225/40/18 or 235/40/18
 

Hello m8s

I am willing to buy Rota Grids to my GT86 and I am not able to decide what size of tires I want.

Options are 225/40/18 or 235/40/18.

As everybody knows that default size is 215/45/17 and car is quite tailhappy with those. Rota Grids are 18x9.5 so 215 is so narrow for those for me.

Does anyone now how a difference between 225 and 235 affects to tailhappying? Am I able to do powerslides with 235 anymore?

What do you use your car for?
Do you race in any capacity?
What is your current or future torque/power level?


Is "tail happy" good to you or do you want the car to be more controlled?




The above questions will help with the decision, but honestly 225 vs 235 wont change the car that much. The tire compound/characteristics will matter more than the 10mm difference. In fact, the main difference between the two sizes will be which one has better/more tire choices.


All that being said I run 245s on all four corners. Even if I didn't track/autocross my car; that would be my favorite setup now. I run E85 with headers. The 245s are in no way too much tire for the car. Because of the extra grip I can really corner with confidence. So I vote you go 245s.


But, 225 vs 235, your main concern should be which size gives you the tire choice you want to run. Choose a tire, then see which size that tire is available in.


Hope this helps. If this car is strictly a daily driver....then it doesn't really matter. Well you are in Finland....so I hope you have a set of winter tires.

I ran 265s all around on mine at one point and was still able to slide the car without any real difficulties. The car would grip up much easier and the car had to be provoked, but if you know what you're doing, you can still easily induce oversteer.

If you're wanting to drift the car, I'd stay with 17s, as they work much better for this car. If you're just wanting to be able to kick the rear out on ocassion, then a 225 would be fine; though your tires will be stretched a good amount, so just make sure you're aware of that.

I ran a 235/40 on my 18x9.5s I was still certainly able to kick the rear end around but it wasn't as easy as with the 215s. There aren't many options in the 225/40 bracket though so keep that in mind.

I'm using 235 width, Coming from 225, I can't hardly compare the difference. I'm using Nt555r nitto tires by the way. For reference purpose.

Tire Size Comparison
Specification Sidewall Radius Diameter Circumference Revs/Mile Difference
225/40-18 3.5in 12.5in 25.1in 78.8in 804 0.0%
235/40-18 3.7in 12.7in 25.4in 79.8in 794 1.3%

I'm using 235 width, Coming from 225, I can't hardly compare the difference. I'm using Nt555r nitto tires by the way. For reference purpose.

Tire Size Comparison
Specification Sidewall Radius Diameter Circumference Revs/Mile Difference
225/40-18 3.5in 12.5in 25.1in 78.8in 804 0.0%
235/40-18 3.7in 12.7in 25.4in 79.8in 794 1.3%