Best tire size for 17x8.5 +30

jpx

jpx

Well-Known Member
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North NJ
Vehicle Model
Si CBP
Body Style
FB6
I've searched on this forum but could not find a definite answer. The thread I found with the same wheel specs didn't have answer for tire size. Please help!

I just purchased a set of RPF1 17x8.5 +30, and I'm dropped on Eibach Pro Kit (1.2" drop). What tire size would be best for daily driving (+ long distances) for work, cause no rubbing, and require no fender work?? I also don't want to have to stretch the tire if not required

235/45?
245/45?
 
Hey jpx....

Nice wheels! As far as tire sizes go you have a few options that will fit that wheel. I would go with either of these two sizes:

225/45 - best for all around driving and your speedometer will slightly faster. Speedo says 60, you're going 61.

235/40 - best performance size but speedometer is slightly slower. Speedo says 60, you're going 59.

The 235 width is great for performance but if you're DD-ing and commuting a lot the extra tread will definitely hurt your mileage. With the 8.5" you can probably get a 225 on there with no problem and no stretch. A 225 has a 9" section width so it will be very close to exactly the same size as your rim. As far as rubbing it's hard to say with the +30 but I doubt you would have any. We currently have a 225 on my wifes 8.75" wheel and it's a baby stretch on there. Just enough that you have to look at it to see it.

Again, something to keep in mind is that different tires that say "225" on them are not all the same width exactly. I had a set of Dunlops in 225 that didn't rub and got a new set of Bridgestones in the same size and they do, just barely. Well, only if the car has some extra people in it. Hahahah. Rear passenger one too. None of the others.

I would love to recommend you the 235/40 size but it sounds like the 225 will be a better choice for what you need.

I would shop for a 225/45 tire. There are a ton of choices in that size. A lot of guys run the 215 width with some stretch to avoid rubbing but I think you can go up a size. The 215 will definitely be a stretch on that wheel.


This is the 225 on an 8.75" wheel. You can see it stretch a little on the rear wheel. The sidewall has a tiny bit of angle to it.
kffj.jpg
 
Thank you for the information! I would definitely prefer to get the most mileage I can as I do drive a lot, so I think I'll go with 225/45.

I have a set of Falken Ziex ZE-912 235/45/17 tires but 2 of them need to be replaced. I would like to purchase a set of 225/45 but I can only afford 2 new tires at the moment. If I run 2 new 225/45 tires in the front and the 235/45 in the rear for 1-3 months (until I can purchase the other 2 new tires), do you think it will be a problem?
 
nah. It'll be a little raked looking maybe but all the mileage/speed is calculated on the fronts, I think, so you shouldn't have any issues. Are you putting those tires on the new wheels? It's possible you'd rub the 235s in the rear but if they are getting replaced soon hopefully it would only be very very slight rubbing over large dips and bumps.
 
I decided to buy 2 new 235/45 tires since my other 2 235/45 still have 8/32 tread. Thanks for your help!
 
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Yeah, that tire size is definitely not ideal. Buying the correct size tires and replacing the 235s when you can is the better option. You are concerned about rubbing and the 235 will only make the probability of rubbing much greater. You will be going faster than your speedometer says and you are adding almost 10% more height to the sidewall of the tire. This will also reduce the amount of torque you have as it takes much more force to turn a taller tire.
 
What about those who run evo 8/9 wheels with 235/45?? They're fine with them
 
Depends on offset and drop. Also like I said, a 225 from one company is not necessarily a 225 from another. It's just chance. You might be fine but you might rub a little. It's not a super bad size or anything. Just not ideal.
 
jpx said:
What about those who run evo 8/9 wheels with 235/45?? They're fine with them
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like i said, your base on your decision on your budget, people that buys evo wheels use the take off tires that comes with it...

it will work, but it's the wrong size... been tuning honda for 25 years, proper is always better..

235/45-17
235.jpg

235/40-17
235 1.jpg
 
The 235/45 are definitely taller and look more meatier, and the 235/40 look perfect. I wish you had posted that earlier in the day. So then what appropriate size wheel would these 235/45/17 tires fit on?
 
The meaty tire look was starting to grow on me, too.....
 
team3d said:
proper size is 17x8 with 225/45-17 or 17x8.5 with 235/40-17

235/45-17 is too tall, your buying this size base on budget, not what's best for your need.
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Just want some clarification on tire sizes. I’m running an what I feel is an uncommon wheel setup. Most people have 17x8 or 8.5 but mine is in the middle with a 17x8.25 +32. Currently running the stock size 215/45 cuz I just wanted to rush and get wheels. Looks great! But people saying 235/40 is good and will fit within these ranges but my wheels are hella flush with very slight poke. I’m scared if I replace my tires with 235/40 it will poke out too much since it’s 20mm wider tire. This how it sits right now I want something functional and good performance while still comfortable for a DD. 235/40 comfortable?
 

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The 235 will be 20mm wider overall*, but you’d be dividing that across both sides of the wheel. So, you’d be 10mm closer to your fender and 10mm closer to your suspension.

10mm is .39 inches or like 3/8ths of an inch wider each direction
 
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