Need advice on tire size

adamsclubs · 09-22-2011, 02:51 PM

I just ordered Forgestar F14 18x8.5 +32 front and 18x8.5 +26 rear for my non sport 2011 RWD 328i.

Can I use 245/35/18 front and 255/35/18 rear? My first is to reduce weight, second to look better doing it.

adamsclubs · 09-22-2011, 09:58 PM

Anyone? Thanks in advance.

adamsclubs · 09-23-2011, 12:09 AM

I just realized I forgot to state that my current stock setup is 17X8 +34 (I think) and 225/45/17 at all four corners.

remmib · 09-23-2011, 05:30 AM

Why not get a staggered F14 set up?

adamsclubs · 09-23-2011, 08:10 AM

Quote:

Originally Posted by remmib

Why not get a staggered F14 set up?

I have a non sport 328i, wanted to lose weight of the wheels and tires, but also wanted to improve the look. Even though I could get the 18x10 deep concave for the same price, they seemed to fit 335i and M3 with lowered body, more so than my base 3. I don't even have the sport suspension or body kit

The tire sizes I mentioned above are light weight and a little staggered too. However the total wheel/tire diameters are slightly different front to back. Since I have a RWD, I thought it would be fine.

I am hoping the experts here can chime in.

Pcemkr · 09-23-2011, 09:10 AM

Running different sized tires on a square setup is dumb. Pick up a 5mm spacer so you can rotate.

CombatNinja · 09-23-2011, 09:40 AM

You're not gonna notice 10mm of additional width on the rear tyre compared to the front. You're already going wider than stock and the lower rear offset will push the tyre out a bit more. Quit while you're ahead and preserve the ability to rotate tyres for longer service life. If you are really that worried about the appearance of the car, your huge wheel gap is more of an issue than the tyre width, trust me.

adamsclubs · 09-23-2011, 10:24 AM

It is not square setup, as noted above, front and rear wheels have different offsets to be as flush with the fenders as possible so I would not be able to rotate them.

Pcemkr · 09-23-2011, 11:28 AM

Those aren't close to being flush. You CAN rotate them with a 5mm spacer.

adamsclubs · 09-23-2011, 12:31 PM

Quote:

Originally Posted by Pcemkr

Those aren't close to being flush. You CAN rotate them with a 5mm spacer.

Really? I will have to check with them.

In any case I don't plan to rotate the tires. I didn't find it necessary for my stock set. BMW even recommends not to rotate them

Would 225/40/18 front and 255/35/18 rear be better?

krnboy817 · 09-23-2011, 12:59 PM

^ thats what tirerack recomends if you opt for 18s. so im gonna guess that they wont be flush.

adamsclubs · 09-23-2011, 01:09 PM

Quote:

Originally Posted by krnboy817

^ thats what tirerack recomends if you opt for 18s. so im gonna guess that they wont be flush.

The manufacture guarantees the flush fitment. Maybe there are other considerations, I know the wheels need rings.

So is 245/35/18 front and 255/35/18 rear going to be OK or should I be safe and go 225/40/18 front and 255/35/18 rear?

Pcemkr · 09-23-2011, 01:12 PM

Quote:

Originally Posted by adamsclubs

Really? I will have to check with them.

In any case I don't plan to rotate the tires. I didn't find it necessary for my stock set. BMW even recommends not to rotate them

Would 225/40/18 front and 255/35/18 rear be better?

You gain nothing by running different sized tires on 8.5" all around. Again, those specs are not close to being flush. You asked for suggestions, but doesn't seem like you're listening.

adamsclubs · 09-23-2011, 01:30 PM

Quote:

Originally Posted by Pcemkr

You gain nothing by running different sized tires on 8.5" all around. Again, those specs are not close to being flush. You asked for suggestions, but doesn't seem like you're listening.

I was hoping to gain more traction at the rear, would it not improve the handling?

Pcemkr · 09-23-2011, 01:34 PM

You'll ever push your car hard enough for it to make a tangible difference. It's a 230hp pig.

CombatNinja · 09-23-2011, 02:48 PM

More rubber in the rear = more grip in the rear. More grip in the rear of an understeery car makes for more understeer. But hey, if that's your thing...

krnboy817 · 09-23-2011, 03:03 PM

Quote:

Originally Posted by adamsclubs

The manufacture guarantees the flush fitment. Maybe there are other considerations, I know the wheels need rings.

So is 245/35/18 front and 255/35/18 rear going to be OK or should I be safe and go 225/40/18 front and 255/35/18 rear?

hrmm... i doubt people on this forum consider manufacturer's definition of flushness is actually the flushness that people here seek for.

i say... if you havent rolled, and you're not rubbing... your not flush.

adamsclubs · 09-23-2011, 04:20 PM

Quote:

Originally Posted by krnboy817

hrmm... i doubt people on this forum consider manufacturer's definition of flushness is actually the flushness that people here seek for.

i say... if you havent rolled, and you're not rubbing... your not flush.

The custom offsets on the new wheels are determined by Forgestar to be what they called "extreme fitment" so they will be pushed out.

I do experience a little oversteer at a few corners when pushing hard with my current stock square setup, which is why I want to have wider rear tires.

Pcemkr · 09-23-2011, 04:24 PM

My rear wheel sits literally over 1" out further than a 8.5" et26.

adamsclubs · 09-23-2011, 05:09 PM

Quote:

Originally Posted by Pcemkr

My rear wheel sits literally over 1" out further than a 8.5" et26.

Since they said they guarantee the extreme fitment, I will have to wait and see.

Pcemkr · 09-23-2011, 05:19 PM

8.5" et26 is not extreme fitment by any standards.

Why did you order then ask questions anyway?

krnboy817 · 09-23-2011, 06:29 PM

here is a pic of 18x9.5 et30 that i found

so i guess with your set up it "could be" more flush than this one.

09-22-2011, 02:51 PM	#1
adamsclubs Second Lieutenant 5 Rep 223 Posts Drives: 2011 328i sedan Join Date: Sep 2011 Location: CA iTrader: (0)	Need advice on tire size I just ordered Forgestar F14 18x8.5 +32 front and 18x8.5 +26 rear for my non sport 2011 RWD 328i. Can I use 245/35/18 front and 255/35/18 rear? My first is to reduce weight, second to look better doing it.
	Appreciate 0 Tweet Quote

09-22-2011, 09:58 PM	#2
adamsclubs Second Lieutenant 5 Rep 223 Posts Drives: 2011 328i sedan Join Date: Sep 2011 Location: CA iTrader: (0)	Anyone? Thanks in advance.
	Appreciate 0 Quote

09-23-2011, 12:09 AM	#3
adamsclubs Second Lieutenant 5 Rep 223 Posts Drives: 2011 328i sedan Join Date: Sep 2011 Location: CA iTrader: (0)	I just realized I forgot to state that my current stock setup is 17X8 +34 (I think) and 225/45/17 at all four corners.
	Appreciate 0 Quote

09-23-2011, 05:30 AM	#4
remmib General 1568 Rep 29,202 Posts Drives: 2013 F10 520d M-Sport Join Date: Feb 2006 Location: Norway iTrader: (0)	Why not get a staggered F14 set up? __________________ F10 520d M-Sport Alpine White \| HRE P43SC 20x9+20x11 \| Michelin PSS 255/35+295/30 \| KW V3 Coilover \| M5 Front Sway Bar + M550d Rear Sway Bar \| 3DDesign Front Lip \| BMW M Performance CF Spoiler \| BMW M Performance Diffuser \| BMW M Performance Black Grills \| BMW M Performance Pedals \|
	Appreciate 0 Quote

09-23-2011, 09:10 AM	#6
Pcemkr Pro Hater 49 Rep 1,717 Posts Drives: Low and slow Join Date: Apr 2011 Location: DC iTrader: (1)	Running different sized tires on a square setup is dumb. Pick up a 5mm spacer so you can rotate.
	Appreciate 0 Quote

09-23-2011, 09:40 AM	#7
CombatNinja Banned 46 Rep 1,556 Posts Drives: e91 328i, e90 328i, e90 335i Join Date: Feb 2011 Location: United States iTrader: (0)	You're not gonna notice 10mm of additional width on the rear tyre compared to the front. You're already going wider than stock and the lower rear offset will push the tyre out a bit more. Quit while you're ahead and preserve the ability to rotate tyres for longer service life. If you are really that worried about the appearance of the car, your huge wheel gap is more of an issue than the tyre width, trust me.
	Appreciate 0 Quote

09-23-2011, 10:24 AM	#8
adamsclubs Second Lieutenant 5 Rep 223 Posts Drives: 2011 328i sedan Join Date: Sep 2011 Location: CA iTrader: (0)	It is not square setup, as noted above, front and rear wheels have different offsets to be as flush with the fenders as possible so I would not be able to rotate them.
	Appreciate 0 Quote

09-23-2011, 11:28 AM	#9
Pcemkr Pro Hater 49 Rep 1,717 Posts Drives: Low and slow Join Date: Apr 2011 Location: DC iTrader: (1)	Those aren't close to being flush. You CAN rotate them with a 5mm spacer.
	Appreciate 0 Quote

09-23-2011, 12:59 PM	#11
krnboy817 Major 44 Rep 1,011 Posts Drives: 2008 328i coupe Join Date: Oct 2010 Location: DFW texas iTrader: (3)	^ thats what tirerack recomends if you opt for 18s. so im gonna guess that they wont be flush. __________________ driving is poetry in motion.
	Appreciate 0 Quote

09-23-2011, 01:34 PM	#15
Pcemkr Pro Hater 49 Rep 1,717 Posts Drives: Low and slow Join Date: Apr 2011 Location: DC iTrader: (1)	You'll ever push your car hard enough for it to make a tangible difference. It's a 230hp pig.
	Appreciate 0 Quote

09-23-2011, 02:48 PM	#16
CombatNinja Banned 46 Rep 1,556 Posts Drives: e91 328i, e90 328i, e90 335i Join Date: Feb 2011 Location: United States iTrader: (0)	More rubber in the rear = more grip in the rear. More grip in the rear of an understeery car makes for more understeer. But hey, if that's your thing...
	Appreciate 0 Quote

09-23-2011, 04:24 PM	#19
Pcemkr Pro Hater 49 Rep 1,717 Posts Drives: Low and slow Join Date: Apr 2011 Location: DC iTrader: (1)	My rear wheel sits literally over 1" out further than a 8.5" et26.
	Appreciate 0 Quote

09-23-2011, 05:19 PM	#21
Pcemkr Pro Hater 49 Rep 1,717 Posts Drives: Low and slow Join Date: Apr 2011 Location: DC iTrader: (1)	8.5" et26 is not extreme fitment by any standards. Why did you order then ask questions anyway?
	Appreciate 0 Quote

09-23-2011, 06:29 PM	#22
krnboy817 Major 44 Rep 1,011 Posts Drives: 2008 328i coupe Join Date: Oct 2010 Location: DFW texas iTrader: (3)	here is a pic of 18x9.5 et30 that i found so i guess with your set up it "could be" more flush than this one. __________________ driving is poetry in motion.
	Appreciate 0 Quote