Another tire/wheel question. It probably has been answered a hundred times but there are so many tire threads that searching through them
would take days.

So, to be concise. I want to put a boosted 3.8 Pontiac V6 in my 1985 Fiero. During the process I want to upgarde the stock wheels and tires also.

Wheels will be used ones because I can't just go out and spend a bunch of $$ on new wheels. I have a list of cars that have a 5x100 bolt circle so I will refer to that list.
As an addemdum to what I just said, Pontiac offered 5x100 wheels on several models that they produced including; Grand Am, Phoenix, Sunfire, Sunbird,
Tempest, Vibe, 2000, and 6000. Do any of these cars feature wide rims? You can see the complete list by going to: www.stocktonwheel.com

First question regarding wheel size. I am thinking of using 16" wheels because 17" wheels that fit will need a very low profile tire. And I do not
like the look of really low profile tires on this car. Will running 16" wheels buy me much in that regard? Is there still a large selection of 16" sport
tires on the market?

What is the preffered offset for wider tires front and rear? Since I am planning to use a 3.8 I want to put some wider tires on the rear especially.
Regarding this, the car will be a road car influenced car and not a drag car. Will running skinnier tires in the front and wider in the back mess up the balance of the car?
I am thinking it might make the car turn-in more rapidly. Would wheel spacers help correct this if put in the front? Usually road racer type sedans use
equal width tires on all 4 corners.

What are the limiting factors affecting wheel rub in the front and in the back? Will coil overs allow wider tires/wheels in the back? How about the front?

Thanks in advance for any and all well considered suggestions.

Randy

Just a couple of things. I am running 17" on an 86SE which is the same body as the 85GT. I do run 45 series wheels on stock offset, which I believe is 35mm. I use two different sizes because the ones on the front will scrub the strut spring boss when installed on the rear. I have no scrubbing problems due to turning, even though the car is apparently lowered. Lowering doesn't affect the relation of the wheel to the stock rear struts, so that's not what creates the clearance issue. There is less than 1/4 inch clearance. The smaller diameter front tires would let the sidewall scrub the spring boss.

Sixteen inch of the same offset would probably bring the sidewall down and closer to the spring boss. There is a wheel clearance chart someone produced. If I can find it, I'll edit it into this post.

Compliments of Joe Torma

https://images.fiero.nl/2012/wheeloffset.jpg

[This message has been edited by fierofool (edited 02-16-2024).]

I am running 16 x 7 (38 mm) wheels with 205 and 225/55 tires...Those tire sizes were used by several popular cars back in the 90s so a lot of options (I run General G-Max tires)

To give you an idea of what those size tires are compared to C8 vette....The Vette weighs 3700 lbs (approx') and my Fiero weighs 2600 which is a ratio of 1.42 to 1....so the front 205s equal 290 mm wide tires on the Vette, while the 225s equal 320 mm wide on the Vette.

I eliminated 6 lbs off each front wheel/tire and 3 lbs off each rear when I switched from the crappy 15 x 7 after-market wheels I had in the 90s...the car went from driving like a tractor to driving like a modern car....Lesson; keep your wheel/tire package LIGHT.....also, don't go crazy on size- either the GIGANTIC wheels or super-wide tires.

[This message has been edited by cvxjet (edited 02-16-2024).]