Tire or the rim, what one weighs more?
 

Assuming you are after a certain diameter, lets say 20 inches to work with. What combo would weigh the least?

17 inch rim + 3 inch side wall
18 inch rim + 2 inch side wall
19 inch rim + 1 inch side wall


Obviously I am assuming the rim width, and tires are made by the same company.

Any ideas?

High quality racing rims normally weigh less than a tire, on average a tire weighs about 25 lbs and up, a high quality racing wheel would weigh from 13 lbs to 20 lbs.

If you get cheap wheels they can weigh up to 30 lbs

If that's true then it would be best to put the largest rim possible on the car? Get a good rim that is 19-20 inches and rubber band for a tire.

Over all that would give the lowest combo.

My 17x9 RPF1s weigh under 16 lbs. The 255/40 BFG KDWs wrapped around them weigh...more. I haven't weighed them, but my wheels are definitely more than 32 lbs apiece.

On the other hand, a 17x8.5 OZ Competition weighs over 30 lbs.

Yea I understand that but I am trying to compare the same rim just different diameters.

So in your example.... you have 17x9 RPF1s and it weighs around 16lbs. For arguments sake say your tire is another 16 giving a grand total of 32lbs.

My question is with light weight rims had you gone 19x9 RPF1s you would be around 21lbs for a rim but you would need a very small side wall tire. So would that be a 10lb tire? Over all savings would be 1lb per tire.

These are just made up numbers but I hope you guys get the point. I am at a cross roads right now and I am trying to decide on what direction to go.

I currently have 19inch racing harts. They are not the lightest rim that is for sure but I love the look.

After seeing another member post his I have been eye balling the forgestar 14 because they are light and pretty nice. But if I am going to switch setups I want to find the lightest combo. 18 or 19's?

Remember, the less sidewall you have, the more harsh your ride will be, and the more likely you bend a rim if and when you hit a pothole. :)

Toyo makes lightweight tires. I'm not sure what T1-Rs weigh, but the Miata crew used to love T1-Ss because of the weight savings. Also, if I'd have had a few more bucks when wheel-buying time came around, I probably would have got a set of Volk CE28Ns. Superlight, strong, and one of the best looking wheels on an FD, IMO.

Wheel buying rule= Light, Strong & Inexpensive. Pick two. ;)

You have to look at overall diameter, where you count the sidewall twice. A stock FD has a rolling diameter of just under 25 inches, so that should be your benchmark.

I weighed two sets of wheels/tires:

17x8.5 with 245/40 and 17x10 with 275/40 Fikse FM5s with Kumho XS
18x9.5 with 255/35 and 18x10 with 265/35 Enkie RPF1 with Yoko AD08

I was surprised to find the weights pretty similar. IIRC, the front were around 42 pounds each and the rears were around 46 for the 18s and 48 for the 17s. It's all posted in my build thread.

Keep in mind that the tire is further from the center so that weight matter more than the weight of the wheel. One reason I moved away from Bridgestone tires.... I loved my old S02s, but if you peruse Tire Rack you'll be surprised by the weight differential.

Have fun with this, complements of Castro (MROWZ?): http://www.miata.net/garage/tirecalc.html

If I remember correctly, a smaller wheel with more tire generally is lighter, all things being equal. It's hard to beat the weight of a stock third gen wheel with a light tire. Many of us want to try and get a bit wider tire under there - some for style, others for performance.

IIRC best handling comes from about an inch of diameter increase on a typical wheel, and a sports car wheel might already be bigger. Beyond that there's not much to be gained and eventually you worsen handling from the weight. Smaller wheels are cheaper of course and give slightly better mpg. Smaller tires improve handling but give a harsher ride and increase the risk of damaging the rim on a big bump, as said. From this it seems the ideal sporty setup would be a reasonably big wheel, perhaps equal to the highest stock size, as light as you can afford and narrow but not rubber-band tires.

IIRC tire/wheel width (left to right) improves dry handling but worsens hydroplaning.

Sources: Consumer Reports and random car sources like these forums. Take with a grain of salt.

Meh I just weighed my fronts. 19x8.5 + 245-35-19

50.3lbs!

I didn't bother weighing the backs as they are only going to be heavier :s.

One of you guys needs to sell me some cheap forgestars!

There would also be factors regarding where the weight is in relation to the center of the wheel, because weight on wheels is rotational. Higher mass tires on the outside of light rims will require more work to spin.

toyo's website lists the tire weights, i assume other brands would too.

tirerack has weights for all their tires