apexanimal
Member
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- 2013 CX5 Sport, 6mt
^ Better accel, braking, city mileage, more responsive suspension, etc...
Losing unsprung weight is a big deal...
Losing unsprung weight is a big deal...
Show me your CX-5 wheels
- Thread starter minhhh
- Start date
...And 20 lbs is a huge difference hoisting each wheel-tire above my head onto the storage rack in my garage, as well as lifting them onto the hubs for mounting
I hope you don't believe everything you read just because it's in print.
The CX-5 is a good candidate for benefiting from lighter rotational mass because of it's relative light weight and low power. A heavy hot rod with a high powered engine will see much less relative benefit.
If you doubt the energy required to spin four mounted tires up to 30 mph, I suggest you do some experiments with a wheel mounted on an old school wheel balancer with good bearings. Spinning all four wheels/tires up to speed is a significant part of the energy required to go from 0-30 mph. I have motorcycles making well over 100 hp and, even with only two wheels to lighten , switching to lighter wheels/tires makes a noticeable difference in acceleration.
Editors of Hot Rod magazines are not known for being the smartest people around and it would not surprise me if they would make such a stupid pronouncement after one casual "test" in which they failed to account for other variables (like running the tests on different days or under different temperature/humidity conditions). In a timed 0-60 with a high powered hot rod, traction at the launch plays a major role in the timed result. And a lighter wheel/tire actually makes it more difficult to get a smooth launch. With the CX-5's relatively low power and AWD, this factor does not come into play. Trust me, it is definitely possible to notice the loss of 20 lbs. of rotational mass on a car like the CX-5.
I'm curious what the lighter wheel effect is on the braking distance:
http://blog.tirerack.com/blog/letters-from-luke/give-me-a-brake-
http://blog.tirerack.com/blog/letters-from-luke/give-me-a-brake-
I think the OEM wheel/tire combo isn't especially heavy, and all instrumented testing is showing very good braking with OEM 17's and 19's. Therefore I don't expect many owners to invest in expensive forged wheel for CX-5.
Of greater concern is the impact on braking distances of super big and heavy wheel/tire combos (20"-22" diameter)via aftermarket.
Of greater concern is the impact on braking distances of super big and heavy wheel/tire combos (20"-22" diameter)via aftermarket.
The CX-5 has very good braking numbers. It's possible lighter wheels could reduce that minimally, but not much. The real benefit would be if one needed to make repeated high speed stops (especially in hot weather) or high speed stops down steep grades. The lighter wheels would allow more stopping before brake fade kicked in (assuming the lighter wheels had similar hub contact area and could transfer excess heat into the wheel as efficiently as the OEM wheels). But in normal street driving this would not be an issue. Lighter wheels will extend the life of the brake pads and rotors by a few percent because they will not be doing as much work.
CX-SV - True, forged wheels are expensive (and of limited availability). But the OEM wheels are gravity cast aluminum and there are a number of non-forged options for considerably lighter and/or stronger wheels with reasonable prices. The OZ Alleggerita's I purchased recently were $319 each and are cast using a low pressure casting system followed by a mechanical process that further strengthens the wheel through a peening process that strengthens the structure of the aluminum similiar to forging but to a lesser extent. The low pressure casting system results in a quicker and more uniform pour which provides more uniformity in the strength of the casting to begin with and costs considerably less than forging and allows a wider variety of wheel designs. Sticking to the same wheel size I was able to drop a whopping 7.5-8 lbs. per rim. Other than cost, there is no downside whatsoever (unlike a lot of other types of vehicle "upgrades").
Unless money grows on trees there is not a compelling reason to change out the OEM cast wheels. But, in my case, I needed another set of rims for winter tires anyway so it was a cost effective upgrade.
Rotational inertia and gyroscopic forces are not linear effects when taken together, so a 7lb differential on each hub will make a difference, which would be more perceptible on a vehicle with a lower power-to-weigh ratio and effective suspension geometry like the CX-5, less so on a old Buick or some such vehicle.
An extreme analogy would be dropping an elephant and an ant the same distance, say ten feet, visualize the impact of each one....... That is the weight response to a bump, now spin them, and repeat.....of course the elephant would roll further after hitting the ground, but getting him up to rpm would take longer.....
An extreme analogy would be dropping an elephant and an ant the same distance, say ten feet, visualize the impact of each one....... That is the weight response to a bump, now spin them, and repeat.....of course the elephant would roll further after hitting the ground, but getting him up to rpm would take longer.....
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Yeah I based the 'shop off of a GT and just scaled the wheels to be the same as the stock 19's. Tire rack only has them up to an 18" size for this application but if I were actually to get RPF1's that's probably the size I'd go for. Even at 18" the wheels are only 17.6 lb!
http://www.tirerack.com/wheels/Whee...lse&filterNew=All&filterWeight=All&sort=Brand
http://www.tirerack.com/wheels/Whee...lse&filterNew=All&filterWeight=All&sort=Brand
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- 23 CX-5 Premium
It's a nice clean design BUT, I think the whole black wheel thing is the worst thing that's happened to automotive design in the last 25 years. I'll be soooo glad when it's run its course. The only way black wheels work for me is when there's some kind of contrasting finish (silver or color) on the rime that defines the size or design of the wheel. Otherwise, from a distance, black rims make a vehicle appear to have amorphous lumps pf coal lurking in the wheel wells. But, what do I know?!(spin)
