[Matt]

How much bigger is a 225/40/18 then a 215/35/18? I found a good deal on a set and I need new tires so I wanted to see if they would fit on my 200sx. Thanks

 

[NismoNx2000]

18's???? OH dear, thats gonna be a harsh ride...are those gonna fit in your wheelwells???

 

[PlanoSER]

that sounds like it's gonna be off quite a bit coz u up sized in the width and profile.. check www.tirerack.com they should have a tire size calculator. if not do a search on google.com for a calculator.

 

[hpro123]

How much bigger is a 225/40/18 then a 215/35/18? I found a good deal on a set and I need new tires so I wanted to see if they would fit on my 200sx. Thanks

Although your question as asked does not make much sense here is an answer...

225.40.18 are compared to 215/25/18:

+1.16inches in total diameter (or +29.8 mm )
+0.4 inches in width
+0.58 inches in sidewall height (if you want to measure visually on the car)

This is +4.85%... Way too much...

Chris