We seem to get a lot of questions about wheel and tire combinations for our cars, So I thought I would try and address some of these questions, and help some people, mainly those that have no knowledge what so ever about cars (this is mainly for the 2G Eclipse).

What wheels should I get? What tires should I get? How big can I go? What’s a good size?

All of these questions, we have seen. So, I will start out be addressing some of those questions, by starting with the most basic thing, the tire.

The first thing that many people look at, is the tire tread.
The tread can come in various tread shapes, and designs, but all of them have a few basic things in common, no matter what the brand, size, or tread design.

Tires have basic classifications such as: All Terrain (A/T), Mud Terrain (M/T), All Season (Generally referred to as: A/S), High Performance (HP), and Ultra High Performance (UHP).

All Terrain: These tires usually have a large/prominent lug, designed for maximum traction on regular roads, AS WELL as on dirt. This is a tire normally only used on trucks, SUV’s, and such vehicles.
Mud Terrain: This tire has a very large and prominent lug designed for maximum traction in an off-road environment.

All Season: This type of tire, is the most normally seen tire on vehicles, with small to medium sized lugs. It is designed to give a good amount of traction on many surfaces. One the side of these tires you will see: M+S. This means that the tire is approved by the DOT for use in Mud and Snow. This is the best all around, general use tire.

High Performance: These tires come a few different tread patterns, some for a more all season use, but mostly with a directional tread. These tires are always accompanied by a higher tread ware, and speed rating for the tire. These are generally recommended for use on sports cars, and sport sedans.

Ultra High Performance: These tires are ALWAYS a directional tire, and ARE NOT rated for M+S. These tires have a very high, to highest tread ware and speed ratings ranging from 150-250+ miles per hour. These tires can only be used on road.

Tire sizes, that is always another question.
Tire sizes can vary, from car to car. To help you understand how tire sizes work, let’s look at the numbers that are on a tire.
These are the numbers that we are looking at, when it comes to a tire size: 235/40ZR17.

Z = Rim Diameter (in this case: 17)
Y= Aspect Ratio/Profile (In this case: 40)
X= Width (In this case: 235)

The only number that has ANY relation to an actual measurement is the rim diameter, that being, inches.

The: ZR reference is usually used to denote that a tire is a high performance radial. The “R” in this case stands for “Radial”. It may also just say "R".

Next, there is a Directional tread, and NON-Directional tread. Directional tires mean that the tire has been designed to used, with the rotation being point towards the front (or towards the direction that the car will be traveling) of the car. The tread pattern is designed to function at its maximum potential, when used in this manner.
A NON-Directional tire, looks more or less like a regular, normal tire, and it doesn’t matter how they are mounted.

“Well, thanks dude. But that doesn’t tell me what kind of tire I should get”

Guess what……. Nobody can REALLY tell you, what kind of tire you SHOULD get. It really depends on your application for the tire.

As an example: I personally use a 215/50ZR17 HP tire. This is a directional tire, that has great traction in normal, and normal wet conditions. Snow and ice though? HELL NO. Traction would be minimal, at the best. Because of this, I have a set of all season tires (205/55R16), mounted on regular steel wheels, that are used during the winter months.

Not everybody seems to think about this kind of thing, or hey, maybe you have another car you use during the winter. Either way, this is something that should be considered, for safety sake.

So, let’s think about the application, what kind of things are you going to be using your car for? Racing? High Performance Street? Daily driving? Street use, with weekend racing? Do you just want looks? What are you going to be doing?
I ask these questions, because I am poor, and I don’t waste money. In our current economy, we should make every cent count.

Any racing application SHOULD require a UHP, or at the very least, an HP tire.
HP street and street, any tire from an all season up to a UHP tire.

The high performance tire I bought, was about $60 a piece. Not bad. I mean yeah, I could spend $250 a piece for some UHP tires from Michelin, BFG, Nitto, Toyo, or some other company, but I am not going to be going over 120mph. I don’t need something that expensive. So, think about your application, factor in your cost, and go from there. If price isn’t an issue, then I guess none of that matters, but, for most people, it matters.
Here is a link, for various speed ratings: http://www.dunloptires.com/care/speedRatings.html

My tires are a “W” speed rated tire. Obviously, with a non-modified 95 Eclipse GS, I am NOT going to be going above 168mph. But, I get great traction, a good tread ware rating, and my tires didn’t cost an-arm-and-a-leg.

“Well, I guess that helps a bit, but, what size tire should I be looking at? Bigger the better, right”

That sort of thing is a very common misconception when it comes to tires.
Just because a tire is larger in every aspect, does not mean that it is a better tire for your car.
The actual amount of traction you have with an average tire, is no bigger than a regular sized 11X8 ½ piece of paper. Divided between all of your tires. THAT, is how much total tire aspect, actually touches the ground.
Now, take into account, your wheel size. With our cars, with can plus size our tires up to a 19” wheel. Would I actually do that? HELL NO. That is a LOT of metal, AND, a LOT of tire to move. If somebody takes one of our cars, and puts a set of 245/30ZR19 tires on it, and takes an IDENTICAL car, and puts 225/40ZR17 tires on it, which on is actually going to perform better?

To answer that question take this into account: Bigger tires and wheels = more weight to move.

That’s right. Tires and wheels that are stupidly big, are going to put more of a strain on your engine, your transmission, and your axels. Your acceleration will decrease, and your fuel economy will go straight down the toilet. Not to mention, the increase in cost for the tires and wheels, go up a lot, when purchasing tires and wheels that big. It really doesn’t look very good either. The absolute largest that I would put on our cars, is an 18” wheel, and that is pushing it. The ideal size, in my honest opinion is a 17” wheel.

The aspect ratio/profile of the wheel is really up to you. Something that needs to keep in mind is this: the lower the profile, the rougher the ride.
A low profile tire is going to give you a much rougher ride, than a higher profile tire. The profile/sidewall, is actually part of the suspension.
If you don’t care about the ride of your car that much, then the sidewall profile will not matter.
Something to keep in mind, if you are looking for performance, is that the higher the sidewall profile is, the larger chance there is for what I call “sidewall roll”.
In high speed turns, if the sidewall is too high, this can cause the sidewall to not be able to hold it’s form, resulting in the sidewall “rolling over”, and pulling the tire bead away from wheel lip, causing the tire to fail.

Lowering a car with springs, and adding in a low profile tire, will result in a rough ride. Period, no discussion. Sorry but, you can’t fight physics.
Once again, it all comes down to, you guessed it………… application. What are you going to do with your car?

I find that the majority of people with our cars, even turbo models, seem to like to go for ABOUT a 235/40ZR17 tire. This provides excellent traction, a low but not too low profile, is not overkill on the size/weight, and the cost is not crazy.

“Ok, I get it. But what about the wheels? What should I get?”

Wheels……………….. Where to start. How about this, lets NOT.
Wheels mainly are going to come down to aesthetic appeal. We are not talking about serious race application here. If we were, then you wouldn’t be reading this, because you would already know all of this, plus WAY more.

The one thing I have to say about wheels is this. No wider than 8.5 MAXIMUM, and that is pushing it BIG time. You might still rub, even with that. At 9, you WILL rub, 9.5, you will shave your tires. This is all ASSUMING, that you are not modifying your wheel wells on your car. If you are, then once again, why are you reading this? You probably already know all of this and more.

Wheels are all about what YOU like. Not about what others like. Be an individual, and use your head, for what YOU want to put on the car. The only question you should be asking about wheels really is, “Is this a good price for this wheel?”

When it comes to price, the general rule is: Shinny = Big price
Anything with chrome is going to run more than with gun-metal, or black (black being the cheapest).

Finishes vary from wheel to wheel. Chose what you like, and go from there.
If you want to know what a specific wheel is going to look like on your car, I find this site is a lot of fun, and a great help: http://www.wheelenvizio.com/
This little program is a lot of fun.

“Well, what about brands, for both tires AND wheels?”

I work for the nation’s largest tire distributor, American Tire Distributors (NO. I WILL NOT GET YOU TIRES,WHEELS, OR ANYTHING ELSE, SO PLEASE DON’T ASK!)
I know a FEW things about tires, wheels, and their brands.

Brands of tires and wheels, are really a question of how much money you want to spend, and your personal preference. For instance, I would rather use a set of Nitto tires on my car, than a set of BFG or Michelins. This is MY preference. Yours may be different. Some people would take a set of Firestone’s over a set of Goodyear’s, or a set of BFG’s over a set of Toyo’s. It all has to do with your preference for that specific brand, and the price you can get for that particular tire.
Note: I use Riken Raptors. This is a BFG product. With that as an example, there are many other brands that are made by many other major companies. Cooper Tires, makes A LOT of different branded tires, they are the “tire whores” of the tire world, and will make anything. Goodyear, Bridgestone/Firestone, Michelin, and other companies make other brands of tires under contract from those companies, and those tires, are made to the same standards as the manufactures standards. Example: Fuzion tires are made by Firestone, and JUST AS GOOD as any Firestone for the same application, it just costs less. It’s like aftermarket parts, just as good, but without the name brand cost. Keep in mind that this is my honest opinion, and in no way applies to all generic/aftermarket products.

IN CLOSING
I hope this info has helped all of you prospective tire/wheel buyers.
Everybody here at Mitsubishi-Forums.com is happy to help in any way we that can, hell, it’s why we are here. We don’t get paid to answer questions here, to help people, so we can’t answer all questions as quickly as you, or we, would like. So by writing this, I am hoping that it will be able to help, or at least answer the majority of the wheel/tire questions that people might have. If there is something you would like to ask, that is not detailed here, PLEASE, ask us, and we will all be willing to help, to the best of our ability.
Remember, this is nothing but a basic guide.
You want advanced stuff, well, the internet is a GREAT thing. Lots of info there.
Have fun, and be safe.
:beer:

jesus christ you almost put me to sleep... where do you find the time for this???

very good though oh and not all tires will says zr for size a lot just say r... yaya

Thanks. I do hope this helps people out a bit when it comes to the basics.
Thanks for pointing out the "R" and "ZR". I corrected that.
There is also a "D", however you will usually see that with an "ST in the beginning, such as: ST215/75D15
This is usually associated with a tire used for towing applications, and defines whether the towing tire is a bias, or non-bias tire. The "ST" is only used in towing applications and doesn't apply for this particular instance.

they should pin this one, good job :clap:

Very nice :clap:

Hurray for normal member stickies! :D

Normal? Not sure about.
I don't think the Doc was saying that, it ws a litlle hard to tell, with all the gurgling, and he kept grasping at my hands around his throat for some reason....... :)

lol i meant normal members as in not moderators lol

I will never understand why people put Z rated tires on a car that wont go over 140mph.

3gs+ are the only ones that wont break 140mph :wacko:

And 1.8's :P

1g, 2g, 3g, 4g.... none of them will ever break 140 and sustain it for long enough to need those tires. It's idiotic.

bravo calin kudos. exellent write up. even though i had to load it on my phone 4x to get the full thread. lol but im reporting the problems on the problems thread so maybe they will get fixed. i hope so. i use to know a formula for the weight of the tire+rim to the hp/torpue ratio to get the perfect median for performance but i cant find it for the life of me. if anyone runs across it please post or send it to me. thanx

"Unsprung weight and rotational inertia, as we know, is more important than sprung weight. The general rule of thumb says that 1 pound rotational or unsprung weight is approx equal to 10 pounds static weight."

"Another rule of thumb is that every six
pounds of weight reduction is like adding an additional horsepower. "
"3.7 lbs savings
x 10 static rule of thumb
x 4 wheels
x 6 horsepower rule of thumb
--------
about 24 horspower gain"

er... 3.7 * 10 * 4 * 6 <> 24... it = 888. >.> lol I am confused.

EDIT: Ah ok, rereading the info there is a typo on the example.

it should be (3.7 * 10)/6 *4 = 24.7

(Note: You cna do the caclculations in any order, I just wrote it that way because rule of thumb si to follow the order of operations)

I didn't write that equation. But one thing will have to be changed for it to be applied to our cars.
It's like one of those critical thinking questions from highschool math class. You have to know how to look at it. But the rotational inertia formula only applies to the tires receiving drive. Newtons 1st law of motion says, in a nutshell, that whatever moving state an object (tire) is in, it will tend to remain in that state untill a force is acted upon it. In reguards to automobiles,the external force will inherently be the engine, acting only on the tires it drives, along with other rotating components such as the axles, flywheel, ect. (But for now were just focusing on the tires, and rims). Therefore the lighter the object, the less force is needed to cause it to move. In other words your engine dosen't have to work as hard to make the tires spin, in which case the leftover horsepower can then be utilized to overcome other forms of resistance a vehicle creates.(Wind drag, gravity, ect.)
My argument is thas as the formula for rotational inertia (case in point) and "dead" weight are very different, it is plain to see that the rear (trailing) tires'/rims' weight reduction will yield a much less significant advantage with respect to minimizing resistance. So unless the vehicle is awd (which our cars are not) the formula should read as follows
( 3.7 lbs savings
x 10 static rule of thumb )
x 2 wheels driven
x 6 horsepower rule of thumb
------------------------------------------
12.3 horspower gain on 2wd models

I should have caught it before I posted it before. SRY (IMG:style_emoticons/default/auto.gif)

LMAO good call, I didnt even catch that, myself.

Also, just a little bit of knowledge being passed down, but if you are wondering how the speed sensor on a car works:

The programming of a speed sensor is actually very simple and strait forward. a constant is declared in the script which is the wheel diameter. For this example we will use 17" (Remember, you have to include the tire too, but for simplicities sake, we will ignore the tire). the sensor then divides the diameter by 2 resulting in the radius. (8.5"). Since the circumference of a circle = the distance traveled in 1 rotation, we can find use the following formula to find this:

C= 2 * (pi) * r

Where C = the circumfrence and r = the radius

So we have:

C = 2 * (pi) * 8.5

Thus,

C = 53.38"

After that calculation is performed, the sensor counts the number of rotations per second. This various with horespower, wind conditions, elevation, etc.. etc.. For our example we will use 3 rotations per second (Yea, I pulled that number out of my ass... lol) After the rotations are counted the sensor multiplies that number by the circumfrence and stores the result in inches per second, like so:

speed = 53.38 * 3

Thus,

speed = 160.14 in/s

After all this is done, the sensor simply converts this data to the appropriate units. (MPH for the US, and KmPH for everywhere else.)

Speed = 9.09 mph

So in conclusion, a 17" wheel (wihtout the tire lol) rotating 3 times per second is, in fact, traveling 9.09 mph. Seem slow right? Well think of high small that wheel is if you include the tire. :x

You can substitute the radius variable circumfrence formula, with the diameter variable and skip two steps.

Ex. 53.38=2*3.14*8.5 = 53.38=17*3.14

If you really want to get technical, a loaded tire is an ellipse, not a circle. So you will have to find the elliptic integral and write out about a page and a half of equations converting expansions. And after that decide which of the two approximations you are most confortable with. (depending on how good at COS you are). And after all that it's still not accurate because turning, hills, wind (creating downforce), will change the elliptic integral of specific tires hundreds of times a second. (IMG:style_emoticons/default/wacko.gif)

It is cool to see the way putting a larger or smaller tire on a car can confuse the hell out of a speed sensor. And that only couple of inches on a tire can make a huge difference in percieved MPH. (Im leaving out the tires too) (IMG:style_emoticons/default/tongue.gif)

Ex. 16in. rim (on my car now) * 3.14 (pie) has a circumfrence of approximately 50.24in.
So if the sensor reads my tire is spinning 15 times a second it would calculate 15*50.24=753.6in./sec.

And convert it (5,280ft in a mile = 63,360 in. in a mile) (60 secs. in a minuite)
So it would take me 84.07 seconds to travel a mile based on 63,360 (inches in a mile) / (753.6 / 12)
Totaling 62.8 ft/sec
And since 1ft/sec=.68 mph the formula 62.8*.68=42.7mph at 15 RPS(Revolutions per second)

But lets say I put a 12in. rim on the car
Following the same thing I did above the MPH will be reduced to 34.69mph at 15 RPS(Revolutions per second)

This difference increases with speed
Lets say my sensor is reading 25RPS with a 16 in. rim
It will register 71.17 mph
On a 15 in. 66.72MPH
On a 14 in. 62.27MPH
On a 13 in. 57.82MPH
And on a 12in.
It will register 53.38mph
NOW THATS A DIFFERENCE

Yea it is pretty interesting, but does the sensor view the tire as an ellipse or a circle?

Circle.