Thinking About Tires... Question On Tire Height.

[ratio411]

"Normal" tire height for our cars are 25" to 26" tall, regardless of rim diameter. (25.7" to be exact)

Has anyone tried to run 26" to 27" tall tires all the way around? Again, regardless of rim diameter?
(If so, pics?)

The reason I ask is that my GT currently has stock 16" Ponies with 26.7" tall tires... 1" taller than 'normal'. I bought the car this way, and at first thought the car was lowered because the tires filled the wheelwells so good. Then I checked the tire size.

Anyway, what I am getting at is the idea that one could run a 16", 17", or 18" rim with tires that are only 1" taller than the norm, and the car will take on the appearance of being lowered. Mainly the GT though, because of the ground effects. This same idea may not hold true for an LX.

Has anyone done this with 17" or 18" rims?
What would the drawbacks be?
The biggest pro I can think of is not having to actually lower the car and deal with ground clearance issues, or even issues when working on the car, like getting a jack under it.

 

[NIKwoaC]

Con: reduced fender clearance, reduced effective gear ratio, increased rorational mass
Pro: better ride quality

 

[ratio411]

The only thing you said that made my skin crawl was "increased rotational mass".
The rest is fine.
The gear ratio can be compensated with ease.
The fender clearance is going to be a problem with regular diameter tires, because I would lower the car anyway to fill up the wheel wells. Then once it's lowered, you have the cons of ground clearance and getting a jack under the car without worrying over the ground effects.

 

[ratio411]

I am hoping someone has tried this with 17 or 18s and has pics.

I want 17" Saleen SCs, (would love 18s, but no one makes them) and if this is truly a good idea, I have some 26+ inch tires picked out for 17" rims.

 

[RedWings44]

The only issue I can think of is wheel well clearance...especially when hitting bumps. I'm not an expert though. Not really a person to lower vehicles.

 

[ratio411]

The only issue I can think of is wheel well clearance...especially when hitting bumps. I'm not an expert though. Not really a person to lower vehicles.

Yeah, I don't have a problem lowering the car, but I know from experience that it leads to all sorts of clearance issues.

I just thought that filling up the wheel wells with larger tires would give it the appearance of being lowered, without actually doing it.
Like I said, the car has larger diameter tires on it right now, and it has the 'look' of being lowered because of it.
I was hoping that someone has already done this with larger diameter rims...

 

[RedWings44]

Yep. Like I said, I'm not an expert. You won't bottom out like if you lowered your vehicle, but you are still likely to hit your tires on the wheel wells over bumps and what not. I don't think it would give the desired effect, but a similar one. Also, whenever changing tire sizes, don't forget to have your speedometer re-calibrated

 

[ratio411]

I did a google on it, and found a few cars with 17/18 rims and larger diameter tires.
It's hard to tell from the pics though because the rims are not your run of the mill Stang rims like SC, FR500, Cobras, etc...
They are more 'rice' like rims. The tire height does give it appearance of being lower, but again, the rice rims all in one width don't really translate into a staggered setup with 275-295ish rear tires.

I have also found plenty of Draglites with extreme stagger and 27ish inch tall tires, and again, they look good, but not quite what I am trying to see.

I'm going to keep looking.
If money was no object, I'd just try it and see if I like it, but it doesn't quite work like that.

 

[RedWings44]

I know how that goes lol. But ya. With the exception of clearance, it would appear lower...but the width of the tires also takes away from the desired effect. Obviously its your car, but I am more partial to the stock look of most vehicles...unless its done in a nice way lol

 

[Gearbanger 101]

You'll get the "at first glance" appearance of being lowered, with none of the benefit. Aside from looks, people lower their cars to drop the center of gravity in order to improve handling.

Going with taller tires will actually have the opposite effect, by raising that center of gravity an extra half an inch and further reduce handling capabilities. Couple that with the fact that you've also added half an inch to the sidewall height increasing latteral flex and the issues is compounded.

Also, like Nik stated. A rotational mass increase and reduction in effective gear ratio are also a negative.

True, you could compensate by playing with rear end ratio a little..but you're still running taller, heavier tires. Still gonna consume horsepower and hurt mileage.

If it were my decision, I'd replace the tires and wheels with proper diameter ones. My guess, is that because only a few companies make the 225/55/16 tires that originally came on the pony wheels, the previous owner found the tires to be more expensive and only chose to replace them with 225/60/16's because they were a cheaper and more common tire size. Easier on the wallet, but not the best choice IMO.

 

[RedWings44]

Kinda what I was getting at. I've never seen a vehicle lowered for center of gravity purposes...although it makes sense...perhaps I just don't notice lol

 

[Gearbanger 101]

Kinda what I was getting at. I've never seen a vehicle lowered for center of gravity purposes...although it makes sense...perhaps I just don't notice lol

That's the primary reason vehicles designed for improved handling are lowered. The looks are secondary. Ever see a go-cart get around a track. You tush is about an inch off the ground.

 

[RedWings44]

Oh ya, go carts, NASCAR, racing, etc...I just meant on street vehicles. I have only ever seen (noticed) them lowered for the look. I prefer clearance to the ground...but I'm definitely not one to raise vehicles

 

[CarMichael Angelo]

Oh yea! I get to be the example.

Front tires are 225 x 50 x 17 and are 26" in diameter.
The rears are 275 x 50 x 17, and are almost 28" in diameter.

The benefits have already been touched on; better ride, less impact harshness.
The cons;? Alot more sidewall to move in a corner makes for a slower responding tire in the corners, as well as a sidewall that tends to contact the inner fender lip only after entering a hard right or left corner.

 

[RedWings44]

Ya, looks like it fills up the wheel wells too much...my opinion

 

[ratio411]

Oh yea! I get to be the example.

Front tires are 225 x 50 x 17 and are 26" in diameter.
The rears are 275 x 50 x 17, and are almost 28" in diameter.

The benefits have already been touched on; better ride, less impact harshness.
The cons;? Alot more sidewall to move in a corner makes for a slower responding tire in the corners, as well as a sidewall that tends to contact the inner fender lip only after entering a hard right or left corner.

Thanks Mike!
That's what I was looking for!

 

[CarMichael Angelo]

Ya, looks like it fills up the wheel wells too much...my opinion

Kinda like how my boot will fill your ass,....that kind of "too much"?

Just kidding.

P.S. are we Swedish? What's with the "Ya"?

Just kidding.



"Yeah" The way your rude teenager answers you. "Yea" Sounds like hay, except it doesn't grow in a field, and Ya is how Heide affirms you want another smoked kipper.


Just kidding.

 

[NIKwoaC]

I always thought "yeah" and "yea" were pronounced the same, and "yay" was what shounded like "hay".

 

[ratio411]

You'll get the "at first glance" appearance of being lowered, with none of the benefit. Aside from looks, people lower their cars to drop the center of gravity in order to improve handling.

Going with taller tires will actually have the opposite effect, by raising that center of gravity an extra half an inch and further reduce handling capabilities. Couple that with the fact that you've also added half an inch to the sidewall height increasing latteral flex and the issues is compounded.

Also, like Nik stated. A rotational mass increase and reduction in effective gear ratio are also a negative.

True, you could compensate by playing with rear end ratio a little..but you're still running taller, heavier tires. Still gonna consume horsepower and hurt mileage.

If it were my decision, I'd replace the tires and wheels with proper diameter ones. My guess, is that because only a few companies make the 225/55/16 tires that originally came on the pony wheels, the previous owner found the tires to be more expensive and only chose to replace them with 225/60/16's because they were a cheaper and more common tire size. Easier on the wallet, but not the best choice IMO.

I agree on all points.
I think you got it right all the way down to the PO's thought process in buying taller tires.

I probably won't do it, it was just a thought. However the 'cons' don't bother me so much because I am not building this car for any sort of track or extraordinary performance goals. I am just wanting a nice looking Stang with a warmed over 5.0 at this point.

As far as the gearing goes, I can swap a gear in an afternoon now that I have done a few.

 

[ratio411]

Speaking of gears, I have a 3.55 rear laying around, and I think I'll throw it in there today.

I have yet to drive the GT, it sat for 4 or more years, and the fuel pump seized.
I dropped the tank, and sure enough, the pump seized and the sender doesn't work anymore.
We proceeded to clean out the fuel tank, which was not in bad shape at all, but the metal baffle that surrounds the pump pickup came loose and was just sliding around in the tank. So I bought a whole new fuel system.

I have the 3.55 rear laying in a corner, so while the tank is out, I will probably throw it in there before putting the new tank up.

The new setup cost me just under 300 bux.
I got a new Spectra tank, Spectra fuel level sender, Airtex replacement pump on a new hanger, and a fuel filter.
I put it all together with new grommets and everything. Just gotta get out there and do the rest now.

My son volunteered me to put some 13" brakes on the front of his 94 GT today... So maybe I'll get a chance to work on my car.

Tommorrow, my other son has me working on his 81 Fox Fairmont...

A father's job is never done.