Wheel sizes

Brodude,

There are many specifications for both wheels and tires. For the wheels, the major specs are diameter, width and offset. 17 inch would correspond to the wheel diameter. The V6's come stock with 16" wheels so 17" would be a +1 size. The wheel (rim) width determines what width of tire can be properly (safely) fitted to the wheel. The stock 16" wheels on the V6 are 7" wide, so they can take up to a 245 size tire. Offset refers to how far from the wheel centerline (vertical dimension) the mounting plate is. The stock wheels are something like +35mm, which means 35mm closer to the outside of the wheel from the center. 7" wide = 3.5" to centerline, so mounting plate (where it bolts to the disk brake) is 3.5" + 35mm from the inside edge. Deep dish wheels often have a negative offset. All these measurements are important so check before changing anything.

For the tires, the major specs are width, aspect ratio, size and speed rating. For a 215/65-R16 tire, the 215 is the width (in mm), the 65 is the aspect ratio (in % of the width) and 16 is the tire size (in inches). This tire is 215mm wide, 140mm tall (215 x 65%) and fits to a 16" rim. If you don't keep the outer circumference the same, your speedometer will be off. For example, 215/65 and 235/60 tires are both 140-141 mm tall and so have the same outside diameter (assuming both are 16"). A 235/55-R16 would only be 129 mm tall so the circumference will be less (thus, the speedo will read high). Many people "plus size" their wheels to allow using a lower profile tire but retain the same overall circumference. There are wheel/tire size calculators to help you figure all this stuff out.

Remember, wider wheels/tires give better traction and handling but weigh more and may cause clearance problems. Wheel spacers will move the tires apart, improving handling/stability but may also cause clearance problems with the fender flares. Lower profile tires (smaller aspect ratio) will improve handling but make the ride harsher. There is *Always* a tradeoff in any modification people do.

brodude2002 said:

i read somewhere on here that for the wheels, once u get past 17in, the mm size is only used for how much u want ur wheels to stick out of the fender. is this true, or do i need to find a wheels that 45mm no matter how big it is?

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IIRC, 45mm is the wheel offset. So you'd need to make sure that whatever wheel you buy has that offset or close to it or you may have problems. 20" wheels will fit no problem.

Jimp said:

IIRC, 45mm is the wheel offset. So you'd need to make sure that whatever wheel you buy has that offset or close to it or you may have problems. 20" wheels will fit no problem.

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actually offset is based on how much the middle of the rim (width) is (off)set from the true center (where it bolts to the hub). offset does not change at ALL with larger diameter rimss. you want lower offsets to fit wider rims and keep them under the fender. 45mm offset on a 8 inch rim is not the same as a 9 inch rim.

BTW people that put 20's on mustangs oughta be shot in the street.

MakotoS13 said:

actually offset is based on how much the middle of the rim (width) is (off)set from the true center (where it bolts to the hub). offset does not change at ALL with larger diameter rimss. you want lower offsets to fit wider rims and keep them under the fender. 45mm offset on a 8 inch rim is not the same as a 9 inch rim.

BTW people that put 20's on mustangs oughta be shot in the street.

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LOL!! The part about 20's on Mustangs, I feel the same way.. I chose not to endulge in a wheel larger than 17".. But the 18" wheels would be the absolute max in my opinion...

personally i think if they had the V6 rims in decent widths (8 all around) it'd be hot as hell. sadly, ford won't do it.

i guess when i get my 20s, ill be the first one u all shoot. lol

drtc said:

i guess when i get my 20s, ill be the first one u all shoot. lol

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Don't listen to them. Get what you like.

i like the way blow by racing, and cervinis rims visually seem to "fill in the wheel well" even tho its the same diameter wheel n tire. i like 20s as long as they arent ghetto chromed out pieces of crap

18's are like the maximum size if you want performance. 17's are really the most optimal sizes on most cars but 18's for larger cars will do.

20's, however, belong on trucks. i won't shoot you but don't be heartbroken if i tell you they look like flaming ballsack when you waste your money on heavy rims.

Jimp said:

Don't listen to them. Get what you like.

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get what you like, dude.

1st off, it's your ride - get what you like and can afford. There are some great looking 20's on the market that look sweet on the Mustang. We're trying to stay old school so will most likely stay at 18's all around...