Question for the "big tires" people.....
#17
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I was a tad thrown off because my new front tires are a 225/40/18....and with the back tires being 285/30/18, I thought the front should also be in the "30" series....(as, from the side, the front look bigger than the back) but I suspect that the 225/40/18 is similar to the original size 16' tire size?
...and I have noticed a lot of cars now having different 30/40/50, etc. series tires front and back....now that I am looking.
...and I have noticed a lot of cars now having different 30/40/50, etc. series tires front and back....now that I am looking.
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The series 30,35,40 simply means the sidewall is 30% .40% ,50% of the width of the tire at it's widest point not the tread but the bulge of the sidewall. So a narrow tire MUST be a higher % if the sidewall (diameter of the tire) is to match the wide rear tire
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For anyone interested in the specifics, Jeff now has a set of 993 wide body 18" techno twists on his S4 ... from my C4S as donor. The fronts are 8x18ET52 .... a drop in fit, and the rears are 10x18ET40 .... custom fitted with a 33 0z. Lousiville Slugger. The rear fender rolling was done in multiple passes to avoid wrinkles and paint cracking - and came out looking as if it was that way from the factory. The narrow body 993 rears 10x18ET65, and would fit a S4 without rolling .... but the visual impact of the WB (ET40) wheels on the rear is stunning.
As far as tire sizes, practically all Porsches use an ~ 25" diameter: once the wheel width and ET are selected ( or fitted), a tire of the necessary width is selected by its aspect ratio to achieve this diameter.
PS ... spellcheck is dead - I now have to proof read my own crap
As far as tire sizes, practically all Porsches use an ~ 25" diameter: once the wheel width and ET are selected ( or fitted), a tire of the necessary width is selected by its aspect ratio to achieve this diameter.
PS ... spellcheck is dead - I now have to proof read my own crap
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circumference is related to diameter, and the speedo is generally off. my 305 35s are correct for calibrated speeds off the spedo and verified with radar. what this means, is that our cars are conservative speed indicating-wise
thats 26.5", so i wouldnt worry about diameter much if i were you.
mk
thats 26.5", so i wouldnt worry about diameter much if i were you.
mk
Originally Posted by Andrew Olson
Dan-
Your calcs seem to be correct. But I would worry more about circumference rather than height - although they are related,
The 265/48-18 would be the wrong aspect ratio. You'd want a 265/35 if available.
Your calcs seem to be correct. But I would worry more about circumference rather than height - although they are related,
The 265/48-18 would be the wrong aspect ratio. You'd want a 265/35 if available.
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Originally Posted by Andrew Olson
Garth
Not to be picky but... I thought all 10" wheels were considered Narrow Body and the Wide Body were the 11's like what I have.
Not to be picky but... I thought all 10" wheels were considered Narrow Body and the Wide Body were the 11's like what I have.
AFAIK all 993 18" rears are 10" wide: only the ET varies between the NB/WB cars (65/40) - this applies to both solid and hollow spoke versions IIRC.
The 11" hollow spoke rears, ET45, which I have on the C4S were from the 996TT ..... perhaps the source for yours. I think that there was also an 11" solid spoke version from the 996, but am not certain offhand.
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Originally Posted by 944S Boyeee
Garth.....do you have that pic of the new "wide look"??
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Originally Posted by Garth S
Andrew,
AFAIK all 993 18" rears are 10" wide: only the ET varies between the NB/WB cars (65/40) - this applies to both solid and hollow spoke versions IIRC.
The 11" hollow spoke rears, ET45, which I have on the C4S were from the 996TT ..... perhaps the source for yours. I think that there was also an 11" solid spoke version from the 996, but am not certain offhand.
AFAIK all 993 18" rears are 10" wide: only the ET varies between the NB/WB cars (65/40) - this applies to both solid and hollow spoke versions IIRC.
The 11" hollow spoke rears, ET45, which I have on the C4S were from the 996TT ..... perhaps the source for yours. I think that there was also an 11" solid spoke version from the 996, but am not certain offhand.
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