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Synthetic fluids for Harley- Whatcha usin' & why?

10838 Views 9 Replies 8 Participants Last post by  RG06
Hi all!

Just curious as to what is being used in the crankcase, primary, and transmission by the Harley crowd, and why. Tried looking on the net for info; mostly confusing manufacturer hype. Figured ask the people that ride Harley's. How about the oil filter? Looking for a compatible, readily available filter in the 10 micron range.
Any help would be greatly appreciated.
Thanks

Yngwie
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I've used synthetic oil (Mobil 1 V-Twin lately, Mobil 1 previously) in my HD engine for quite some time, but the only reason I do is because it's so hot here in South Florida. The synthetic drops the engine temp from almost 250 to below 200 in the summer. If it weren't for that, I'd run a quality mineral oil. I change the oil in my HD about every 1.5k miles; it gets really dirty really fast, so the synthetic gets expensive. For filters, I use HD. Trans and primary case, regular (non-synthetic) HD gear and primary case lubes.

BTW: I haven't heard anything good about HD's Syn3 from anybody whose opinion I respect. The best I've heard about it is that it's ok for the primary. None of the mechanics I know at the local dealerships run it in their bikes.
I didn't know...

I've used synthetic oil (Mobil 1 V-Twin lately, Mobil 1 previously) in my HD engine for quite some time, but the only reason I do is because it's so hot here in South Florida. The synthetic drops the engine temp from almost 250 to below 200 in the summer. If it weren't for that, I'd run a quality mineral oil. I change the oil in my HD about every 1.5k miles; it gets really dirty really fast, so the synthetic gets expensive. For filters, I use HD. Trans and primary case, regular (non-synthetic) HD gear and primary case lubes.

BTW: I haven't heard anything good about HD's Syn3 from anybody whose opinion I respect. The best I've heard about it is that it's ok for the primary. None of the mechanics I know at the local dealerships run it in their bikes.
...that you had to change oil in a Shovelhead. The burn/leak rate on mine meant that you went through 3 quarts every 1500 miles. Of course I had to change the filter frequently because of all the metal shavings and chunks that would clog it up regularly.
I use Mobil 1 15-50 car oil in the engine and change it and the stock oil filter every 5k, for the trans and primary I use Mobil 1 75/90 synthetic gear lube and change every 10k. In my Suzuki I use Shell Rotella T 5w40 full syn. and change every 5 k and the gas-guzzeling SUV gets Mobil 1 5w30 extended service full syn. and gets changed every 15k. I'd use Rotella T in that too if they made a full syn. 5w30 weight.

The weather here is mostly cooler with only a month or two of 80's and 90's. Oil and tires tend to last longer than hotter parts of the country, so IMO short oil changes are a waste of money.
Every 15k for an oil change on an SUV? Isn't that a bit extreme? When I asked my mechanic about taking longer intervals to change oil using synthetic instead of non-synthetic, he told me that oil should be changed at normal intervals because it gets dirty. I use synthetic for easier starting in the winter (in my cars) and in my motorcycles because they turn at higher rpm's. But I never go longer than 3-5k intervals.
...that you had to change oil in a Shovelhead. The burn/leak rate on mine meant that you went through 3 quarts every 1500 miles. Of course I had to change the filter frequently because of all the metal shavings and chunks that would clog it up regularly.
The burn rate means I go through 3 sets of sparking plugs every 1500 miles. The HD-1 drop in filter only catches items the size of AirHawk's kidney stones or larger...
Every 15k for an oil change on an SUV? Isn't that a bit extreme? .
Not really, the recommended oil change interval is 7.5K with dino oil, synthetic oil doesn't break down so it's really the oil filter that determines how long to go. Mobil states that their extended service oil is good for 15k and they warranty against any oil related failures using their product so that's how long I go. The oil does get "dirty" but that's what the filters for, I use either the high end Purolater or stock Ford FL820S

Long haul trucks go upwards of 150k on their oil in hi compression-hi temp turbo diesels, true, they have multiple filters and they do oil analysis to determine the state of the oil but I figure 15 k in a modern standard gas engine is fine.

The 3k oil change interval is from the stone age of less complex oil matrix's and less precise manufacturing tolerances, leaded fuel and less efficient combustion. I think it's a waste of money and rescources to follow that in a modern gas engine.

It is of course entirely up to you how often you change your oil and I'm not saying anyone should do as I do, however reading up on oil and oil change intervals convinced me short oil changes in a modern engine was unneccessary
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I'm with Sarnali here - If I changed oil every 3k on my FZ6, it'd be an oilchange every month or so.

Mobil 1 15w50 for bikes, 10w30 for the pickup, change it at 12-15,000-mile intervals. Zero oil-related problems with anything I've run it in.
Is this the first "Oil Thread" of the MO v2.0 era?


One of my more anal-retentive buddies runs the Harley synthetic in all three "bags", engine, primary and transmission (I think) on his dresser. He buys it by the box online to save money. He has never had any oil-related problems. IIRC, he changes oil at 5K.

He runs synthetic in his Duramax's (C5500 Kodiak, 2500HD), which are both on an Oil Management (analysis) program. He changes oil once a blue moon on them. Which is good, since they take almost four gallons each.
Currently running AMSOIL 20W50 in the Motor, AMSOIL 75W140 Gear oil for the Tranny and H-D formula + for primary....seems to be a good combo. I have used Redline ShockProof Heavy in the Tranny it it worked very well too..
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