 1 in all 3 bikes(`97 RK,`02ElecGlide and `02 Honda VTX 1800) The engines are noiseyer than with the dino but you have that start up protection you dont get with dino.I have no leaks but i warm up first.I change all fluids @ 3,000mi.Engine,tranny and primary so i could use dino with no ill efect.i have been using syn oil in all my vehicles for so manny years with good luck so why change. Also remember all oil is so much better now than it was a few years ago so tou are pretty much safe whatever yuo use.---Skip C
Stellar HDF Member
Joined: May 2009
Posts: 2,856
Likes: 127
From: Middle of Kansas
I am like said above. My 99 EVO had Castrol GTX 20-50 in it when I got it. I switched to Mobil 1 V Twin 20-50, and it started to weep a little from both cylinders. I switched back to Castrol and it quit. That was 11,000 miles ago. Still no leaks, and I always warmed it up with both. They are both good olls, just my old EVO likes Castrol better.
Intermediate
Joined: May 2009
Posts: 33
Likes: 0
Oil is not oil
My 1996 FXSTC had 7000 miles when I got her. I have been running Amsoil 20W50 in the engine ever since. The bike now has about 22k on it and runs like silk.
The ONLY issue that I have seen is that if I go for a two week period without starting the bike when the weather is cool, it will weep a minor drip out of the rear base gasket for about 30 seconds upon first starting it. That is IT. As soon as the engine gets warm, the drip stops. Doesn't do it during warm weather or with regular riding. I have also never had to add oil between changes.
Of course, I am religious about changing fluids and change the oil every 2000 to 3000 miles. Does it cost a little more? Yes but I feel confident that the bike will run for a very long time. Also use Amsoil 20W50 in the primary and 75W90 in the trans. No probs!
I know everyone doesn't agree on oil... but they should. Hahaa!
The ONLY issue that I have seen is that if I go for a two week period without starting the bike when the weather is cool, it will weep a minor drip out of the rear base gasket for about 30 seconds upon first starting it. That is IT. As soon as the engine gets warm, the drip stops. Doesn't do it during warm weather or with regular riding. I have also never had to add oil between changes.
Of course, I am religious about changing fluids and change the oil every 2000 to 3000 miles. Does it cost a little more? Yes but I feel confident that the bike will run for a very long time. Also use Amsoil 20W50 in the primary and 75W90 in the trans. No probs!
I know everyone doesn't agree on oil... but they should. Hahaa!
Road Captain
Joined: Mar 2008
Posts: 601
Likes: 6
From: Aruba
Hehe. In the boat forums, you get banned for starting "another oil thread".
There are hard facts to back up that metal parts wear less with synthetic oil than dino and synthetic oil doesn't break down nearly as fast as dino oil especially in high heat situations like an air cooled motorcycle engine. All the rest is just opinion and personal preference. There's also all the ridiculous myths about synthetics such as roller bearings will slide instead of rolling causing failure that have been totally disproved.
More importantly, if you change your oil regularly you won't see a whole lot of difference no matter what oil you run. Dirty, broken down oil is what causes the most wear and tear, not my super duper oil is better than your run of the mill oil.
That said, I always run Amsoil if I can get it and Mobile 1 V-Twin if I can't. That's based on independent testing of the three ball wear test.
There are hard facts to back up that metal parts wear less with synthetic oil than dino and synthetic oil doesn't break down nearly as fast as dino oil especially in high heat situations like an air cooled motorcycle engine. All the rest is just opinion and personal preference. There's also all the ridiculous myths about synthetics such as roller bearings will slide instead of rolling causing failure that have been totally disproved.
More importantly, if you change your oil regularly you won't see a whole lot of difference no matter what oil you run. Dirty, broken down oil is what causes the most wear and tear, not my super duper oil is better than your run of the mill oil.
That said, I always run Amsoil if I can get it and Mobile 1 V-Twin if I can't. That's based on independent testing of the three ball wear test.
Seasoned HDF Member
Joined: Mar 2010
Posts: 38,293
Likes: 6,322
From: Honah Lee
Crudely, Syn is just more refined regular oil. Its better. How much, who knows? It's onley measurable in a bunch of words. Will not cause leaks. No way to prove it will make your engine last any longer, does not reduce heat any better than regular oil, nor does it make it any quieter and it will not make the Harley go any faster. Will take a few more greenbacks out of you pocket. My 10 cents worth but who's counting.
Last edited by Jackie Paper; May 24, 2011 at 12:10 PM.
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Road Captain
Joined: Mar 2008
Posts: 601
Likes: 6
From: Aruba
Crudely, Syn is just more refined regular oil. Its better. How much, who knows? It's onley measurable in a bunch of words. Will not cause leaks. No way to prove it will make your engine last any longer, does not reduce heat any better than regular oil, nor does it make it any quieter and it will not make the Harley go any faster. Will take a few more greenbacks out of you pocket. My 10 cents worth but who's counting.
More money? Amsoil can be purchased online for $30 per gallon. Last I looked in the States, HD dino oil was $10 per quart. HD Syn is quite a bit more. There's not too many oils that have the additives "required" (those groups of letters on the bottom of the label) for V-Twin air-cooled motorcycles that are less expensive unless you're talking about diesel oil which has more detergents than we would like.
Running cooler, no way to prove it, but my girlfriend's 2004 Sportster with a thermometer oil dipstick reads 15 degrees cooler day in and day out with Mobile one in it. My 2002 Heritage ran about 10 degrees cooler also. (Both of those engines normally run very hot.) I don't notice a difference with my 93 Evo but Evo's don't run nearly as hot and mine came with an oil cooler installed. I have a hard time getting the oil tank up to 150 degrees on a 90 degree day. (Top speed limit down here is 50mph.)
The general gist of your post I do agree with, however. And that's why oil threads are banned in the boat forums. *climbs down off soapbox.
Last edited by 95yj; May 24, 2011 at 12:59 PM.
Intermediate
Joined: Jun 2010
Posts: 41
Likes: 0
From: California / Sierra
I have a 99 FLSTC. I bought it with 11000 miles on it. Previous owned stated he had always used syn oil in it. I have continued to do so. Amsoil in the motor, Redline in the tranny and primary case. I have had no leaks. Bike runs cool and shifts smoothly/quietly.
Does syn oil cause leaks or just find it's way through gaskets in need of replacement that dino oil doesn't find it's way through? I think the latter.
My 2 cents.
Does syn oil cause leaks or just find it's way through gaskets in need of replacement that dino oil doesn't find it's way through? I think the latter.
My 2 cents.