can you put 245-55-15 all the way around? i don't like small in the front and big in the back. the back i am not worried about, but the front what is the biggest size you can put in the front and still turn without any problems? can anybody help??  

WELL . CONCERNING TIRES ALONE :

IMPORTANT THING IS CALLED " ROLLING RADIUS". FUGURE OUT

THE ORIGINAL ROLLING RADIUS OF THE ORIGINAL SET UP AND STAY AS CLOSE TO THIS AS POSSIBLE .
REMEMBER THAT 25.4 MM PER INCH .

REMEMBER THAT SIDE WALL HEIGHT IS A PERCENTAGE OF TREAD WIDTH IE ,   SO 245X 55% = 134.75 MM SIDE WALL  HEIGHT.
15 INCH DIAMETER RIMS EQUAL 7.5 INCH RADIUS OR 190.5MM
TOTAL ROLLING RADIUS IS 190.5 + 134.75 = 325.25 OF THE PROPOSED SET UP THAT YOU STATED.
STAY CLOSE TO THIS WITH WHATEVER COMBINATION OF TREAD WIDTH AND HEIGHT .

CONCERNING RIMS :

REMEMBER BOLT HOLE NUMBER , BOLT CENTER SPACING AND OFFESET THESE MUST MATCH CURRENT HUB . SOME PLAY CAN EXIST FOR " OFFSET/INSET" BUT MAKE SURE TO TALK TO DEALER OR RETAILER ABOUT THIS.

NOT AS SIMPLE AS YOU THOUGHT .