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[DarkRider23]

Sorry for what might seem like a dumb question, but I just ordered some new EC-7s and need to figure out the tire size.

New set up is going to be

19x8.5 ET 35, 19x9.5 ET43

A 235/35 and 275/30 set up would have diameters of 25.48" and 25.5" respectively or about 1.5% off from stock.

225/35 and 265/30 would drop the difference from stock in the rolling diameter to ~0.6% and ~0.89%.

Am I correct in assuming that I would be better off going for the 225/35, 265/30 set up since they're closer to stock or is what matters the new diameters being relatively close to each other and not stock set up?

[ferocity02]

Larger than stock shouldn't be an issue, your speedo will be off a little but that's it I think. Hell, taller tires will make your speedo more accurate since its like off by 3mph from the factory.

It's good to keep the tires close in the same diameter especially if AWD.

[330xtrai]

Originally Posted by ferocity02

Larger than stock shouldn't be an issue, your speedo will be off a little but that's it I think. Hell, taller tires will make your speedo more accurate since its like off by 3mph from the factory.

It's good to keep the tires close in the same diameter especially if AWD.

I agree. the only thing that matters is the rolling diameter between wheels if you're x drive. also check for fitment which doesn't seem like an issue with those sizes and offsets. if you want something meatier go with the bigger sizes.

[bmw325i]

+1 on both of those answers. It is more important that your front and rear are close in diameter. I wouldn't go smaller than stock because then the speedometer will be less accurate.

[DarkRider23]

Thanks for all the answers everyone. I'll probably be going for the bigger tires. The speedometer being off a bit isn't a big deal since it's already off to begin with. I could definitely use some meatier tires for NJ. Every little bit helps.

[Aashenfox]

It IS an issue and I can't believe I'm the only one saying this every time it comes up. You will work the brakes and engine significantly harder asking them to start and stop a car on larger diameter tires. Its a simple matter of physics. Whether its significant enough to cause a significant amount of extra wear over a period of time is debatable, but it just seems like a silly thing to do to me, no offense, I know you were asking for opinions, right or wrong, that's mine.

[bmw325i]

Originally Posted by Aashenfox

It IS an issue and I can't believe I'm the only one saying this every time it comes up. You will work the brakes and engine significantly harder asking them to start and stop a car on larger diameter tires. Its a simple matter of physics. Whether its significant enough to cause a significant amount of extra wear over a period of time is debatable, but it just seems like a silly thing to do to me, no offense, I know you were asking for opinions, right or wrong, that's mine.

Lmao like 1/2" or less is going to make a noticeable difference on any of that.

[Aashenfox]

Yeh in this particular case you are right, I didn't read the op properly, the difference he's talking about is less than half an inch by the way. I thought they were talking about upsizing, which is less advisable (running a 40 instead of a 35, for example). You could have posted that you din't think a hjalf inch makes any difference, and I would have checked my statement against the OP and probably agreed with you. In stead you tried to call me out and put a laughing smiley where I'm discussing something serious that not many people are aware of. Basically, you're very aggressive for someone who didn't know how asymmetrical tires work. I could have laughed at you in the other thread where you embarrassed yourself, but I didn't, I patiently tried to explain, grow up dude.

[bmw325i]

Originally Posted by Aashenfox

Yeh in this particular case you are right, I didn't read the op properly, the difference he's talking about is less than half an inch by the way. I thought they were talking about upsizing, which is less advisable (running a 40 instead of a 35, for example). You could have posted that you din't think a hjalf inch makes any difference, and I would have checked my statement against the OP and probably agreed with you. In stead you tried to call me out and put a laughing smiley where I'm discussing something serious that not many people are aware of. Basically, you're very aggressive for someone who didn't know how asymmetrical tires work. I could have laughed at you in the other thread where you embarrassed yourself, but I didn't, I patiently tried to explain, grow up dude.

I admitted I was wrong in the other thread I was thinking directional tires. Anyways I was just making a joke hence the laughing smiley. I apologize if it offended you. To me it just sounded like the typical "Use a non BMW part and your car will self destruct" lol.

[Nitrousbird]

Originally Posted by Aashenfox

It IS an issue and I can't believe I'm the only one saying this every time it comes up. You will work the brakes and engine significantly harder asking them to start and stop a car on larger diameter tires. Its a simple matter of physics. Whether its significant enough to cause a significant amount of extra wear over a period of time is debatable, but it just seems like a silly thing to do to me, no offense, I know you were asking for opinions, right or wrong, that's mine.

Yet people with trucks do 20x greater diameter changes without issue.

[Aashenfox]

Originally Posted by bmw325i

I admitted I was wrong in the other thread I was thinking directional tires. Anyways I was just making a joke hence the laughing smiley. I apologize if it offended you. To me it just sounded like the typical "Use a non BMW part and your car will self destruct" lol.

Sorry man, I got the wrong end of the stick with the laughing smiley.

I see people often saying that upsizing 4% is no issue, and they're entitled to that opinion, I just think its a bad idea, especially with the faster cars, as the extra torque on a bigger wheel is just like using a longer lever on a wrench, sure you get more purchase, but you're also a lot more likely to break the nut or the wrench, I'm sure you know what I mean. Not a BMW thing, nor am I a BMW DE policy worshipper, I think this goes for all cars.

And to the guy that said about trucks, yeh, they are built a lot stronger and have torquier engines, but don't believe for one second that those truck drivers haven't compromised their vehicles, just like when we use aggressive offsets and ride heights, its a trade off they are happy with, that's all.

[bmw325i]

Originally Posted by Aashenfox

Sorry man, I got the wrong end of the stick with the laughing smiley.

I see people often saying that upsizing 4% is no issue, and they're entitled to that opinion, I just think its a bad idea, especially with the faster cars, as the extra torque on a bigger wheel is just like using a longer lever on a wrench, sure you get more purchase, but you're also a lot more likely to break the nut or the wrench, I'm sure you know what I mean. Not a BMW thing, nor am I a BMW DE policy worshipper, I think this goes for all cars.

And to the guy that said about trucks, yeh, they are built a lot stronger and have torquier engines, but don't believe for one second that those truck drivers haven't compromised their vehicles, just like when we use aggressive offsets and ride heights, its a trade off they are happy with, that's all.

I do agree that 4% difference or 1 profile higher is too much. Going up a size or 2 in width just makes a small difference in height and these are common sizes with aftermarket wheels. You are correct on your reasoning though if the tire or wheel size is way off. No hard feelings just a misunderstanding.

Here is a laugh at someone else's expense for you
http://www.e90post.com/forums/showth...highlight=donk