How overkill is 245/35 vs 225/40 tires?

[toast]

I had 245s because I needed them on the back for Edelbrock level power and because they looked great on the 17x9 wheels I ran.

At stock power levels you seriously don't need them, I would think they have to be slower around a track unless you are an expert-level driver, they are more expensive and they take away from the playfulness of the car - just makes the steering feel heavier. If you are moving to 18's you clearly don't care about any of this, you just want the look so I would get the 245.

[GrabTheWheel]

OP, you failed to mention what you intend to do with the car? If you want to autoX or track 245’s wouldn’t hurt but also wouldn’t be necessary if you’re just starting out. If it’s a car only for the street I wouldn’t add more tire with stock power unless it’s just for looks, will make the car less fun in my opinion.

For those arguing that more tire is slower at the track with stock power you are mistaken. Vorshlag tested this by putting 315 Hoosiers at all 4 corners with stock power and the car was most definitely faster at the track, checkout their blog. More tire is almost always faster, even if you have minimal power.

[mrhayes1]

IMO, 245 is a bit overkill for the street in terms of width/grip; assuming of course that you go with a good high performance summer tire. If you buy crap tires a 245 may not even be that much in terms of grip.

I would never go with a 225 on an 8.5 inch wheel as I don't care for that look, too stretched for me and too small of a tire. Personally, I would never put anything smaller than a 235 on a 8.5 inch wheel just because of the looks alone. I like a big tire look.

As someone said above, the performance increase going with a 245 as opposed to a 235 or 225 will be negligible assuming they are both good summer compounds. You are likely talking a couple miles per hour increased corner speed at best. And then you need to take into account the increased drag which means less top end speed, etc., and reduced steering feel that comes with a wider tire. However, I usually opt for a larger tire in terms of looks. Also, one thing to keep in mind too is a larger tire, although maybe not needed often for regular grip, will generally be harder to overheat than smaller tires. Meaning a 245 on the track may not perform any better than a 235 or 225 for 1-2 laps, but after many laps, you could perhaps see a difference as they will be less likely to overheat and get greasy. Just something to think about. In other words, in stock power on the normal street a 245 is a lot of grip and arguably a hindrance, but on hard canyon runs after a while of driving I am glad I have them.

[Skyehigh55]

Sorry to revive this post. I will be choosing to go with 17x8 with 225/40 MPS4S instead of 18x8.5’s. Being able to cut down more weight (about 4lbs a corner with the new planned setup) anywhere on the car reasonably while getting the fitment I desired is my goal for a couple more years until said car is paid off. Maintaining the nimble characteristics of the car for DD’ing was my priority as it will eventually see track days and even more spirited driving.

I will be staying NA as I would much rather enjoy NA reliably instead of run into FI headaches. Thanks for all the advice! I really appreciated reading all the insights.

[Capt Spaulding]

You might consider 45 A/R tires instead of the 40s. The additional air volume will soften sharp edged bumps and offer a bit more protection against potholes. Generally, at no discernable damge to handling. I suspect Sebastian would be able to telll but not a tiro like me.

[Skyehigh55]

Originally Posted by Capt Spaulding

You might consider 45 A/R tires instead of the 40s. The additional air volume will soften sharp edged bumps and offer a bit more protection against potholes. Generally, at no discernable damge to handling. I suspect Sebastian would be able to telll but not a tiro like me.

Typo on my behalf. Yes, I will be going 225/45 MPS4S after I run down the stock primacys on the new 17x8 RPF1's. Not really in a rush to change tires yet since I'm currently just below 15k miles with plenty of tread left. Really interested to see if I can "feel" the 5lb weight difference per corner difference while on stock rubber.

[AKITA]

Originally Posted by Skyehigh55

Typo on my behalf. Yes, I will be going 225/45 MPS4S after I run down the stock primacys on the new 17x8 RPF1's. Not really in a rush to change tires yet since I'm currently just below 15k miles with plenty of tread left. Really interested to see if I can "feel" the 5lb weight difference per corner difference while on stock rubber.

I think you've chosen well for DD. The MPS4S will probably show itself in feel more than weight. I don't really like the primacys. I think the cars rear end can get all over the place with them but if someone likes that ok. 225/45 MPS4S will still be playful if you want it but probably a little more planted in and out of corners. I haven't owned the MPS4S so don't know the ride, but from what people say, I imagine it's pretty good as well.