I was getting the PUP ready for its first outing this weekend when i noticed the spare was a different size than the tires on the PUP.. That's stupid i thought, so now i'm going to fix it. The PUP has 5.30x12 LRC and the spare has 4.80x12 LRB. I called a local tire place and they can get me a 5.30x12 LRC tire for about $30 mounted and balanced using the rim that the 4.80 is on now, not bad i thought, but they also said i need a new innertube for the new size and thats about $14. I thought maybe the innertube would be the same for both sizes but i guess not. So that's my question, i thought a 12" innertube is universal between all the sizes? 1991 Skamper 245C 1997 Pontiac Trans Sport Dad Mom Three Kids!