Tired of 18's, want to downgrade to 17

Bbox · 12-11-2013, 04:07 PM

Right now I have a 2006 330 with the Style 162 staggered 18" rims. But at least 2 or 3 of them are bent. So I want to downgrade to 17" rims, specifically the Style 286 from a newer E90.

Old --------------------> New
Front 225/40-18 -----> 225/45-17
Rears 255/35-18 -----> 255/40-17

The rears would have the same rolling diameter, but the fronts would be a tenth of an inch smaller in diameter. Would this screw up the FTM tire monitors? (I have FTM, not TPMS).

Also, the rims are the same width (8/8.5 staggered), but the new ones have different offset (34/39 instead of 34/37). This means the rears would be pushed in by 2mm. Would I even notice this?

Route 16 · 12-11-2013, 04:27 PM

Quote:

Originally Posted by Bbox

Right now I have a 2006 330 with the Style 162 staggered 18" rims. But at least 2 or 3 of them are bent. I want to downgrade to 17" rims, specifically the Style 286 which are staggered like mine.

Old --------------------- New
Front 225/40-18 -----> 225/45-17
Rears 255/35-18 -----> 255/40-17

The rears would have the same rolling diameter, but the fronts would be a tenth of an inch smaller in diameter. Would this screw up the FTM tire monitors? (I have FTM, not TPMS).

The rims are the same width (8/8.5 staggered), but the new ones have different offset (34/39 instead of 34/37). This means the rears would be pushed in by 2mm. Would I notice this?

FTM, TPMS, aren't they the same? I don't think '06's have a low tire pressure indicator anyway. Either way, it shouldn't effect FTM.

I was fine with +38 rear offset, shouldn't be noticeable.

Bbox · 12-11-2013, 04:41 PM

The FTM system on the 2006 measures the rolling diameter to detect whether there's been a pressure loss.
It doesn't actually measure the tire pressure, like the TPMS system does.

VMRWheels · 12-12-2013, 02:20 PM

The tire sizing you have selected looks fine, so you shouldn't have any issues.

Gary@TireRack · 12-13-2013, 09:33 AM

I agree with the above two posts.

12-11-2013, 04:07 PM	#1
Bbox Enlisted Member 4 Rep 48 Posts Drives: 06 330i sedan Join Date: Aug 2013 Location: Bay Area iTrader: (0)	Tired of 18's, want to downgrade to 17 Right now I have a 2006 330 with the Style 162 staggered 18" rims. But at least 2 or 3 of them are bent. So I want to downgrade to 17" rims, specifically the Style 286 from a newer E90. Old --------------------> New Front 225/40-18 -----> 225/45-17 Rears 255/35-18 -----> 255/40-17 The rears would have the same rolling diameter, but the fronts would be a tenth of an inch smaller in diameter. Would this screw up the FTM tire monitors? (I have FTM, not TPMS). Also, the rims are the same width (8/8.5 staggered), but the new ones have different offset (34/39 instead of 34/37). This means the rears would be pushed in by 2mm. Would I even notice this? Last edited by Bbox; 12-11-2013 at 04:22 PM..
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12-11-2013, 04:41 PM	#3
Bbox Enlisted Member 4 Rep 48 Posts Drives: 06 330i sedan Join Date: Aug 2013 Location: Bay Area iTrader: (0)	The FTM system on the 2006 measures the rolling diameter to detect whether there's been a pressure loss. It doesn't actually measure the tire pressure, like the TPMS system does.
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12-12-2013, 02:20 PM	#4
VMRWheels BimmerPost Supporting Vendor 2038 Rep 25,989 Posts Drives: BMW Join Date: Jun 2007 Location: Anaheim, CA iTrader: (4) Garage List 2013 BMW M3 [10.00] 2015 BMW M4 [0.00] 2013 BMW F30 [0.00] 2014 BMW F22 [0.00] 2013 BMW F06 [0.00]	The tire sizing you have selected looks fine, so you shouldn't have any issues. __________________ VMR\|Wheels \| 714.442.7916 \| sales@velocitymotoring.com \| www.velocitymotoring.com \| facebook \| flickr \| Instagram
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12-13-2013, 09:33 AM	#5
Gary@TireRack Moderator 369 Rep 4,745 Posts Drives: Formerly 1995 M3 Join Date: Oct 2006 Location: South Bend, IN, Tire Rack HQ iTrader: (2)	I agree with the above two posts. __________________ Gary. Tire and Wheel Forum Moderator. Tire Rack Sales Rep Gary@Tirerack.com http://www.tirerack.com/a.jsp?a=AH8&url=index.jsp Please refer to 'Gary/E90 Post' as your previous contact when you order online to help support this forum.
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