Ok last night i got a flat on my 20" rear pasenger side and instead of carrying the dummy tire i carry one of my factory 17'' tires for a spare. So i changed it out and get on the road and get up to like 25 and my SLIP light starts blinking so im like WTF so i let off the gas a lil and step on it again i have no power and my SLIP light is still blinking. So long story short i turn the VDC off and ride home like that but i dont understand why it did that is it rotatsional mass like the computer telling the car that the 17'' wheel is spinning faster than the 20" wheel and tripping the SLIP or what????????

 

Outside diameter of the 17" spare was more than likely quite different compared to the 20" tires. Another example of tire diameter being important on these cars and what can happen.

 

yup, your vdc thoght that the 17in tire was constantly slipping (cause it's rotating more than the other three 20in because of smaller diameter)...so it cut out power
When you turned it off, you were fine but your car was prolly leaning to one side a little cause of the shorter height of the 17in