EFF[[Buhrrito]]CEE

Ok So. . . . im running 235/55/r16 on my 7 i upgraded from 15 to 16 its not that bit but i have a question. the tires on my car look really beefy, like the sidewall part. would that contribute to the big sidewall? im wondering why the sidewall doesnt look skinny. the tires on it before were 205/60/r15.

dawicka2

235 is wider. 55 and 60 = not significantly different sized sidewalls (5%).

so....your old 205s were much more narrow and stretched on to the rim lowering the sidewall.

If you want a 235 width........go 235 40 16 or they will look like they belong on a blazer.

john ny

ATRON3000

205*0.60=123mm
235*0.55=129.25mm

The sidewalls look bigger because they are bigger

plus what he said about the 205's being streched, unless your new rims are wider

Turbonut

iTrader: (1)

As has been stated before, the tires ar just to "big" for the vehicle.
Compare the OE 205/55-16 at 24.87" diameter to the 235/55-16 tires that are 26.17" tall, and that extra 1.3" is all sidewall. The OE tires were to be 215/55-16, but way back in the 80's that was not a very popular size, so they installed the 205/55-16. I actually run the 215/55-16 front and 235/50-16 rear which are fine, but finding a 235/50 other than Toyo is tough, as mine are Continental.

rx7racerca

iTrader: (1)

The sidewalls being "stretched" (due to being mounted on too-narrow rims, assuming the the stock ones or stock size were retained) would tend to make them look shorter, not taller. The sidewall height is more diagonal to the pavement, so viewed from the size it will be foreshortened. Barring the unlikely event the 205's were mounted on 8 or 9" rims and they were "stretched" to appear shorter.

The real issue is too tall a tire - the OP went up 30mm in width while retaining the same profile as stock turbo tires(205/55-16). 30mm*.55=16.5mm. *2 because that 16.5mm is added at the top and bottom of the rim gives an increase in diameter of 33mm, or 1.3", as turbonut2 noted.

The original tires, since he upgraded from 15s (so the car was/is NA presumably), were 205/60-15, with an original nominal diameter of 24.69", very close to the stock turbo tire/rim diameter of 24.88" from 205/55/16s. 235/55-16 gives an overall diameter of 26.18", more than 6% increase, all from sidewall, so yeah, it's gonna look tall like an SUV tire, and it's going mess badly with speedo (giving slower than actual readings), and gearing (giving your torqueless NA even slower acceleration, although a lower-revving top gear cruise).

Since 235/40 and 235/45 don't exist in a 16" size, his best choice will be 225/50-16 or 245-40/-16 - although the 245's can have clearance issues, especially at the front.
Width/ Profile/ Rim/ Overall Diameter/ % of OE
205 60 15 24.69 100
205 55 16 24.88 100.7814992
225 50 16 24.86 100.7017544
225 50 15 23.86 96.6507177
235 55 16 26.18 106.0446571
235 40 16 23.40 94.80063796
235 45 16 24.33 98.54864434

rx7racerca

iTrader: (1)

Caught a mistake of my own - in a 16", 245/45 would be the correct sizing, not 245/40. Again, fitting 245s requires careful attention to offset for clearance to both the strut and fender lip at the front - often it requires rolling the fender lip.
225/50 in an aggressive performance tire may well give the same or even greater width than a typical 235/55 anyway. Plus, again assuming this car is NA, lower rim/tire mass makes a noticable difference to responsiveness, so going big is more style than substance.