Rolex Denn

I switched my wheel 17'' wheels to new 18'' staggered oem wheel set.
Now car feels slower to respond when I hit the gas. Is it because i got wider tires or car needs to be coded?

MatthewJ

Heavier wheels will make any car slower, handle worse and stop worse.
There is no coding needed unless you changed the total height of the setup.

Jack Olsen

You'd need to check to see if you changed the outer diameter of the tires. If it's larger, you'll have less mechanical advantage when you accelerate. But it's not always the case to say the overall diameter changes when you go to a larger wheel size. Sometimes it's the opposite. The sidewall ratio of the tire determines its overall diameter.

Keith66

Both excellent points and true. Also something to keep in mind is the "butt dyno" is historically inaccurate. I've been guilty of this on many occasions... you make a change to the car and you become more psychologically aware of every action in comparison to memory. I'm not saying this is your case, but it does happen.

Without having recorded 0-60 or 1/4 mile ETs before and after, it's sometimes very hard to know for sure what impact any changes really have.

I assume the new tires are properly inflated?