HybridZ FAQ

Section II: Wheels/Tires

Fitment
1: What wheels will fit my Z Car?
 

The ones that are on there now! Or perhaps you mean, how big can I go?
On an unflared car, the limiting factor is the rear. There's not much room in there between the fender lip and the spring.

Here are some combos that are known to work on the 240Z:

Diameter Width Backspacing Offset Coilovers Stock struts Tires Notes
17 9 162mm   Yes NO! 255/45 Rear perch mounted high, above tire, with short spring. Go here for more info.
17 8   20mm Yes No 235/45 Very good, but tight fit. Hard to find these.
15 7.5 4 7/8   Yes Yes    
14 8   0 Yes Yes 225/60 Tires rubbed fender lip. Rolling would've helped
               

Note: the standard Z Car bolt pattern 4 on 4.5 inch.

There's a very helpful tool provided by Rick Tolan here.

Please email me at faqwheels@jeromio.com if you have a fitment combination to add to this table.

Tire Sizing
2: I bought 245 sized tires but they rub. I thought 245 size tires fit a Z?
 

There are advertised tire sizes and actual tire sizes. The DOT has certain rules for stating the various dimensions of a tire and standard rim widths that must be used. But, in the real world, things are not what they seem.

For example:

Hoosier's Sports Car DOT Radial (the S03 series) in size 245/45-16 only has a "245" section width on the DOT specific standard rim width of 8". Hoosier's recommended rim width range is 8.5" to 9.5" with 9" being ideal (because of the 9.2" tread width.)

If you call Hoosier and talk with one of their product managers for this tire line (I talked with Jeff Speer) they do not recommend running this tire on an 8" rim. The actual tire size on the recommended 9" rim is 257/45-16.
3: How wide and tall are size 245/50-16 tires?
 

You can calculate the various dimensions of a tire using the formulas below. Keep in mind that each manufacturer varies a little bit from the "ideal" dimensions.

Tire size: 245/50 ZR 16

245 is the section width in millimeters (mm) 245mm/25.4 = 9.64inches.
50 is the aspectratio, meaning the height of the sidewall. It is expressed as a percentage of the width ie. 245mm x 50% = 122.5mm. in inches it comes to: 122.5 / 25.4 = 4.82"

16 is the diameter of the rim in inches.

Tireheight is sidewall plus sidewall plus rimdiameter: 4.82" + 4.82" + 16" = 25.64"

Z is the speedrating: 149+ mph

R means Radial construction (no R means bias ply construction)
One more example: 255/35 ZR 17
width 255mm / 25.4 = 10.04"

Height 255 x 35% = 89.25mm
Height in inches is 89.25 / 25.4 = 3.51"

Tireheight is 3.51" + 3.51" + 17" = 24.02"