I realize that larger/heavier wheels will slightly hurt performance and gas mileage (especially if you go by the cars mpg reader and never adjust your computer to compensate for larger diameter wheels), but since the fit is not a fast car, I don't plan on spending any money to try and make it so. However, I do like a quiet comfortable ride and thought some larger/heavier wheels would help in this aspect. I only say that because on my last car (scion tC) I had 40 series lightweight 17's on it and went to chrome 18's with a smaller profile tire and a wider rim and the car rode much smoother and quieter. I realize different tire brands and models make a big difference when it comes to noise level, but do they affect ride quality as well? I assumed the wider, larger, thinner tire would ride alot worse, but it in fact did the opposite...maybe heavier wheels help smooth out the bumps? (like when you roll a lightweight cylinder across the ground and it bounces around and makes alot of noise, but when you roll a heavy one it's smooth and quiet) maybe the wider wheels are wide enough to go over the holes rather than the thinner ones that are thin enough to fall in the holes? I also can't lower my car or I couldn't get onto my drive way, and don't want a huge gap, so i was thinking some 18's...

 

Honestly there's no real benefit to big heavy tires other than looks, less sidewall shimmy and a wider contact patch.

It's also the worst kind of weight you'd be adding - the unsprung kind.

A wide contact patch, all other things kept the same, will enhance dry grip but will worsen wet grip. From my experience it'll also make your car more prone to sniffing out cambers and little bits of road acne you never knew existed.

 

There is some truth to your impressions about heavier wheels. They will resist a change in movement more than lightweight ones, and add a dampening-like aspect the compression part of the road handling equation. It's the rebound that's the problem, as the spring and damper can't bring the suspension into it's operable range quickly enough for another impact. Once you are back to cruising along, that first bump will be smoothed out, but if you hit several in succession, it would likely bottom out and get rough.

Heavier wheels might also be stronger on average for the price you pay vs. light wheels, and usually more style is afforded by the use of extra material.

In every other sense, they hurt performance.

 

g If you want to find out why heavy wheels are not a good thing, go to a good bicycle shop and ride the cheapest mountain bike or industrial strength beach cruiser they have with heavy steel rims and then get on one of their top quality skinny tired road bikes and take it for a ride. I have the lightest 15"X7" wheels made on my car and the only thing that has made more difference as far as improving speed and acceleration is a supercharger kit.... The light wheels improve the ride, handling, acceleration, fuel mileage, braking and reduces wear on all of the drive train, steering and suspension components..... A set of 4, 9.5 lb Enkei RPF1s in 15"X7" wheels will set you back much less than a top of the line bicycle wheel did 20 years ago.

 

that said....i've been to various online stores and could not find a good light wheel to replace the 21 pounders that come stock....any recommendation guys...

btw its ssm so color suggestions are always appreciated. Please throw out brands and or possible sites to shop at since Tiredirect and discount dont offer many good or cheap lightweight wheels....thanks

 

Check out TireRack.com

 

there is no benefit to heavier wheels

 

The tire is more important in terms of weight (moment of inertia) than the wheel, the further away from the center the worst the weight penalty, SO a 18 in wheel that weights 14lb vs a 16 wheel that weights 21, plus given the fact that the speedometer is affected by the full diameter not the wheel diameter makes the point of wheel size null unless the other factors are specified, my new configuration is actually lighter and smaller than the stock one, 18x7.5 with 215/35/18 tire.


NEW 18": 215/35R18 Overall Diameter:23.9 in
STOCK 16": 185/55R16 Overall Diameter:24.0 in

In some situations less tire sidewall means less tire flex, and less tire mass (lighter wheel/tire); Larger WHEEL <> Heavier WHEEL necessarily!

 

The wheel tire combination that came stock on my GD3 Sport weighed in at 35.4Lbs per corner. The Enkei RPF1s in 15"X7" mounted with 195-55-15" Conti Pro Contact weigh 25.5Lbs per corner. That is a total of 39.6Lbs of unsprung weight and rotating mass.... It is an improvement that will astound you more so than anything else you can do exclusive of adding some form of boost....

 

The flaw with that logic is the tires. You said it yourself: tire weight is important.

Engineering a tire that has less sidewall usually means it has to be heavier. You're forcing the narrower sidewall to support the same amount of weight and strain, so more reinforcement is required. Reinforcement adds weight. A same-overall-diameter tire with a taller sidewall profile usually weighs a lot less.

Very few sites or stores actually post how heavy their tires are when it's actually the more important factor in the whole scheme of things around unsprung weight.

The placement of the weight is also detrimental. Given you have a lightweight wheel but a very heavy low-profile tire, there's more rotational inertia or rolling resistance because the engine requires more torque to turn the wheel. The weight is farther away from the hub.

It's akin to turning a rod fixed on one end with a weight on the other end. All things kept the same, the longer your rod, the more effort/torque you need to turn the whole contraption. That's exactly what happens with bigger lightweight wheels with heavy low-profile tires...your bigger-diameter wheel is your longer rod, and your low-profile tire is your weight.

The same reasoning explains why figure skaters and high divers pull their arms closer to their chest: they spin easier and faster that way.

 

Tire weight is more important, I think I said it, and the sidewall is less prone to flex do in part of the size of it, not it having more or less material, as a matter of fact you would have to put more material on a taller sidewall than in the smaller one.

15lb Volk + Eagle asymetric F1(215/35/18) at 20lb = 35lb, but it will never be lighter than a good 15" wheel/tire combo (like the good example by Texas Coyote), but I just was stating the fact the large wheel is not necessarily means heavier than the 16 you are replacing, are taller once the tire is installed. And what I mentioned is an example of real life I weighted both combos on my example, it is not just theory, cheers!

 

Possible benefits of larger WHEELS (not tire/wheel, LOL) bigger brake clearance, less sidewall flex (without extra material), and for those of you with an scale, please weight tires and see my point, don't just ASSume; The stock tire/wheel combo is HEAVY, very HEAVY, has a wimpy sidewall and a very weak contact path.

Some BETTER tires are lighter than regular tires for the same reason some BETTER wheels are lighter than regular wheels, BETTER materials. Just like with bikes a good road bike tire/wheel is a lot lighter than a BMX BIKE Wheel/tire from Walmart's

 

I'm awaiting tire weights. I think you mentioned just your wheel weights.

35-profile 18s aren't lightweight. Doesn't matter if the weight's the same, the weight distribution is also farther off the hub, so rolling resistance is still greater.

 

"I'm awaiting tire weights. I think you mentioned just your wheel weights."... 35-profile 18s aren't lightweight?

I did already "Eagle asymmetric F1(215/35/18) at 20lb" THAT is my tire weight! Also remember that tires get filled with air (and yes it also is a weight constant) and my tire uses less of it than the stock one.

Doesn't matter if the weight's the same?

Yes it does!

the weight distribution is also farther off the hub, so rolling resistance is still greater?

That is a true statement, by itself... 100% TRUE!

 

I'm not sure which model you have, be I believe the stock 16s on the GE weight 17.5 lbs. Anyone know for sure?

 

if bigger heavier wheels have more weight towards the outside (heavier low pro tires for example) wouldnt it be easier to spin? (think of a string with a weight on the end and spin it around, it's alot easier than the same string with the weight near your hand) the extra weight on the outside equals more inertia/force moving the wheels, but i'd say alot of this only applies to heavier/thinner tires and when the bulk of the wheel weight is towards the rim, not full faced heavy-all-around rims. Additionally, most of the down sides of heavier wheels are negated when you adjust the computer to the difference in wheel diameter like most domestic trucks/SUVs can. without the adjustment, your revs will be way off, thus hurting performance and MPG or helping depending on the difference. Smaller diameter wheels will also throw the revs off fooling you into thinking you're getting better MPG than you really are since the trip meter will be off, as well as better performance due to the higher reving engine making people think it's got more HP. I'm sure it's posted somewhere, but does anybody know the weights of the 09+ OEM sport rims and tires seperately?

 

The 15" wheels on the GD Sport models weigh 17.4 Lbs each... I have a set of 16"X7" Final speed Eraser wheels I got from J.Crimson with 195-45-16 tires that are lighter than the stock wheel tire combo and about 1/3" smaller in outside diameter.. The speedometer on the fit with stock tires is reading roughly 3 MPH faster than actual speed which is closer than most car speedometers.... I know what you are talking about on trucks and being able to enter the tire circumference to not have the the engine over or under revving with an automatic transmission...It's not a problem unless the difference in size is pretty drastic.... A smaller circumference tire has the same effect as changing the final drive ratio and will improve acceleration..... Once you get a heavy wheel/tire up to speed it will be harder to slow down and wear out your brakes a lot sooner.