Keep 225/40/18 or upgrade to 235?

[Fabs]

Hey guys. I have 210k km golf gti 6 dsg that I slightly modified for some ocasional track day (30min stints nothing much) and I’m thinking of putting some oz wheels on. 18x7.5
And the question of going wider tire came up.

Do You guys think the extra cost of the 235 would be worth it?

So far I got some ebc disks and yellowstuff, metalic brake tubes, bc racing br and pilot sport 4.

 

[MrFancypants]

I’ve stuck with 225s for track days and they do just fine. On a 7.5 inch wide wheel your steering might start to feel mushy with much wider tires.

 

[Thumper]

How about Option C.....buy bigger wheels. LOL

Here's some interesting reading. When I read part 1 when they first did it I really struggled, it goes against all conventional wisdom, bigger tires are ALWAYS better. Heck I've got 235s on my R and actually bought 888Rs in 245s for it which don't fit at my low setting currently, and I run 265s on the TTRS............but makes sense that the tire is only as good as the platform it's mounted on and sidewall performance is most important. Just like "stretched" 215s on a 10" rim handle like crap tires too wide for the rim width will perform poorly as well.

My Allroad came with 245/45s on a 7.5" rim, even after lowering it I was surprised how soft and dull the ride and steering still was but blamed the electric rack and soft sway bars Then I put those 888Rs in 245/40 on an 8" rim on it as a test and even normal driving the steering response was a massive improvement, shrinking that sidewall and giving it a better angle to work made a huge difference. Made me completely rethink my plans for a wheel and tire upgrade on it.

Tire rack: In Search of the Fastest Tire and Wheel Width Combination

So what did we learn? The key takeaways are that in the dry, a wider tire does not automatically mean faster lap times. Using a wheel width that properly supports the tire will provide faster laps than a wider tire with very little wheel support. We saw this in our testing - the 215/45R17 tire on the 9" wide wheel was noticeably faster than the much wider 245/40R17 tire on the 7" wide wheel. That's not to say tire width doesn't matter, though, as the 225/45R17 combinations were all faster than the 215/45R17s. The 245/40R17 on the 9" wide wheel was very close to the 225/45R17 on the same wheel. If we could fit a 10" wheel width on our test cars, the pattern seems to indicate a 245 on a 10" would have been the fastest combination of all.

 

[Fabs]

So guys! I’ve decided to go up from 225/40/18 to 235/40/18
The question is. Will it rub? Does a 235/40 wheel fit?
Also I have it slightly lowered (put some BCRacing BR series coilovers on it)

Also the wheel size would be 18-8 yeah?
Anyone with this experience?

 

[Fabs]

So I bit the bullet and got myself some 18x8 japan racing wheels with some nankang ns2r rubber 235/40/18.
It only rubbed with unexpected deep potholes and on track under some heavy compression.
I’d say it’s definitely worth it if you track your car. Its got more than enough grip for a stock engine.
I’m running BC Racing BR suspension which I had to lift a bit coming from the 225/40. I can give hight measurements if anyone wondering.