I have a 2008 sportsman 500 EFI, and I also have a 2007 sportsman EFI. I seem to get way worse gas mileage out of my 2008 rather than my 2007. I have 386 miles on my 2007, and have 278 miles on my 2008. My 2008 should be broke in by know wouldn't you think? I have changed my oil 3 times already on my 2008. At least 4 times on my 2007 sportsman. Why am I getting way worse gas mileage with my other Polaris? I know they call for different weights of oil from Polaris premium 4 for the 07, and the 08 calls for ps-4 plus. I don't know if I should take it in for servicing or if I should run amsoil 0-40w and see if it helps.

 

I would start by checking the air filter.

 

I just put a new K and N air filter in about 15 miles ago. It made no difference. I even put in a new spark plug. I am afraid to take it to the Polaris dealership for service because they are just gonna give me the run around.

 

I think the gas mileage sucks. My 800 uses more gas than my pickup, and my 500 isnt much better. They are both EFI. I chalk it up to slow trail riding cause the mileage sucks. I'll have to time it out and see how many hours I get to a tank. Maybe I should invest in an hourmeter like they put on equipment and scrap the odometer.

 

why have you chaged the oil so many times in such short time? really that milage isnt really even broke in as of yet. i think the older models get better milage then the new ones for sure and it might be that the computer needs to be reflashed for a leaner mixture but this would be just a guess.

 

"I know they call for different weights of oil from Polaris premium 4 for the 07, and the 08 calls for ps-4 plus"

How would that be? The only change to the 500 fuji motor since it came out in 96 was a cam change in 98 for Scrambler and 01 for Sportsman other than that just a fuel delivery change,34mm,40mm or EFI.

Nothing there that effects the need for a oil weight change.

Do both ATV have the same tank size, Polaris loves to make there tanks smaller on the Sportsmans.

02= 5.25 gal tank
04=4.75
06=4.25
07=4.13
08=4.1

My lawn more probably has same tank sizes as a 09 by now. LOL

 

My lawn mowers have 12 gallon cap (2 6 gallon tanks)!!!

 

I see the new XPs have the 5.25 gas tanks again, hope Polaris does not shink them down every year also.LOL

 

As far as I know the 2007 and the 2008 both have 4.13 gal fuel tanks. I just changed my oil with amsoil 0-40w. Were gonna do some riding this weekend. I'll fill em both up with gas and well ride together and I'll see how much better it'll do as far as gas mileage.
I'll let you all know how I did with my gas mileage. Both of these atv's are bone stock with no modifications.