use this so you can compare, pretty helpful...

Custom rims, wheel tire packages for your ride - RIMSnTIRES.com

i go 245/40/18 on the stock wheel, tracked and autoX no issues

So, tires are bought and here: 245/40/18

I am getting the Work Emotion CR Kiwami in 18x9.5 in Bronze to go on my Velocity Red.

Which one should I get, +38 or +30??

Wheels: Wheel 1 Wheel 2
Wheel size 18x9.5 ET 30 18x9.5 ET 38
BackSpace 163 mm (6.4'') 171 mm (6.7'')
8 mm (0.3'') deeper.
Rim Lip 8 mm (0.3'') wider
Typical Weight ~ 31 lbs / 14 kg ~ 31 lbs / 14 kg
Tires: Tire 1 Tire 2
Tire size 245/40-18 245/40-18
Section width 245 mm (9.6'') 245 mm (9.6'')
Sidewall 98 mm (3.9'') 98 mm (3.9'')
Tire diameter 653 mm (25.7'') 653 mm (25.7'')
Rim sizes 18x7 to 18x9 18x7 to 18x9
Circumference 2050 mm (80.7'') 2050 mm (80.7'')
Revs per mile 784.9 784.9
Typical Weight ~ 24 lbs / 11 kg ~ 24 lbs / 11 kg
Wheel+Tire Weight ~ 55 lbs / 25 kg ~ 55 lbs / 25 kg

drive it right, park it low
 

This may not be the best thread, but it fits. In the past, I was always a low rider kind of guy that was torn with performance in my blood. Does anyone have a good suggestion as to which, or if there's a good set up for air ride? I'm just looking for the best of both worlds while still feeling safe to take it sideways when the mood is right... there has to be a heavy duty bag out there.