wheel size


Well-known member
what kind of affect does wheel size have on performance? the car is currently riding on 14x6's. i'm thinking about 16's with low profile rubber. how would this affect the car?
Two things that I can think of will affect the performance of the car. First is the overall weight of the wheel. Second would be the overal diameter of the wheel and tire together. Changing the overall diameter of the drive wheels is like changing your final drive gears. Weight can also slighty affect the performance obviously the lighter they are the less horsepower it takes to sping them. Check into Weld. They make some really nice wheels in lots of different sizes.
Another option is the American racing company. they have a good selection of different styles and a range of offsets for each wheel.

All of the above is correct.

One thing to consider though.

If you are running 14X6 with a stock tire, you can increase wheel size and go with lower profile tires and not change your gearing too much.
If you do that you will get a better tire with more road grip and a stiffer sidewall that will handle better in the turns and improve braking.

I am going up to a 15X7 wheel and using a comperable tire to have the same wheel diameter I have now only less rubber.

As for the wheels, if you have the 4.5/4.5 rotors or drums you will not find anything from American Racing anymore. They do not sell the correct BS for our application. You have to go with their Billet line which is expensive.

Summit racing has Weld wheel products and they carry a few options for the 4.5 wheel. As well Mustangs Plus carries the Vintage 48 which is a 16X8 wheel and not an option for me.

There are wheels out there, but you might spend a bit of time looking for them.

Good luck!
8) handling will improve with wider tires, but it will also degrade because of the added unsprung weight, how much depends on how much heavier the new wheel and tire combination is compared to what you have now. also braking performance will degrade slightly again because of the added weight of the new wheel/tire combo, but again it will also improve because of the wider rubber. overall you should see improvement in both area's.
When I did the original rear end and Granada brake swap I went from 195/75-14 tires on 14x5.5 rims to 205/65-15's on 15x7 rims. Tire diameter was the same. The effect was pretty dramatic. Handling and braking were a lot better and the way the car felt was pretty different too. More responsive and communicative.

Last week I switched from the 15's to 16x7.5 wheels with 225/50-16 tires. Another big jump in performance. If I get a chance, I'm going to try 245/40-17's to see what those are like.
Jimbo brought up a good point. The bolt pattern for the 6's (4 lug) is different spacing then the V8 5 lug. Selection is limited for the 4.5. Just something to consider. When they ordered my wheels they got the wrong bolt pattern and well long story short I went into the store about 5 times and came away without wheels until the 6th time when they finally got the right wheels and lug nuts for my Draglites.
I found that early Datsun Z cars had the same lug pattern as the wheels for the I6s. I found a set of 15x6 three piece aluminum wheels on Ebay with 195/60R15 Falken tires on them. Bolted right up after installing an offset adaptor. I'd suggest doing an Ebay search for "Datsun wheels" and keep looking until you find something you like. Just make sure you confirm the spacing and the offset before you buy!
As important as the bolt pattern is the back spacing. Typical Stang can't handle more than 4" until you get to 16" wheels and then no more than 4.5, and that will depend on the wheel. Datsun, MGB, 3 series BMW, etc. are good ones to look for. If you stick with wheels made for rear drive cars the fit will be better. I have a set of one piece BBS aluminum wheels the were origional equipment on early 80's BMW's (14x6.5). I have also seen them on 240Z's. I put 195x65 tires on them. Handle very well and the whole set is 4 lbs. per corner lighter than original equipment.

I just thought of another option for you....

One thing you can look for are dual drilled wheels for either 4.25/4.5..
They will have an extra set of lug holes, but you might be able to run without spacers. I never liked them.

Weld wheels has some nice Dual Drilled pattern wheels with the correct BS.... and you might find more import options this way.
Choosing wheels for my restoration was the single longest and most painful process for me, and I can share one piece of advice.

The only company who still makes new, reasonably priced (note that is bold) wheels with the correct 4x4.5 lug pattern and 4in back spacing is Eagle wheels. You can see a good cross section of wheels at this site:


If you have a local America's tire company they can order them for you.

I have the 028 style on my Mustang page


I searched endlessly for wheels that would fit. I wanted 15in rims or larger so I could get good tires. And I mandated that I wouldn't use spacers which pretty much rules out any of the import wheels. Looking at e-bay auctions or junk yards is also an option but I wanted something new. There really isn't much out there.

Good luck on your search. Let me know if you find anything![/b]
i'm really starting to get frustrated with this. there just aren't that many out there. these are a few i'm considering:


summit has a good price on these, but 15" is the larges available size. i love the look of the wire covers so i'm considering wires. i'm just not quite sure about people's reaction, or the look. i'd have to see them on a car first.

most of the wheels i've found with the correct bold pattern i've found are for FWD only. If anyone has suggestions or pics, let me know.
Actually I like slotted mags, and the Datsun Z cars came with 14" aluminum mags like these....

There's always some for auction on eBay!