Am I missing something? My front tires need bigger spacers to be flush vs rear
 

Everywhere I look it's
10f 15r
15f 20r
20f 25r
Or just even
15f 15r
20f 20r

Etc

I'm so confused
Can someone please explain?
I have 2013 370Z 18" wheels on swift spec R lowering springs

Depends entirely on the offset of the wheels you want to fit.

Lower offset means thinner spacer.

I run Enkei 9.5 x 18 ET35 with half inch (12.7mm) spacer on the front for effective ET22 and inch spacer on the rear for effective ET10.

See photo's for poke .... they are a bit cr4p but should give you an idea at least,.

You say you have OEM 18" wheels but do not say whether they are base or sport ....... let us know which and we might be able to help

Simple, as everyone’s may be a tad different pending camber settings.
Tape a plumb line to fender over centerline of wheel & measure up gaps between string & either sidewall of tire’s or wheel lips.
Be sure you’re parked on level surface w/no wind blowing.
And just get the spacer thickness that fills the gaps.https://uploads.tapatalk-cdn.com/201...12116a3bc4.jpghttps://uploads.tapatalk-cdn.com/201...e0995dd20b.jpg


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I have stock 19's (wheels and tires) on mine, need 27mm upfront and 22mm in the rear with my setup, lowered, camber specs, lf -2.26, rf -2.29, lr -1.77, rr -1.79.

go 25/20 F/R & use the 2mm slip on's if you desire....

Or do 30/25’s.....you’re measuring up 5mm difference.https://uploads.tapatalk-cdn.com/201...9fff3a1f90.jpghttps://uploads.tapatalk-cdn.com/201...1cc88e40ed.jpg


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