so the normal tire size for my 2009 g37 coupe is 225 50 18. and i love drifting so i went and bought 225 40 18 for my car just to burnout. when i had put them on, my dash looked like christmas lights , every light was on and my car could not catch traction to accelerate past 30 mph. immediately i put back the normal size tire and the issue is fixed but i want to know, will my smaller tires that i bought (my 225 40 18) fit in the front , so i can put my current front tires(normal size) in the back? after i burnout these new normal sized ones

 

the stock 225/50R18 is a 26.9 inch diameter. your new tires up front are 225/40R18 that's a 25.1 inch diameter. its to recommended to be within 3% difference in diameter front to rear. your setup would be 6.7% difference in diameter. thta's why your lights are on. your sensors are detecting too much of a difference.

 

thank you that gave me a lot of help for the issue i previously had. but i have yet to put the smaller tires in front. yes when i had them in the back , it was too much of a difference so my car lights came on. but what if i have the smaller tires in the front , should that be an issue ? since the ecu and computer are only wired to the “Rear Wheel Drive “ system? while the smaller tires are in front just nonchalantly rolling on they’re own.

 

it may still trip the lights. I remember I saw a post someone mounted much larger tires in the rear and it happened with them.