Fuel mileage on the 650 relly varies depending on the type terrain your riding and how hard you are on the gas. I've got anywhere from 17 to 50mpg.
I don't use an oversize tank myself. In the XR650R group the guys have said the Clarke tank fits better than the IMS unit.

Here is a link to the group list, any question you have can be answered there.

I hope you enjoy your BRP, I know I like mine.

--
Andy Mullins

Livin up to Mom's low expectations



---------------------------------
Graves wrote:
> I recently picked up a 01 XR650 and haven't had a chance to ride it yet. I was wondering how far it would go on the stock tank (in miles)and how do those IMS 3.4 gallon (I think) tanks fit? Do they distort the seat? I have installed the power up kit and removed the air injection, other than that it is stock. Any information would be appreciated.