My sp800efi X2 DLX get very good gas milage, however I don't know what a sp500efi gets. But, my 800 gets better than my bf750 which is carb. As long as I don't " hammer" on it, I can ride all day long. I am not sure what the total miles to a tank is, but I will try to check it this next week when we go on a long ride.

 

I don't suppose you have ever raced the two in say a 300 footer? Not that it would be a deciding factor for me at all, but I am curious. I ride with a BF and he can really move (the only guy faster in our group has an 800 Outty). If I can get his fuel milage I think I'd be O.K with that.

 

I have raced my bf750 with my brother on the brute and even though my sp800efi X2 DLX is extremely powerful and fast, it was no match for my bf750. We raced over 200 yards and he took me by aout 4 quad lengths. But, remember that the X2 weights more than the regular sportsman 800 and my bf750 now has the moose ignition module and jet kit. I have raced my bf750 against a regular sp800 before I put my ignition and jet kits on and it was closer. I still won but it was about 2 quad lengths. But, no matter what, my sp800efi X2 DLX will out pull my bf750 and mostly b/c of extra weight for traction. And, it rides better than anything I have ever rode.