Originally Posted By: Jimkobb
I forgot to post that I was wondering about this for use in a 2013 Road Star by Yamaha. I didn`t know if they were interchangeable and if so did the 75w-140 have any added benefits . Currently I`m using Redline 75w-90 .
The only reason to go to a 75W-140 instead of the recommended 75W-90 is if the final drive is excessively noisy, or very rough when shifting. If you are not experiencing either of those, there is no reason to move to a 75W-140.