Need advice on off-sets

When i get my VR-4 the first mod(s) i'm going to do is wheels and tires. So here is what i'm looking at on wheels:

5Zigen FN01-RC 18x8.5 in front and 18x9.5 in the back.
Volk LE37T18x8.5 in front and 18x9.5 in back.
Gram Light 57pro in 18x8.5 front and 18x9.5 in back but i'm not sure if i can get them in 8.5 and 9.5 so maybe 8.0 and 9.0.

I will be getting Tein FLEX coil-overs and maybe a break upgarde.

Now here is the question. What off-set's do i need for the 18x8.5's (front) and 18x9.5's (back) and also for the 8.0 and 9.0?

Tire Sizing Formulas
Speedometer and Odometer Variances Page built by Eric Bowden: [email protected]
Calculations using Dodge Stealth and Mitsubishi 3000GT factory tire sizes for standards

Variables to be changed Calculated fields and constants: DO NOT CHANGE these values!
Total Tire External Constant Constant Odom Trav Variance at Variance at Speed Var
Width (mm) Profile% Wheel " Wheel (mm) Profile (mm) Height (mm) Circ (mm) Mile (mm) Rev/Mile 60 Miles @ 60 Miles 1000 miles 30k Miles @ 60mph

Factory 245 40 18 457.20 98.00 653.20 2052.09 1609344 784.25 96560640 59.99 999.90 29996.91 60.01

Factory 245 45 17 431.80 110.25 652.30 2049.26 1609344 785.33 96560640 60.08 1001.28 30038.30 59.92

Factory 225 55 16 406.40 123.75 653.90 2054.29 1609344 783.41 96560640 59.93 998.83 29964.80 60.07

Factory Averages for Dodge Stealth & Mitsubishi 3000GT 653.13 784.33 Assumption: Average is used as the constant for variance calculations

Below are alternative sizes for tire/wheel combinations.
245 50 16 406.40 122.50 651.40 2046.43 1609344 786.41 96560640 60.16 1002.66 30079.80 59.84

255 35 18 457.20 89.25 635.70 1997.11 1609344 805.84 96560640 61.65 1027.42 30822.68 58.35

265 35 18 457.20 92.75 642.70 2019.10 1609344 797.06 96560640 60.97 1016.23 30486.98 59.03

275 35 18 457.20 96.25 649.70 2041.09 1609344 788.47 96560640 60.32 1005.28 30158.50 59.68

245 40 17 431.80 98.00 627.80 1972.29 1609344 815.98 96560640 62.42 1040.35 31210.55 57.58

Variable/Column Definitions and Calculations:
Width: The width in millimeters of the tire. The 3-digit first number used in standard tire sizing (i.e. 245/40/18")

Profile %: The profile height of the tire, as a percentage of the tire's width. The 2-digit second number used in standard tire sizing (245/40/18").

Wheel: The size wheel the tire fits, in inches. The 2-digit third number used in standard tire sizing (I.e., 245/40/18")

Wheel (mm): Converts the default inch measurement to millimeters (wheel x 25.4 mm per inch).

Profile: Converts the Profile percentage to millimeters based on the tire's width (width x profile/100).

Total Tire Height: A calculation of the overall height of the tire in millimeters. (wheel height x (profile x 2) ). Note profile must be used twise as the tire has a top and a bottom…

External Circumference: The distance around the tire's tread, distance traveled in one revolution of the tire, im millimeters. (2 x PI x (Total Height / 2) ).

Constant Mile: Calculation of number of millimeters in a mile. (5280feet x 12inches/feet x 25.4mm/inch).

Revolutions per Mile: Number of revolutions the tire must make to cover a single mile. (Mile / Ext Circ).

Constant 60 Miles: Calculation of number of millimeters in 60 miles. (Mile x 60).

Odometer Travel @ 60 Miles: The miles you odometer records if you drive a fixed distance of 60 miles. Smaller tires (shorter calculated Height) will cause the odometer to advance at a higher rate than normal. The closer to 60.00 the figure is for a tire size, the closer to the factory sizing is the tire, and the more accuare will be the odometer/speedometer. =((+L16/($K$11*60))/I16)*60 [ ( [Constant60Miles / (AvgRevPerMile * 60) ] / Constant60Miles ) * 60 ]

Variance at 1000 Miles: This shows that the variance your odometer will read over 1000 actual miles traveled. ((1000/60)*OdomTrav@60Miles)

Variance at 30k Miles: This shows the longterm variance over 30k miles. I chose 30k as an expected "life of tire", or an estimate of how long that set would be on your car. ((30000/60)*OdomTrav@60Miles)

Speed Variance @ 60mph: Shows the variance your actual speed reflects versus what your speedometer displays: If your speedometer reads a constant 60mph, your car is physically moving at the calculated rate shown. Note that smaller tires (Total Height) yield lower speeds per a speedometer reading of 60mph (or a fixed speed yields a higher speedometer reading). This is due to the fact that speedometers are calculated based on revolutions at the flywheel/axel, not at the wheel/tire, and is based on a fixed ratio based on a previously determined (factory) tire size.

Ummm...wow first off. So i sorta have to know what all the specs are on the wheel huh...you just cant tell me what i should get?

In general, take the width of rim divided by 2 then subtract the measurement of hub surface to outer lip width-wise to get your offset. Heres a site to give you some ideas as to the numbers http://toy4two.home.mindspring.com/offset.html and the stock offset is 46mm

As a side note, its better for the VR4 to have identicle rims and tires all the way around being that the car is AWD.