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Discussion Starter · #1 ·
I got a pair of 15x7 American Racing Chrome rims, and I know im putting GoodYear Assurance TripleTred, but I need to figure out a good rubber size. Someone please help.

I want the tires to take up a little more of the wheel well without going too big. I would like them to be somewhat low-profile, but not extreme. The width doesn't really matter, so whatever is a standard size for 7" wide will be fine. Thanks in advance!

Jon
 

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If your goal is to have more tire take up more of the wheel well, I think you are going to have a rough time by just buying biger tires. IMO to the point where it will look kinda stupid. Instead of getting the tire to fill up the well, why not make the well smaller? Lower it with the midway spring from OGTS. With the miway spring you wont have to buy the rear springs and you can get a decent tire and a decent price.

Probably look at a 195 or 205/60 15 I dont think the wheel is wide enough for a 50 series and besides, with the 60 series youll have a taller sidewall to fill in the well.
 

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Discussion Starter · #4 ·
Ok, well lets figure different then. Lets say eventually I will lower the car like an inch or 2, but for right now I just want the OVERALL TIRE SIZE a tad bigger then stock. What would my final tire dimensions be and how much of a low-profile would I be looking at? Would I go with like the 195 or 205 or bigger or smaller? Also, what does the 60 mean and should I go with a larger or smaller number with that? Thanks alot!

Jon Samuel
 

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boomerang opeler
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jon did you try that site
its real easy just put the size of stock tire in (mine was 165 /70/13 )and the tire uses that as a base line then play with width /profile (the 60 you asked about [60%side wall to tread width so a 205 50 15 would have a width of 205mm a centre that is 15" diameter and the side walls would be 50% of width or 100mm]/wheel size) and you will work out the right tire size and profile for what you want

and it will tell you things like what diff bigger tires will do to your speedo

got to work those fingers a little or you wont learn :D

ps the circle you get is the orig size so you can see if the new tire is bigger diamiter or smaller
 

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Things like tire sizes are easily explained on numerous sites on the internet you will just have to play with some tire dimensions. The "60" would mean that it's a "60 series" tire and that is the side wall height ratio in proportion with the tire width so a 205/60 would have a 4.84" sidewall. Also 1 or 2 inches of lowering isn't small amount, that will drastically narrow the posibilitys of a prefered tire and also rim size and that should be taken into account when the rim width and diameter were decided and of course the actual width and sidewall height of the tire.
 

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ya beat me to it baz
 

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nice to see you again jordan hows you spud cannon :D

and jon to work out what size would fit a 2" drop you would need to fit a wheel on and use a trolly jack to lift the hub 2" higher than its normal point then measure and see how high you have left in mm then take off a little for wheel movement and then see how high the side walls can be
then work our the tire size that will clear it
 

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jordan said:
Also 1 or 2 inches of lowering isn't small amount, that will drastically narrow the posibilitys of a prefered tire and also rim size and that should be taken into account when the rim width and diameter were decided and of course the actuall width and sidewall height of the tire.
Not neccessarlily so.... I am getting the full sport suspension and lowering my car 2" in the front and I am looking at a 16 x 8 wheel with a 205/50 or 205/45 size tire.

The /50 /60 /70 in the tire size is this. Say you have a flat piece of rubber that is 10 inches wide and you take 2.5 inches off of each side and roll that up to make a side wall. 2.5 + 2.5 = 5 or 50% of the 10" piece of rubber. That's a /50 series tire. Take 3.5 inches off of each side... 3.5 + 3.5 = .70 or a 70 series tire. The higher the series, the taller the side wall, ergo the taller the tire.

All Im saying is that I've seen people put 17 or 18 inch wheels with a super low profile tire in an attempt to fill up the wheel well without lowering the car and it looks, well... IMHO stupid. It looks like it NEEDS to be lowered.

The car in my avataris the look I am trying to duplicate, except with a little different style wheel. It has 15 x 8 with a +12 offset wheels on the frontwith 205/50 15s On the rear it has 15 x9 +3 offset with 225/50 15's rear

Its been lowered 2" in the front and 1" in the rear. LOOKS AWESOME!!! Agressive mean European stance. Kick Butt!!!!
 

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Thom I must admit you had me confused with your explanation of tire sizing.

To simplify the equation the aspect ratio, the 50, 60 70 etc, is the side wall height based on the cross section at it's widest point. The widest point of the tire is normally the sidewall bulge.

To clear up a common misconception just because a tire has a smaller aspect ratio does not necessarily mean it is smaller in diameter then a larger aspect ratio tire.

Here is an example.
A 225/6015 tire has a cross section of 225 millimeters side wall to side wall and a side wall height of 135mm (225 x 60% or .6) and fits on a 15 inch rim.

A 185/7015 tire has a cross section of 185mm and a side wall height of 129.5mm (185 x 70% or .7)and also fits a 15 inch rim.

The 225/6015 tire has an approximate overall height of 651mm or 25.63 inches. The 185/7015 tire has an approximate overall height of 640mm or 25.20 inches.

Of course the 185/7015 will be narrower by 45mm.

hth
Brian
 

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Discussion Starter · #11 ·
Think I am going to go with the 205/60/15. How much of a low-profile do you think that is, and how close to stock would the overall be?
 

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Discussion Starter · #12 ·
Actually, after using Baz's website, I kind of like the look of a 50 instead of a 60. If I could get them in that, would anyone recommend it? Does anyone have pics of their tires with anywhere near close to these sizes?
 

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I think you might have a problem finding a 50 series tire to fit a 7" rim. They might require an 8" rim. But I dont know. Havent looked for one.

If you are not planning on lowering the car, Id go for the 60 series.
 

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Look under the members galleries for Dallas. He has Huge 16 x8 in the front and 17 x 8 in the rear.

Here is a large pic of my avatar. Click on it to enlarge it. Remember.... This car has been lowered 2" in the front and 1" in the back.
 

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I had a black 70 GT that had the GT source lowered front spring. I ran Nitto NT450 tires, sized 195/50/15s on 15"x7" ROH Synpers and it looked great (in my opinion at least). This size kept nearly the same rolling diameter so that the speedo wasn't too far off. They nicely filled the fender wells after it was lowered with the GT source spring, but there was enough sidewall that it didn't look stupid. I still have the wheels and tires, and currently run them on my 74 manta. I'd highly recommend that tire size. The 205s will work too, it's just a matter of personal preference. I like the aggressive stance that it gave the car. I'm partial to seeing some sidewall of the tire, and don't much care for anything over a 15" wheel on GTs. But again, it all comes down to personal preference. I now have a 69 GT with Lenk flares and airdam that will get the Snypers, and I have a set of American Racing Libre wheels that will hopefully get some white letter tires soon for the manta. JD Wheels has a picture of my black GT with the Snypers and the 195/50/15 tires on their website, under the ROH Snyper section. Hopefully this will give you an idea of what to expect:
http://www.jdwheels.com/images/Opel GT Snyper.jpg

Todd K.
 

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Todd, was that picture BEFORE you lowered it? Or, did you get the Mid spring to lower it only 1 inch? I am assumming you did not lower the rear?
 

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Thom71GT said:
Not neccessarlily so.... I am getting the full sport suspension and lowering my car 2" in the front and I am looking at a 16 x 8 wheel with a 205/50 or 205/45 size tire.
quick question
what are you lowering the rear as with these sizes you will have a rear that is 1" over stock height and 1" under at the front
and i know that they do not like that much of an imbalance
i always wonder why folks go to the expense of lowering a car then put wheels on it that put it back to the same hight or there about
better in my opinion to stay with something smaller and lighter (as big wheels have big heavy tires on them) so that you get the benifit of the springs and dampers
 

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The look. I want a very specific look. Also, from everyone that I've talked to that has done this, they say the car handles GREAT!!!

Also, I've got the suspension in the back that lowers the back an inch as well. I just need to install it.
 

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That was with Gil's sport spring. I had planned to lower the rear, but sold the car. Wonder if anyone on the list has it now? I sold it when I lived in Lithia Springs, GA. Black 69 GT, getrag, ran and drove great!
 

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Sparky73 said:
Actually, after using Baz's website, I kind of like the look of a 50 instead of a 60. If I could get them in that, would anyone recommend it? Does anyone have pics of their tires with anywhere near close to these sizes?
My Gt has 205 50 15 front and 245 50 15 rear mounted on 7 X 15 wheels you can see it in the photo gallery Most Popular 98 picnic. car is not lowered. Or for a fuller look but with a little bit of rub on the front you could go with 225 50 15 all the way around. Stock height. Check Texas Opel meet for last fall and spring of last year for pics with the 225 50 15 on the same rims.
rk
 
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