Wheel Size?

[S.J.C.]

Hi, thinking about getting some steel wheel rims so that I can put on a set of winter/snow tyres. Can anyone tell me what size rims I should go for. Have seen some 15" x 7J's 5 stud, I know the 15" is the wheel diameter but whats the 7J.

Would these rims be suitable for winter tyres and what size tyres would you recommend.

At the moment running with 215 45 17 Tyres on the alloys that came on the car (2010 T Spirit)

[beazee]

Wheel sizes are determined by three measurements-rim diameters, rim width and flange height. A typical wheel size might be 14 x 7J. Rim diameter and rim widths are always expressed in inches, so this wheel is 14 inches in diameter and has a rim width of 7 inches. The letter combination following the rim width indicates the flange height in inches. A J rim has 0.68 inch high flange while a K rim has 0.77 inch high flange.

The rim width (7inch = 178mm) will be dictated by the tire section width and/or the tread width. The general rule is that the flange-to-flange width of the rim should be a minimum of three-quarters of the tire section width. The maximum flange-to-flange wheel width should be equal to the width of the tire tread. Narrow tires on wide rims tend to make the outer edges of the tire curl in toward the center. The result is less tread on the road, increased tire wear and a harsher ride. At high speeds, centrifugal action can pull the tire beads away from the bead seat on the rim.

Wide tires on narrow rims create a poor bead seal and force the tread to assume a convex shape causing abnormal tire wear, reduction of control with a somewhat smoother ride.

Make sure new rims have the same offset as your alloys (50 for 7J; your rim is wider than OEM 15 inch):

Wheel offset is the distance between the rim centerline and the mounting face of the spider. Offset should never be increased more than 1/2 inch (12mm).

OEM rims:

2004-2009 Prius

15X6JJ: 5X100mm PCD, 45mm offset

16X6JJ: 5X100mm PCD, 45mm offset

2010 Prius

15X6J: 5X100mm PCD, 45mm offset

17X7J: 5X100mm PCD, 50mm offset

Ken@Japan

As to tyre size anything from:

- 185/65/15 (-0.5% err),

- 195/70/15 (4.5% err), 195/65/15 (1.5% err) - a perfect combination

- 205/55/15 (-3% err),

- 215/60/15 (2% err), 215/65/15 (speed error within 5.5%)

General rule to winter tyres - the narrower and higher the better.

Source:

http://www.procarcare.com/icarumba/resourcecenter/encyclopedia/icar_resourcecenter_encyclopedia_wheels.asp

http://priuschat.com/forums/gen-ii-prius-technical-discussion/59390-2010-rims-will-they-fit-08-a.html

[Ancient Nerd]

Interesting. After a lot of chasing Toyota Customer Relations, I got the following specification for wheel sizes, after checking with their technical advisors:

• 195/65R15 91H tyres are fitted to 15X6J wheels
  
• 215/45R17 87W tyres are fitted to 17X7J wheels
  

So either:

1. It really doesn't matter about the offset. Any offset will do.
   
2. Toyota GB are totally clueless.
   

I feel that the second option has something to recommend it.

[beazee]

So either:

1. It really doesn't matter about the offset. Any offset will do.
   
2. Toyota GB are totally clueless.
   

Well, it matters when you're after aftermarket rims. It matters with any other car and Toyota is not different.

Customer Service may not even know what offset is unless you already told them :) It's not OEM rims issue to care about.

To maintain handling characteristics and avoid undue loads on bushings and ball joints, the car manufacturer's original offset should be maintained when choosing new wheels unless there are overriding clearance issues.

http://en.wikipedia.org/wiki/Offset_(wheel)

When selecting aftermarket wheels, a wheel with too little positive offset will be closer to edge of the fender, and one with too much positive offset will tuck inside the fender and be closer to the suspension components. Wheel width, offset and tire size all determine the way a particular wheel/tire combination will work on a given car. Offset also affects the scrub radius of the steering and it is advisable to stay within the limits allowed by the vehicle manufacturer. Because wheel offset changes the lever-arm length between the center of the tire and the centerline of the steering knuckle, the way bumps, road imperfections and acceleration and braking forces are translated to steering torques (bump-steer, torque-steer, etc) will change depending on wheel offset. Likewise, the wheel bearings will see increased thrust loads if the wheel centerline is moved away from the bearing centerline.

http://en.wikipedia.org/wiki/Wheel_sizing#Offset

[sjrainsford]

What I haven't seen mentioned is the centre bore. You'll find it's 54.1mm.

And by the way, they're the same size and fit as Toyota Celica and Avensis wheels. You should find a fair few Celica and Avensis steel rims knocking around for sale. I'm sure there are others with that size, I just remember that mine were that same measurement.

Hope that helps!