So I went up one aspect ratio F&B

thecadman99 · 11-12-2012, 12:17 PM

I just installed some Nitto Motivo tires on my 330i sport.
Went to a 255 40 18 in the back and 225 45 18 in the front.

Comfort is better (expected) but it feels a little squirmy (ok, maybe a little expected) in the corners compared to the 255/35-225/40 from the factory.

I'm running 33psi front and 36psi rear.

Since I'm running .5 in taller sidewalls now (tires are 1" bigger diameter vs stock) AND I'm not running RFT should I take up the psi to closer to 36/40?

I'm thinking non-rft would need more pressure, and taller sidewalls might benefit from a few more lbs as well.

What doe you guys think?

driverman · 11-12-2012, 02:55 PM

Increasing the tire pressure makes the contact patch smaller, but I would do it anyway to tighten things up. What is the recommended tire pressure for running at 100 mph? That might be something to try.

Have you noticed a slight loss in performance since the bigger tires are a little heavier and the circumference of your tires is larger, which if effect, makes for taller gearing? It takes fewer engine RPM to move the car the same distance because the tires are bigger. Have you noticed a slight increase in gas mileage?

rorkor · 12-05-2012, 04:06 PM

Nitto's website has RFT replacement pressures listed in the size guide. My staggered set is 33/37 psi over RFT 32/35 psi

11-12-2012, 12:17 PM	#1
thecadman99 Lieutenant 53 Rep 450 Posts Drives: e90 330i 6mt spt bk/bk Join Date: Jun 2012 Location: Virginia iTrader: (0)	So I went up one aspect ratio F&B I just installed some Nitto Motivo tires on my 330i sport. Went to a 255 40 18 in the back and 225 45 18 in the front. Comfort is better (expected) but it feels a little squirmy (ok, maybe a little expected) in the corners compared to the 255/35-225/40 from the factory. I'm running 33psi front and 36psi rear. Since I'm running .5 in taller sidewalls now (tires are 1" bigger diameter vs stock) AND I'm not running RFT should I take up the psi to closer to 36/40? I'm thinking non-rft would need more pressure, and taller sidewalls might benefit from a few more lbs as well. What doe you guys think? __________________ 06 330i 6mt Spt- Eibach Springs, BMW Perf Susp, Supersprint Exhaust, BSW Audio RIP-94 325i 5mt 4d- M3 springs/susp, Z3 wheels, Chipped, Intake, Exhaust= FUN!
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11-12-2012, 02:55 PM	#2
driverman Captain 38 Rep 715 Posts Drives: 2008 328i 6MT - SOLD Join Date: Nov 2008 Location: El Dorado Hills, CA iTrader: (0)	Increasing the tire pressure makes the contact patch smaller, but I would do it anyway to tighten things up. What is the recommended tire pressure for running at 100 mph? That might be something to try. Have you noticed a slight loss in performance since the bigger tires are a little heavier and the circumference of your tires is larger, which if effect, makes for taller gearing? It takes fewer engine RPM to move the car the same distance because the tires are bigger. Have you noticed a slight increase in gas mileage?
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12-05-2012, 04:06 PM	#3
rorkor Second Lieutenant 8 Rep 277 Posts Drives: '11 E90 N52 6MT Join Date: Feb 2012 Location: here iTrader: (0) Garage List 2010 E70 X5 35d [10.00] 2011 E90 328i [10.00]	Nitto's website has RFT replacement pressures listed in the size guide. My staggered set is 33/37 psi over RFT 32/35 psi __________________
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