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[andawheee]

I have a 2013 128i and the tires that came with the car are 205/50R17. I'd love to get wider tires and have read here and there that it's possible to do this without changing the stock rims. This would be ideal for me. I can afford new tires. I can't afford new rims.

I've read about 225/45R17 being put on stock rims, and I called the local BMW service center to ask about it and the guy recommended not 45R17 but to go with 225/50R17. He said the 45R17 wouldn't be as comfortable as what I have now.

I have no idea what the hell I'm doing here.

I don't have any crazy mods to my car, besides picking out my own rotors and brake pads and bringing it to the mechanic, lol. I'm a gearhead but not that technically savvy just yet.

I'm learning as I go and I have no idea what to do with these tires.

One of my tires has lost half of it's tread due to an alignment issue and needs to be replaced for safety reasons. I need 1 new tire at least and I thought if I'm buying one anyway, why not buy two and start with changing out the rear tires to work towards the aesthetic I'm going for.

I've checked tire size calculators and the 225/50R17 is said to have a Diameter Variance of 3.14% and apparently anything over 3% is no bueno.

The 225/45R17 only has a Diameter Variance of -0.39% which is apparently okay.



I found another site that shows you all the different tire sizes you could technically get.. but is a tire like the 255/40R17 or the 295/35R17 actually an option? When I see how much wider they are, I can't make sense of how the same rim could possibly accommodate such a fat tire but I'm not the expert so .. it's a bit confusing lol.





So what should I do?? Which tire size do I get? I'd love to get something wider and I'm having a hard time knowing what to do because I'm not an expert at this stuff, and I keep hearing mixed opinions.

Your advice would be very much appreciated.

[WrathOTM]

Post a pic of your style of wheels. From your profile pic it looks like style 371.

If so you have a 17 x 7.0 wheels. You can fit up to a 225 width tire. Maybe 235, but I don't think so. I personally run a 215/45R 91W squared setup.

What location/tire is wearing faster than the others?

[WrathOTM]

Also what is your driving style? What do you want from your tires you plan to get?

[gary_william]

I'm running 225/45/17 on all for corners on stock staggered size style 262 wheels, no issues.

[andawheee]

You're right, it's: BMW LA Wheel, Star Spoke 371 (7JX17 ET:47)

After posting this, I did a bunch of research and figured out which rims I had, their dimensions, wheel offset, and all of that.

225 should be a non-issue, 235 probably good, 245-255 unsure without checking all dimensions around the wheel, and taking strut measurements into account, etc.

So much research, lol.

I really just wanted wider tires because I think they look so cool. My brother has a 97 Mustang Cobra with 245 wide tires and they look SICK. I don't think I've ever seen tires and drooled over them before but that's how I felt when I saw his and they're 17" too, they're not even 18" or bigger but the width does make them look so much more substantial. I'll start with replacing the rear tires and do the front ones soon after.



I wanted to see if it was possible to match the aesthetic or at least, come a little closer to it.

I don't take my car to the track, I don't have the funds for that yet, I just try to have fun when I drive to work or when running errands or wherever I go, without getting pulled over by cops. Sometimes I do a little racing on the parkway here and there, I love kicking it into sport mode pretty often. I love fish tailing lol. I have a police radar which helps, so I like to go fast and race when the opportunity presents itself but within reason, without being a maniac

I didn't think to take a pic of the messed up tire when I was taking these the other day but the mechanic told me it's an alignment issue, so at least we know how to resolve that. This is what the tires look like now:




I'd like to do autocross soon but I'm not sure I'll be able to afford it this summer. In any case, traction is necessary b/c I like to test the limits of my car and practice my driving skills. I've experienced BMW's UDE autocross events and from that, try to put into practice what the instructors taught me, so practicing turns at high speeds, not always breaking immediately and feeling the car out, seeing how the car and myself can handle, etc.

[cerealwars]

Bridgestone Turanza RFTs? Looks like you're still on runflats. You'll see a pretty decent jump in responsiveness just by changing out from those.

I wouldn't recommend anything past 225 for a 7" wide wheel.

One more affordable option is to keep an eye out for some wheels that will let you run meatier tires on your car. Check FB marketplace/craigslist. Most E9x wheels are a straight bolt-on, and many of them are 7.5" or 8" wide. They might come with 225s or fatter installed on them already, and they likely won't be runflats. I believe E60 wheels are also an option.

It's easy to drown in research on this topic because there's so much to what makes a wheel/tire perform well. Here's a quick video on how different tire sizes perform that I found interesting, maybe it'll help explain some things -

Quick example - on my car I snagged some wheels/tires for $300. They're not in the best shape but have good tread, a little more width, and will serve me well for a track day. The fronts are definitely a bit close to hitting the fenders as they poke out a little too far.

Stock setup: Style 256 17x7.0 +46 ... 205/50/17
Track setup: Style 285 17x8.0 +34 ... 225/45/17

[benaj]

cerealwars,

Have you run those style 285s on your car yet? I also just picked up a cheap set of style 285 wheels with hopes for winter duty. Before I mount up fresh 225/45/17 snow tires, I tested out with the existing 225/45/17 all season rubber and unfortunately with my stock 128i sport suspension they rub both front and rear. The fronts sadly have violent loud crashing on manhole covers, RR tracks, etc. No go.

Not an option to dial in neg camber on this car at this time to help with fitment so I am back on the hunt for higher offset wheels than +34.

Just wondering your experience, maybe you aren't stock suspension?

[andawheee]

Originally Posted by cerealwars

Bridgestone Turanza RFTs? Looks like you're still on runflats. You'll see a pretty decent jump in responsiveness just by changing out from those.

I wouldn't recommend anything past 225 for a 7" wide wheel.

One more affordable option is to keep an eye out for some wheels that will let you run meatier tires on your car. Check FB marketplace/craigslist. Most E9x wheels are a straight bolt-on, and many of them are 7.5" or 8" wide. They might come with 225s or fatter installed on them already, and they likely won't be runflats. I believe E60 wheels are also an option.

It's easy to drown in research on this topic because there's so much to what makes a wheel/tire perform well. Here's a quick video on how different tire sizes perform that I found interesting, maybe it'll help explain some things -

Quick example - on my car I snagged some wheels/tires for $300. They're not in the best shape but have good tread, a little more width, and will serve me well for a track day. The fronts are definitely a bit close to hitting the fenders as they poke out a little too far.

Stock setup: Style 256 17x7.0 +46 ... 205/50/17
Track setup: Style 285 17x8.0 +34 ... 225/45/17

Hey, luckily it worked out!

I ended up getting 225/45R17 Michelin Primacy MXM4 ZP tires and they're awesome! I got used ones just to play it safe and I'm pleased with my decision. The ride isn't any different, other than I have a lot more traction; It's nice to experience Michelin tires for a change.

I like the run flats; as a chick, it just feels like the safest option. I've had to tow my car at night before and I'm not a fan of the nerves that come with being stranded. It's a safety thing for me, from a perspective that doesn't have to do with the car much at all.

[cerealwars]

Originally Posted by benaj

cerealwars,

Have you run those style 285s on your car yet? I also just picked up a cheap set of style 285 wheels with hopes for winter duty. Before I mount up fresh 225/45/17 snow tires, I tested out with the existing 225/45/17 all season rubber and unfortunately with my stock 128i sport suspension they rub both front and rear. The fronts sadly have violent loud crashing on manhole covers, RR tracks, etc. No go.

Not an option to dial in neg camber on this car at this time to help with fitment so I am back on the hunt for higher offset wheels than +34.

Just wondering your experience, maybe you aren't stock suspension?

Benaj,

Dang dude, that sounds rough. I'm sorry if I led you astray. I bought the style 285s and have had them on my car in two scenarios with no issues. I do drive my car pretty hard, I would expect that if the setup could rub I would have thoroughly tested it.

1.) Stock sloppy base model (comfort) suspension with stock alignment specs. The rears fit fine, but the fronts had some concerning poke. The base model springs may have been too high to allow a rub at the fender. I actually did a track day on this setup. I really suspected it might rub so I brought my stock wheels with me, but ended up having no issues.

2.) I replaced the base model suspension with used OEM 128i sport springs, along with a fresh set of Bilstein dampers and OEM bumpstops. I also added Dinan fixed camber plates (0.7° per side), removed the alignment dowel in the strut tophat, and shoved the tophat inboard as far as possible (maybe another 0.2° per side). Overall still pretty minimal camber but definitely an improvement.

I am really surprised to hear you have fitment problems in the back too. Fitment is near flush, but I never questioned rubbing back there.

Maybe something is up with my car. I've noticed my front fenders almost feel like they have a rolled lip, but it looks like factory paint in there so I assumed BMW just constructs their fenders differently. Different tires in the same size can have slightly different dimensions at the shoulder too. Again, my apologies if I led you astray. That was shortsighted of me to not consider disclosing my suspension setup. I just wanted to share what worked on my car. Guess I have been lucky with my setup.