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Author Topic:   plus sizing tires
posted June 19, 2002 02:15 PM           Edit/Delete Message Reply w/Quote
I own a 1980 Datsun 280ZX
the original wheels are 5.5-6x14, the original tires 195/70-14 ToyoZ, I found 7x17 Revolution RZX Wheels made for this car, what size tire will fit the wheel and the Datsun, I think a 215/45-17 is closest to the diameter of the original tire size, is the extra width of the 17" tire going to clear everything in the wheel well.

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posted June 19, 2002 07:25 PM           Edit/Delete Message Reply w/Quote
you were right on as far as closest size:195/70-14 5.4 in 12.4 in 24.7 in 77.7 in 815 / mile 0.0%
215/45-17 3.8 in 12.3 in 24.6 in 77.3 in 819 / mile -0.5%
The final number shows that the difference is only .5% for the two tire sizes you mentioned. As far as the width not causing any rubbing on sharp turns, I would say you will need to consult this sites expertise on Z cars:

Here's some info on fitting non-stockwheel sizes on your Z:

.....Also, 225x50-16 tires on 16x7" 0-offset wheels will fit an early (lowered) model Z with only slight trimming of the rear fender lip. 225X50 15 tires on 15x7 0-offset wheels also fit with no trimming. (been there, raced on both) 205x60-15 tires are a good size for the 15" turbo rims and won't change your speedo 215x60- 15 also fit ok and have only a minor affect on the speedo. 225x50-15 tires WILL fit the 15" turbo rims with just a little bit of pooch.

First a little background. The TRA (Tire and Rim Association) set a 'design' or 'measuring' rim for each tire size, to ensure that all manufactures measure their tire on the same wheel. For 50 series tires and higher, the measuring rim width is 70% of the tire's section width, rounded to the nearest 1/2". For tires lower than a 50 series, the measuring rim is 85% of the tires section width. The actual dimensions of a tire are dependent upon the rim on which it is mounted.

Important note: A tire's width changes about .2" for every 1/2" change in rim width (over or under the 'design' rim). So you can 'stretch' a tire's width with an increase in rim width, within the approved range. Now for popular tire sizes from the fitment guide:

Tire Size Rim Width Range Overall Diameter Tread Width

185/70/14 BFG Radial T/A 5.0"- 6.5" 24.2" 5.5"
195/70/14 BFG Radial T/A 5.0 - 7.0 24.7 5.8
205/70/14 BFG Radial T/A 5.5-7.5 25.2 6.1
185/60/14 BFG Comp T/A HR4 5.0-6.5 22.8 5.8
195/60/14 BFG Comp T/A HR4 5.0- 7.0 23.2 6.2
215/60/14 BFG Comp T/A HR4 6.0 - 7.5 24.2 6.8
225/60/14 BFG Comp T/A HR4 6.0 - 8.0 24.7 7.0
205/60/15 BFG Comp T/A HR4 6.0- 7.5 24.7 6.1
215/60/15 BFG Comp T/A HR4 6.0- 7.5 25.2 6.8
205/50/15 BFG Comp T/A ZR 5.5-7.5 23.1 6.2
225/50/15 BFG Comp T/A ZR 6.0- 8.0 23 9 6.8
225/50/16 BFG Comp T/A ZR 6.0- 8.0 24.8 6.8
245/50/16 BFG Comp T/A ZR 7.0 - 9.5 25.7 7.5

This fitment info is obviously taken from my BFG manual (I had to become a TEAM T/A member to buy my Comp T/A R1 Road Racing Tires). Other brands of tires may have a slightly different range (so consult your supplier), but these will be pretty close for most. Oh, "tread width" is the actual rubber on the road -- section width (the first number in a tire size, in millimeters) is the widest part of the tire, which is most often the bulge in the middle of the tire. Section width is as stated, but tread width can change significantly from manufacturer to manufacturer.

In my 'archives' I found one other warning; "Never mount a tire on a rim width that is not approved." ". . .wheels narrower or wider than approved> will stress the tire sufficiently to cause poor service, and may even cause the tire to fail."

This information comes from:
http://www.car.lt/auto/cars.php?AutoID=5691 under the section on technical-wheel/tire combinations. I hope this helped you out.

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posted June 19, 2002 07:27 PM           Edit/Delete Message Reply w/Quote
Also, go to


for a lot of great info. on your car.

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posted June 19, 2002 07:32 PM           Edit/Delete Message Reply w/Quote
searching zcar.com, I found a similar question to yours. 17x7 Rims- Suspension Mods Necessary?
Author: WillieBoy240Z (---.transedge.com)
Date: May 16, 8:27am

I have a stock 240z with 14 inch wheels. I am planning on upgrading to some Enki 17" rims with 225/45ZR17 tires. I'll get spacers from somewhere, perhaps MSA if and when they begin selling them.

I am planning to replace stuts, springs and bushings. Doubtful I would go for coilovers unless absolutely necessary.

Also will be doing Toyota 4x4 front brake upgrade and maybe rear disc conversion.

The car will not be raced or anything. Just want it to perform respectfully and look good.

Will these wheels work with typical 1 - 2 inch lowering springs and non-adjustable shocks?

Reply To This Message Newer Topic | Older Topic

Topics Author Date
17x7 Rims- Suspension Mods Necessary?
WillieBoy240Z May 16, 8:27am
Re: 17x7 Rims- Suspension Mods Necessary? new
Sean73 May 16, 9:20am
Re: 17x7 Rims- Suspension Mods Necessary? new
WillieBoy240Z May 16, 9:32am
Re: 17x7 Rims- Suspension Mods Necessary? new
Sean73 May 16, 9:47am
Re: 17x7 Rims- Suspension Mods Necessary? new
WillieBoy240Z May 16, 9:52am
o rubbing wit Panasports new
nxmcbride May 16, 6:43pm
Re: 17x7 Rims- Suspension Mods Necessary? new
TM240Z May 16, 11:21am
Re: 17x7 Rims- Suspension Mods Necessary? new
abmartin May 16, 4:16pm
sure they'll fit, just place the wheel in the righ
rossc May 19, 12:58am

Of all the replies posted, all said that 17 X 7 rims will fit and that some have even gone with 17 X 8 rims with stock suspension in place.

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