They also offer a 75W - 110 in their Severe Gear line if you want something a little lighter for better fuel economy in colder weather.

http://www.amsoil.com/storefront/svt.aspx

I live in NH and am planning on giving it a try next time I change my tranny oil.

 

I changed from Bel-Ray 75-90 to Amsoil 75-140 and found the same thing .. 3-4 mpg less .. It suprises me there is that much difference.

 

I've been running Amsoil 75w-140 since 1K miles. I'm at 7K now and like the difference. I've only started to keep track of gas mileage recently so I can't say if I lost any MPGs. I current get 42-44MPGs.

 

I used AMSOIL 75w140 in my 07 RK and liked it a lot but I decided to use Spectro 6 Speed in the new bike and I like it even better.

 

Interesting, I hadn't considered the effect on mileage. I'll be switching from 75-90 to 75-140 this weekend, so I'll see if there's a difference.

 

The only way you might see a difference is in real cold weather,but even then doubt it.Synthetics are the way to go when it comes to viscosity.

 

I accutually use 75-90 amsoil NOT 75-140

 

Spectro 6 Speed in my 09 RG. I like it.

 

I use the Amsoil Severe gear 75-110 in Phoenix. I dont believe anyone would require 75-140. I think you would be just wasting gas. My opinion only.

 

I'm using 75-140 here in Tucson.... I am at 30,000 miles and will change at 50,000 miles. I like it alot, now that MPG has been brought up as an issue, I'll change it out to 75-110 to see if there is a difference.