im looking into buying a new set of wheels and i dont understand whats the difference between having a lower offset on a wheel thats 15 x 7 or having a high offset on a wheel thats 15 x 8???

the lower the offset the wider the wheel right? where you have to camber it in to tuck it.

but i have rota group n 15 x 6.5 +40 and i want to go with something a little bit wider but i dont understand the difference between offset and the width of the wheel dimension

if anyone can help me that would be great

thanks

 

FIRST, decide on what size and make/model tires you're going to mount on the wheels. THEN decide on the wheel width. You don't want to wind up with wheels that are too wide for the tire size you need for your car.

What kind of car is this for (year, model, version)? And how do you plan to use it (racetrack, daily driving, snow, etc)?

 

i put 15x8 on my ef and this is what i got. they rub some on the big bumps.

 

You probably have tires that are too big for your car, and possibly too small for those wheels. Your car should use 195/50-15 tires, which can only be mounted safely on wheels 7" wide or narrower (5.5-7.0"). The smallest tires that can safely be mounted on 15x8 wheels are 225/45-15, which are too big for your car.

 

This is explained in the FAQ as well as numerous other websites.

15x8 means 15" diameter wheel with an 8" width. 15x7 is a 15" wheel with a 7" width. Regardless of offset, 8 inches is still wider than 7 inches.

Offset tells you the distance of the mounting surface (where the wheel will be affixed to your hub) with reference to the centerline of the wheel width.

+40 means that the mounting surface is 40mm towards the outward face, from the centerline of the wheel. Similarly +15 means the mounting surface is 15mm towards the outward face from the centerline of the wheel. On the other end, an offset of -10 would put the mounting surface 10mm towards the rear face of the wheel with respect to the centerline.

 

The lower offset wheels are gonna give you that staggered look.Before you decide on any of that I agree with nsxtasy,That is very important.

 

Yup. The width (as well as the diameter) is measured at the bead, the indent in the wheel where the inside edge of the tire is seated; it is NOT measured from the outer edge of one lip to the outer edge of the other one.

Tire manufacturers publish specs on what wheel widths are approved for each model and size tire they sell.

 

here you go john... scroll to the bottom

http://www.vipstylecars.com/forums/s...ad.php?t=13074

 

^ that link helped a lot. thanks for that

but now that fully made me understand offset alot more. can i have a 15x7 wheel with +40 offset and a 15x7.5 inch wheel with +40 offset and they still stick out the same distance?? its just making the point where it bolts on go in or out...or because the width is changed..that makes the way the offset is different because theres a bigger area from the middle of the width where offset is measured?

 

No, they won't. In your example, both wheels have the same offset, so the wheel centerline is 40 mm over from the mounting surface for both wheels. The 15x7.5 wheel is 1/2" wider, so the extra width is equally distributed between the inner face, which will protrude 1/4" further inward, and the outer face, which will stick out 1/4" further.