[jasonle89]

Hi guys, i don't know much about this topic. All i know is what does offset mean by googling it.

Here is the case, i am currently running 19" all around. My tires size are 245/40/19. Car is not lower. I'm thinking of going 20" staggered concave, just semi concave in front but super deep (if possible) concave in rear. Since i do not want to lower my car, i'm thinking of running thicker tie to cover some of the gaps, maybe 245/40/20 and 275/35/20(saw some member here did this and it looks pretty good). So what offset should i look for? what range of offset that my car can handle without any rubbing AT ALL?

This afternoon when i was at the shop to install my front lip, i notice this and it make me wonder. Please look at the attached photo, that gap right there. Base on my understanding, if i go 20", the wheels are bigger but the tires are thinner, so it will be cancelled out and should be the same diameter for the wheel + tire (if compare to my 19" right now). But as you can see that gap that i pointed at, if i run a thicker tie, it look like it will rub on that thing for sure. Am i right? Then how come some of the member here able to run thicker tire (without using spacer)????

Again, please advice on which offset and how to run thicker tires without any rubbing since i don't want to lower my car (warranty issue)

[.BMW.]

OEM F10 19" front wheels is 8.5x19 ET33 with 245/40-19.

If you look for similiar wheel spec in 20", ie 8.5x20" ET 30-35, and +1 tires 245/40-20 you will be fine.

Tire diameters:
245/40-19 - 679mm
245/40-20 - 704mm

This means that the shoulder of the 20" tire will be 12-13mm higher but not wider on the inside. The clearance to the steering knuckle is about 16-17mm with OEM 19" wheels and tires.

As long as you don't choose higher offset and/or wider wheels 245/40-20 will fit without rubbing the steering knuckle.

[E90Fleet]

OEM 20" tire and wheel sizes for the F10 are

Front
245/35/20 on 8,5J Rim with ET:33 offset

Rear
275/30/20 on 9J Rim with ET:44 offset

[E90Fleet]

Originally Posted by ss0803

OEM F10 19" front wheels is 8.5x19 ET33 with 245/40-19.

If you look for similiar wheel spec in 20", ie 8.5x20" ET 30-35, and +1 tires 245/40-20 you will be fine.

Tire diameters:
245/40-19 - 679mm
245/40-20 - 704mm

This means that the shoulder of the 20" tire will be 12-13mm higher but not wider on the inside. The clearance to the steering knuckle is about 16-17mm with OEM 19" wheels and tires.

As long as you don't choose higher offset and/or wider wheels 245/40-20 will fit without rubbing the steering knuckle.

Doing that would cause the speed sensors to under read by 3.6%
The correct 20" offset is 35, not 40 for that reason

[E90Fleet]

Originally Posted by jasonle89

Hi guys, i don't know much about this topic. All i know is what does offset mean by googling it.

Here is the case, i am currently running 19" all around. My tires size are 245/40/19. Car is not lower. I'm thinking of going 20" staggered concave, just semi concave in front but super deep (if possible) concave in rear. Since i do not want to lower my car, i'm thinking of running thicker tie to cover some of the gaps, maybe 245/40/20 and 275/35/20(saw some member here did this and it looks pretty good). So what offset should i look for? what range of offset that my car can handle without any rubbing AT ALL?

This afternoon when i was at the shop to install my front lip, i notice this and it make me wonder. Please look at the attached photo, that gap right there. Base on my understanding, if i go 20", the wheels are bigger but the tires are thinner, so it will be cancelled out and should be the same diameter for the wheel + tire (if compare to my 19" right now). But as you can see that gap that i pointed at, if i run a thicker tie, it look like it will rub on that thing for sure. Am i right? Then how come some of the member here able to run thicker tire (without using spacer)????

Again, please advice on which offset and how to run thicker tires without any rubbing since i don't want to lower my car (warranty issue)

As mentioned above, a "thicker" tire would cause your speedo and DSC wheel sensors to incorrectly read. They would show you going slower than you actually are going.

[.BMW.]

BMW speedometer always show about 3% higher speed than actual (checked with GPS).

Based on that the speedo will be spot on with +1 tires (245/40-20).

[jasonle89]

So pretty much in conclusion, can I run SDC wheel in the back and semi concave in front?

[jasonle89]

Can someone tell me the order of bad wheel to good wheel. I mean like...alloy is the worst right, then what is next? And also what's about Titanium wheels? Thanks

[SonicEndeavor]

Originally Posted by jasonle89

Can someone tell me the order of bad wheel to good wheel. I mean like...alloy is the worst right, then what is next? And also what's about Titanium wheels? Thanks

It's really cast vs. forged, with cast being the heavier, lower quality of the two. The F10 stock wheels are cast except for the M5 wheels. Forged wheels are typically quite expensive compared to cast wheels, but they are considerably lighter and the corresponding reduction in unsprung weight gives the car slight improvements in quickness and handling.

[jasonle89]

Thank you, what's about Titanium wheel? I'm looking at Stance SC-1. I don't know if that is forged or what, but it said Titanium.

[.BMW.]

Originally Posted by jasonle89

So pretty much in conclusion, can I run SDC wheel in the back and semi concave in front?

To run a concave wheel you need a wider wheel with a lower offset.

Since you also want taller tires than OEM you might get rubbing issues with the fender liner.

Both taller tires and lower offset increase the volume swept by the front wheels and tires during turning.

I wouldn't recommend both taller tires and low offset concave wheels, especially not for the front.

[jasonle89]

Originally Posted by ss0803

To run a concave wheel you need a wider wheel with a lower offset.

Since you also want taller tires than OEM you might get rubbing issues with the fender liner.

Both taller tires and lower offset increase the volume swept by the front wheels and tires during turning.

I wouldn't recommend both taller tires and low offset concave wheels, especially not for the front.

Meaning that if i run 20" with the thin tires that go together with the 20" then concave would be ok?

[.BMW.]

Originally Posted by jasonle89

Meaning that if i run 20" with the thin tires that go together with the 20" then concave would be ok?

That's a better idea if you really want concave wheels up front.

9x20" wheels with offset ~25 and 245/35-20 tires will fit. I'm not sure how concave they will be but it also depends on which specific wheel you choose.

With the rear wheels it's easier to achieve a concave look, 10.5x20" with offset around 35 and 285/30-20 tires.

[SonicEndeavor]

Originally Posted by jasonle89

Thank you, what's about Titanium wheel? I'm looking at Stance SC-1. I don't know if that is forged or what, but it said Titanium.

Brushed Titanium is the wheel color. Yes, that wheel is a monoblock forged wheel.

[The Beast]

Originally Posted by jasonle89

Thank you, what's about Titanium wheel? I'm looking at Stance SC-1. I don't know if that is forged or what, but it said Titanium.

Nice wheel, I also like the SC-8

[jasonle89]

So pretty much I have to decide between concave with thin tires or not concave with thick tires

[remmib]

What wheels are you thinking about?

[493263]

Originally Posted by ss0803

BMW speedometer always show about 3% higher speed than actual (checked with GPS).

Based on that the speedo will be spot on with +1 tires (245/40-20).

Actually, that's not true. I've tested mine several times with many different radar guns.

It's more than just %. There seems to be a ~2mph higher difference to the base before any % is added.

When my speedo says 20mph, I was actually going 17-18 mph confirmed by over 10 different devices.

I think you're so bent on getting these wheels that you're giving yourself more reasons to buy it. Honestly, I think 245/40R20 may look slightly goofy as it will raise your car a little bit. I would stick with 245/35. If you want to eliminate the wheel gap, the best way is to install new springs.

[.BMW.]

Originally Posted by 493263

Actually, that's not true. I've tested mine several times with many different radar guns.

It's more than just %. There seems to be a ~2mph higher difference to the base before any % is added.

When my speedo says 20mph, I was actually going 17-18 mph confirmed by over 10 different devices.

Could absolutely be true. I have only checked at higher speeds.

[jasonle89]

So I end up oredered a set of Stance SC1 witj tires from Nitrous garage. Their siggestion tires size are 245/35/20 and 285/30/20. Does that sound right?

[bake]

Originally Posted by jasonle89

So I end up oredered a set of Stance SC1 witj tires from Nitrous garage. Their siggestion tires size are 245/35/20 and 285/30/20. Does that sound right?

Yes, you will be golden. But once mounted, you will want to lower it to achieve that perfect stance.

[jasonle89]

Lol I know it's tempted but I'll try not to