Spare Tire Size

[lexuseng]

I had to put on my spare for the first time the other day on my 2001 GS300 and found the spare to be a different size. The previous owner upgraded to a wider lower profile tire (225/55). The spare is a 215/60. I replaced the flat rear tire and then started thinking if the different size would screw up the traction control. I could have switched it to the front but was too lazy. Anyone know what this would do? Should I keep the spare or keep one of my old tires as a spare when I buy a new set (very soon)?

[92Lex]

225 is thw width of the tire and 55 is the % the height of 225. So 215/60 is about right.