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Discussion Starter · #1 ·
Well, with Autocross season about to start, I've decided I'm going to pick up some stickier tires that can serve both daily driver and autocross duty. Our stock size is unique to our car, so I will be getting 195/55 R16s. Tentatively, I have decided to go with Bridgestone Potenza RE760 Sport tires. They are a good bit heavier (and stickier) than our stock tires, so hopefully it wont have too much affect on acceleration or gas mileage.

I will report back with photos and a review once they are on!
 

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Discussion Starter · #3 ·
A 195/55/16 is 10mm wider and about 4mm shorter sidewall vs the stock 185/60/16. That makes them about 0.3" smaller in diameter. That means when the speedometer reads 65mph, I will be actually driving 64.22mph... Not a huge difference in size.

The main reason I'm adding them is they will have more grip and a stiffer sidewall to increase my handling ability. And this is the closest size I can get that will fit on a 5.5" rim.
 

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Discussion Starter · #4 · (Edited)
Ok got them installed! Haven't driven but a mile or so on them, so can't really comment, but for those worried about the size - don't be. Here are some pics! (Sorry, car is dirty)







 

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Very nice; I've been considering the same tires to replace my stock ones as well. Did you also consider them in 205/50?
 

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Discussion Starter · #6 · (Edited)
^ I did. And in autocross, there is a trend of "the wider the tire, the better", however I have never liked the feel of tires overly wide for a wheel. My instincts were further confirmed when I read an article by Andy Hollis (very prominent Autocrosser, and former Mazda2 competitor).

Andy says: "The tendency is to cram the widest legal tire on the widest legal rim that will fit and go for it. But that is not always the optimal solution, as street tires do not have the same super-stiff sidewalls as do the best R-comps. Sometimes it makes sense to run a narrower tire for a given rim fitment. From the testing we've done, we find that a good rule of thumb is that the optimal rim is the same size (rounded up to the nearest half-inch or so) as the tread width (not section width!). So a 205/50-15 tire with a typical tread width of 7.5" is best on 7.5" rim. An 8" rim will work, too, but it will be majorly stretched on a 9. Likewise, it will lose some performance on a 7, and will lose a LOT going down to a 6 or 6.5. Similarly, a 225/45-15 with an 8.2" tread width works best on at least an 8.5" rim and loses a fair bit on a 7.5". The rest of the article is HERE

Since the iA comes with a 5.5" wide wheel, I wanted to get the narrowest semi-performance tire I could on the stock rims (without drastically changing the diameter). Had they made a 185, I would have probably went that route...

But even taking Autocross out of the equation, it's not like these iA's have lots of tire shredding power, so I am pretty sure a 195 is plenty wide for now!.. ;)


Oh, and if you are thinking about the same Bridgestone Potenza RE 760s, they are on sale through February 29th for 20% off most places. I went to a local Firestone (not sure if they are nationwide) and got these for $447 installed. Cant beat them for the price!
 

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I think some tire companies will match that price and even beat it by a small percent more. something good to consider for those looking for a really good deal, although they might require you install with them.
 

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I know that Toyota is having a sale where you buy 3 and get one for a dollar. What alternate tire size would be best on the stock rim?
 

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Discussion Starter · #9 ·
Not sure what the BEST size is, but the 195/55R16 works fine. Its just the maximum width I (personally) would go on the stock wheels. Its only a tad bit shorter (about 0.3" in diameter). So when the speedometer says 65mph, I'm actually only going 64.2 mph. I can handle that little of difference.
 
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