Ok, so I've decided to switch to synthetic oil, do I use the same viscosity as petroleum based oils?

I have a 2000 Sportster, based on the owner's manual it looks like cooler fall and spring riding I need 10W-40 and 20W-50 for summer, does this seem right?


What weight gear oil should I be using?Ok, so I've decided to switch to synthetic oil, do I use the same viscosity as petroleum based oils?
You want to stick with 20/50 (MAKE SURE IT IS FOR V-TWIN MOTORCYCLES....NOT AUTOMOTIVE OIL!!!!)......you can also run the same oil the primary/trans.





Here is an answer to a similar question...although it is in reefernce to a Big Twin.....the concept is the same though.....





As much I love HD....I hate to say it, but HD doesn't know SH*T about synthetic oil. For decades, they said not to run synthetic in their engines.....because of popular demand by the public, HD finally came out with their SYN3 synthetic oil several years ago, but it is honestly not worth a crap. THE BEST 3 SYNTHETICS FOR A HARLEY ARE


#1-AMSOIL, #2-LUCAS, #3-MOBIL1(which is recommended by S%26amp;S). I have been working on HD's and building performance engines, drag racing and dyno tuning for 20 years and have been running Amsoil for years, but have recently switched over to Lucas because it is just as good, but a little cheaper. AND THEY DO NOT AND WILL NOT VOID YOUR WARRANTY


FIRST OFF.........DO NOT RUN HD SYN3.....IT'S JUNK.........I AM A CERTIFIED HD TECH, AND I WILL TELL YOU FIRST HAND....HD DOESN'T KNOW JACK ABOUT OILS!!!!!!!!!


For deacdes, HD said to never run synthetic in their engines, their reason....it will cause the bearings to ';skate';.........but ask anyone on the drag strip running a top fuel 800+ HP engine what they run.......FULL SYNTHETIC.......their bearings don't skate!!!


By popular demand of the public, HD finally released their SYN3 back in the early 2000's......manufactured by Sunoco. SO........


Second......why would you WANT to go longer between oil changes?......esprcially on an Ultra, the baggers are subjected to to more engine strain than the other models due to their weight, plus they run hotter from not as much aie flow, that's why they have a larger oil tank to aid in cooling. FRESH OIL IS CHEAP INSURANCE AGAINST ENGINE FAILURE. Standard oil you should change every 2500 miles. You CAN go about 3500 on synthetic, but why? Scheduled PREVENTATIVE MAINTENANCE set by the factory are based every 2500 miles, IT IS BEST TO CHANGE YOUR OIL EVERY 2500 MILES....SYN or STD. Keeping up on the maintenace, prevents major breakdowns. It's btter to spend $400 or so a couple times a year than spend a few thousand to repair something that was caused by lack of maintenance.


As the other guys have said, synthetic does make your engine run cooler and lubricates much better than standard oil.


The best synthetic to run is 1) AMSOIL or LUCAS 2) Mobil 1


It is ok to run the same synthetic in the primary as you do the engine.......but NEVER use that same oil in the trans. HD says you can, but it makes the trans hard to shift and noisy......run minimum 75/90 gear oil......best if its 85/140......the absolute hands down best trans oil on the market is RED LINE full synthetic Shockproof 85/140...it will make your trans runs smoother, quiter and shift easier.Ok, so I've decided to switch to synthetic oil, do I use the same viscosity as petroleum based oils?
this is the oil you need good luck http://www.caracheosyntheticoil.com/inde鈥?/a>





10W-40 Advanced Synthetic Motorcycle Oil Product Code: MCFQT-EA








Advanced multi-functional formula for both domestic and foreign motorcycles. Recommended for high-performance liquid or air-cooled 4-stroke engines and transmissions and both 4- and 2-stroke motorcycles. Wet-clutch compatible. Not recommended where an API GL-4 or GL-5 gear oil is required.


Click here for more information














20W-50 Advanced Synthetic Motorcycle Oil Product Code: MCVQT-EA








Advanced multi-functional formula for both domestic and foreign motorcycles. Excellent in air-cooled motorcycle engines due to high heat resistance. Can be used in engines, transmissions and the primary chaincase. Not recommended where an API GL-4 or GL-5 gear oil is required.


Click here for more information





http://www.caracheosyntheticoil.com/inde鈥?/a>
General rule of thumb is NEVER use thicker viscosity than what's recommended. You can always go thinner on the cold side though, like a 5w40 or 10w50.
Use the same grade for mineral, semi-synthetic and synthetic as the handbook says.
well i use full synthetic and i use 0w 30 ts looks like water pretty much but i get about 8000 miles out of an oil change check out amzoil its a really good oil