Hi guys,

I just purchased a second hand '04 sti and the original RE070's are on their way out. I am looking into getting a street/autox tire and have come to the conclusion that I will buy either the Azenis RT-615, RS2 Z212, or Ecsta MX. The last one only comes in a 235/45/17 (no 40 AR).

I am lowered 0.75" all the way around on JDM pink springs with stock struts.

Do any of you have any experience running a 235 width tire from the above three on the stock '04 BBS (7.5") with lowered suspensions?

Should I even consider this or just stick with a 225/45/17 in any of the three above tires? Will the 235 make that much of a difference for handling on the autox/street to offset any other significant problems, e.g. high speedometer readings in the 40 ARs and low speedo readings on the 45 AR?
I guess I am more at risk for a bent wheel with the 40 AR as I do drive into the bronx and manhattan every weekend. The 45 AR sidewall should offer more rim protection, but I gather that an RT-615 in a 40 AR should still be a pretty strong tire for NYC potholes (with adequate high pressure) to protect the stock BBS wheels at the compromise of ride comfort.

What to do guys? Any suggestions?

depends on how serious you are about autox. if you're somewhat serious than the Kumho MX should not be on the list. and if you want to help the short gearing of the STi you shouldn't buy anything shorter than the OE tire, taller has helped me. a 235/45 will fit fine, a 245/45 will probably fit, that's what I'm runnnig on my OE wheels. (Bridgestone RE-01r).. depends on the brand and tread width some also. a 245/40 is ok, but slightly shorter than stock and it doesn't fit very well on our narrow wheels, it's also "harsher" on crappy streets.

My buddy is running the 245/45 Falken's with no issue. None of those sizes will change your speedometer reading more than a few %, so I wouldn't be afraid of any of them. Your BBS wheels are strong and plenty of people are running these sizes on much cheaper wheels, so I don't see that being a problem, either. 245/40 might be a bit of a stretch but not that big of a deal, and 235s will definately be fine.

I would go a little taller on the STI u have a 6 speed, use it, I had the same size on my wrx stg4 330whp and it was snappy but i think with the 6speed it will be really bad. I would go to a 235/45/17. Thats a good size for Daily even a 245/45.

Thanks for the feeback guys.

So I guess the consensus is that I should run a 245/40/17 or 245/45/17? Would my 0.75" drop all around cause rubbing with the taller tire? Would I need to roll my rear fenders and/or use spacers? How would a tire with a soft sidewall like the z212 handle in the the taller tire? I would guess turn in and feel would be sacrificed. I bet the stiff sidewall of the RT-615 would do well with a 245/45/17. This size would also offer rim protection when going into the city. The Ecsta MX is available in both of the above sizes, but I would think that its sidewalls are no where near as stiff as the RE-070s or the RT-615s.

Any further feedback? :confused:

You shouldn't have any rubbing issues, but if anything you may need to roll the fenders a bit. I run a 245/45-16 Kook on a 16x8 on my WRX and love them. The sidewall isn't too terribly soft.

if it were to rub it'd most likely be on the fender liner, not the fender lip. The offset of OE wheel is adequate to support fat tires. Occasionally rubbing the fender liner isn't much of an issue (if at all).

i'd suggest 225/45, 235/45 or 245/45. the 40 series will be too short (imho) reducing ride comfort as well. the 245/40 will give you more rim protection though (curbing/lip protection; more so than the 245/45, either is enough for impact/bending protection) I wouldn't consider any 40 series narrower than 245.

im interested in this thread as my re070s are done and im looking at getting advan neovas. Whats the widest tire one can run on the bbs rims?

i've seen 275 race rubber on 'em. ain't pretty though.

05+ BBS wheels are 8"

btw/fyi, street tire classes (for the STi) are limited to 245

I have narrowed it down to the RT-615 245/45/17 vs the Ecsta MX 245/40/17 or 245/45/17.


DougM, if I interpret your post correctly, I should be able to run the RT-615 in the 245 without having to roll my fenders most likely. Is this correct, taking into consideration that this tire runs wider than its measurement (more like a 255 summer tire)? This would be awesome on autox with really good protection from a bent rim from potholes. The stiff sidewalls should make up for the overly wide size for the 7/5" rim and not affect turn in or steering feel significantly, if at all.

The Ecsta MX also apparently has very strong sidewalls. I just learned this after reading its construction on Tire Rack. This is a quote from the website on this tire ... "The tire's structure includes two wide steel belts that are reinforced by spirally wound nylon to provide excellent strength, uniform ride quality, and high-speed capability while the sidewalls are tuned to resist lateral deflection and to provide handling control and positive feedback." This tire would run about the same size as an RT-615, Z212, or true competition tire in a 235. It wouldn't have the sidewall strength of the RT-615 or competition tire but it seems that it would have a stronger sidewall than the Z212.

Lastly, it seems that a 245/45/17 in the Z212 would be too wide and tall for a 7.5" wheel. I think 225 would be the widest to go on the stock '04 BBS for this tire to really take advantage of its grip and not give up the turn in or steering feel. The sidewalls appear too soft to run any wider on these wheels. It does run wider just like the RE070s and RT-615.

I really don't want to have to use spacers, roll my fenders, or damage my wheels on NYC crappy roads but still use the same tires for street/autox on the stock '04 BBS so it comes down to the first two tires and sizes I mentioned.

BTW, did I mention I am at Cobb Stage 2? I want to get a protune sometime next month. Running rich right now. The RE070s have less tread in the center than the sides (sidewalls were almost perfect before I started autoxing on them twice over the past two weeks). 42 F/ 40 R when I run, which is apparently close to the 40F/40R pressure the previous owner was running these tires on to get 50k miles out of them (hence the increased center wear in comparison to side wear). I am afraid that the tires are out of shape due to these pressures being run on them for so long on the highways. When I come out of turns on the autox (42F/40R) or even the street (35F/35R) for that matter and plant it, the car fishtails!

Also, I guess that the 45 AR in the 245 width will not rub against the strut top or fender liner at all with the 0.75" drop all around on pink springs(especially in the rear)? I figure over some dips at highspeed on the autox or speed bumps, I could expect some brief rear scraping. I could expect this rear scraping with rear passengers, which would not be the case for autox and rarely on the streets/highways.

The Ecsta MX also apparently has very strong sidewalls. Not a chance. They are known in autox circles have soft sidewalls and is one reason they are a light tire. Get the RT-615's if you want the stiffest sidewall of the bunch you are considering.

First, most tire manufacturers spec 235/40r17 to use 8-9.5in rim, though many people have reported that 7.5 is fine. In contrast, 245/45r17 are usually approved for 7.5-9in. It's not only about the treadwidth, also about design and construction.

Also, I have 235/40r17 Toyo RA-1s on ET48 wheels on my '04, and no rubbing even during hard cornering on the track. Since you gain 5mm on the offset using the stock BBS, you will not have problem with a 245 tire on the fender. On the other hand, your tire will get pretty close to the strut on the inside.

We're using a 235/40-17 Hankook on my wife's 17x7 Sentra Spec V wheels. The result? Lots more overall grip, very minimal sidewall squirm. I'm about to put 265/45-16 V710s on my 16x8s, and I can already tell you, it'll give me TONS of overall grip and sacrifice a fair amount of turn-in crispness, but it'll definately be a faster car.

I wouldn't blow off the MX's like that, either. If you aren't concerned with being the very most competetive, they're a decent tire, especially on a heave car. They like to be hot. The sidewalls are soft, but they are sticky. GRM did an article and they had the MX's a few points lower than the Hankooks, which were a few points lower than the Falkens. The decision was easy for me. MX's are the most expensive, and at the time the Falkens were right there with them. It wasn't until I ordered wheels for the 245/45-16 Hankooks that the Falkens dropped in price, and they don't have a wide enough 16" tire for me.

Ok, so I hate to bring threads back from the dead, but after searching, this is the only thread that addressed my personal question...

In my question, has anyone used 235/40/17's on the stock '04 STi BBS rims? I want something more than the 225's I have installed, but I don't want a 235/45. I had them in the past and the increased final drive coupled with the gearing change to '06 took away some of my beloved low-end grunt. Plus, the 235/40 will actually lower my final drive compared to stock.

I'm not so concerned with the short sidewall for comfort, because the F1's are fairly comfortable and quiet. Plus, I drive on smooth state/secondary roads and decent stretches of highway.

So, even though the 235/40's are meant to run on at least an 8" wide rim, does anyone think I'll have an issue on the stock 7.5" width?

it might take some muscle but it should fit (the shorter sidewall will make it more difficult for them to stretch it onto your rim)...

it might take some muscle but it should fit (the shorter sidewall will make it more difficult for them to stretch it onto your rim)...

That was my thought as well. I'm just hoping that aside from mounting, there won't be any issues.

Uncle Scotty ran 235/40 on a 7.5" wheel and liked them, IIRC.

I have 235/40/17 Hankook RS2s on my 04 STi stock wheels.
When new they gripped better than the stock re070s, I'm guessing mostly cause of the extra width. Now that they are worn down to the indicators they absolutely suck. So bad that I get dangerous understeer and oversteer on smooth roads and I just spin through 1st. One drawback about these tires are they make your gearing even shorter! I'm on stock suspension, so of course no rubbing.

I have 235/40/17 Hankook RS2s on my 04 STi stock wheels.
When new they gripped better than the stock re070s, I'm guessing mostly cause of the extra width. Now that they are worn down to the indicators they absolutely suck. So bad that I get dangerous understeer and oversteer on smooth roads and I just spin through 1st. One drawback about these tires are they make your gearing even shorter! I'm on stock suspension, so of course no rubbing.

Thanks for the info. Shorter gearing will be really nice for us 06+ non-sti owners, so that is actually a benefit

Thanks for the info. Shorter gearing will be really nice for us 06+ non-sti owners, so that is actually a benefit

....NOOOOOOO000000000000oooooooooooooooooooooooooo ......

the '06(especially a modded one) has enough torque that a shorter tire is not needed.......I would LOVE to have a 17x8 wheel to put 245/40's or even 255/40's on

....NOOOOOOO000000000000oooooooooooooooooooooooooo ......

the '06(especially a modded one) has enough torque that a shorter tire is not needed.......I would LOVE to have a 17x8 wheel to put 245/40's or even 255/40's on

Well, I guess I tend to disagree. I've run tires both taller and shorter than stock, and well, I prefer the shorter....but I should add that wider is always better.