Top speed on mine has only been around 54 and gas of course varies with the terrain I'm riding. I recently purchased a flat gas pack you don't even know it's there and you have almost another fill up with you when you need it.

 

[img]i/expressions/face-icon-small-happy.gif[/img] I have 650 hard miles of rocky mtn trails on my Rubicon and I average about 75 to 80 miles on a tank of gas(mountain trails and some open roads). And as far as speed Iv'e been able to get it to 54mph on a flat road at 9800' elevation. Great running machine and who cares about IRS , If I wanted a smoother ride you'd run on pavement (some like it rough!!!!!!)

 

i haven't really paid attention to milage... i got mine to go 56mph on a flat/straight trail. that was with a little help from the wind. 48mph on the way back. i have about 650 miles on it.