42904 V-Twin Primary Case Oil, For use with UTVs, ATVs and Sportbikes - 1 Quart (4 Pack)

So far so good

Best synthetic oil for your V-Twin if your engine is modified (big bore build, or camshaft, etc.). High performance engines put off more heat and this oil is hands down the best I've used thus far to aid with the high heat matter. I use this oil in the summer/high heat seasons and then use AMSOIL for winter storage/minimal riding, just the engine oil. I keep my primary and transmission filled with Red Line all year round. For context, I ride a 2020 Road Glide Limited and live in Northern Virgina by Shenandoah.

excellent in all regards

Works great

As expected

Probably the best primary fluid around. Clutch engages smoothly, and really quiets the mechanical noise. A note of caution when ordering. As others have noted, ckeck the amount of oil your specific bike needs. Several reviewers have models requiring 38 ounces. I’ve attaced a pic from my owners manual on a 2024 Streetglide with a Gen 2 M8. 34 ounces if filling from dry, 30 ounces if a wet refill. I assume the Gen 1 M8’s are the same. Can’t remember what it was on a Twin Cam.

says its for sae 75/80w but its 10w/30

Red Line bottom line the best for my bikes and high performance vehicles. Removed Willie g derby cover and back to stock while servicing my primary fluid on my street glide. Also used in my 2022 fat boy.

For 2011 FLHRC. Has made neutral easier to find.

Performed an oil change prior to a 4600 km road trip. This bike was new to me and therefore wanted my first trip with new oil. Went through some extreme temperatures on the trip and no issues to report. Good products.

Best oil for Harley

Wow!!! Had a bit of noise before but it is practically gone now. Shifting between gears is also smoother!!

As advertised.