What difference could 1 POUND make? //
Back with another episode of #FAQ , where we answer popular questions that we frequently receive across our social media channels. Looking to upgrade your ride with lightweight wheels? In this informative video, we address the most frequently asked questions about lightweight wheels. Join us as we dive deep into the world of lightweight wheel technology, discussing their benefits, performance enhancements, and compatibility with different vehicles. Whether you're a car enthusiast, racer, or simply curious about optimizing your vehicle's performance, this video is a must-watch. Stay tuned for expert insights and practical advice that will help you make an informed decision when it comes to choosing the perfect lightweight wheels for your needs.
Lightweight wheels can make a huge difference in the performance of your vehicle, but before you go ahead and buy the lightest set you can find, you're gonna wanna take a few things into consideration.
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#automotive #educational #wheels
Well done and somewhat informative video, but I like to correct a few things. Rotational inertia has no relation to static weight and so no equation can be derived universally since not all vehicles run the same size wheels and tires, so I was disappointed when a sponsored racing team falsely made this 8.5:1 claim. Any physicists will tell you that more mass away from the center will require more effort to spin, this has been detailed by other KZheadrs such as Engineering Explained. That means that the tire's weight (given the same wheel specifications) has a greater affect in rotational inertia as it sits the furthest away from the center. Shaving 10 pounds off a 20" wheel will not be noticeable, but going to a smaller 17" wheel with the original 20" weight will have a much larger effect. Moving along. When talking about linear motion, up and down, lighter will always be better as it can change direction quicker but only shows an advantage if it is on a bumpy course (which most tracks and autocross are not). Turn-in is not really affected with lighter wheels so I did not understand the concept of better "turn-in" as that is the suspension reacting to the sprung mass, not the other way around. This is why racing teams do not focus on wheel weights, and instead focus on other aspect of the car such as suspension, tires, aerodynamic, etc.
100 percent this and testing in real life is about 2-2.5 lbs is one rwhp for a 18” rim or the equivalent to 1 lb of unsprung weight is worth about 2 sprung and not anywhere close to 8.5
Something else that was not discussed much are the various racing applications. You will notice that racing applications that emphasize bursts of acceleration will often prioritize lighter wheels. For example drag racing or autocross as autocross courses can be very stop-go and short with tight turns. Racing on a track that carries more speed or even racing at a salt flat for a top speed might prioritize aero or grip much ahead of weight. Also you will find folks running heavier wheels simply because they need to in order to fit over large brakes or certain tire sizes will only work well with the larger wheels. But yes, if all specifications and variables outside of weight are equal, then generally lighter is always much better. Most manufacturers will prioritize strength, cost, fashion, and aero for fuel economy for the wheels they choose to run. If you switch them out for a hypergram, rpf1, or a good forged wheel, you will notice a solid difference when driving day to day with acceleration and how your suspension responds to road imperfections.
10lbs off of a wheel／40lb rotational weight IS noticeable if the tyre weights remain the same or close enough to.
"This is why racing teams do not focus on wheel weights" What do you mean? Race teams normally run the lightest wheels they are allowed to run (often magnesium alloy), except for in rallying where strength is more important. Carbon fibre wheels are usually banned in circuit racing, for whatever reason, but motorcycling enthusiasts usually find improvements in acceleration with carbon fibre wheels compared to OEM sportbike magnesium alloy or aluminium alloy wheels (except that the lighter wheels do reduce traction in wet conditions, assuming the tyre make & size is the same). Honestly, I would be surprised if a racing class set a minimum wheel weight and minimum upright weight and then the race teams (& their wheels supplier) did not aim to hit those weights... That would be *very* unusual IMO.
Static weight does play a role in rotational inertia. The static weight of an object is its mass times the gravitational constant. The moment of inertia is the product of the mass with the square of the distance of the mass from the axis of rotation. The mass, or weight, figures into both. The car with lighter wheels and tires will turn in more easily because its angular momentum is less and will thus need less of a steering torque to impart a given angular acceleration, effecting an angular deflection(steering}. Consult any General Physics text in the Mechanics section under rotational dynamics. The forged magnesium monoblock wheels on my car resulted in a smoother ride with a more compliant suspension plus a faster steering response to steering inputs, as compared to the forged aluminum wheels my car came with.
Facts I running per 15 pound set up on my 2020 civic slow 2.0 liter. Man it makes a huge difference in acceleration and turns.
Thanks. Useful info...👍
This is the best ever video I've seen about this topic. Just bumped into you guys but I'm definitely going to subscribe 💪🏽
We appreciate that!
Grip also depends on tire compound and aerodynamic down force or lack there of in any vehicle in question.
That was an informative video and I appreciated it. But it would be really helpful if Kong had a fitment guide on there website like Apex does
Very informative 👏, just grabbed the 15×8 ultragram in carbon bronze
20x8.5..+45
It made a huge difference i went from a stock 17" to 18" lightweight. I didn't have any expectations and i was really pleasant surprised how much difference it made in how the car drives
Totally. A big difference in feel coming off stock wheels onto something more lightweight.
Im looking for magnesium Japanese of course rims
FAQ ❤
Also, when are those new forged wheels coming out?
Still coming out this year! Just had a bit of a delay on them.
Would 1 lbs throw off the AWD system
Cool. How do we submit a question to be answered?
Right here in the comments.
Hey mate what is the konig model of the wheels on this video’s photo?
Hi Mikko, that is the Ultragram in a Carbon Bronze Metallic finish!
Sprung weight doesn’t affect the performance and gas mileage? As long my wheel is lighter I get more benefit out of it.
Yes it does, but differently. Sprung weight is basically the weight of the vehicle above the suspension, so in effect- a heavier vehicle will negatively affect your vehicle's performance and gas mileage.
Does 1 pound equals to 8.5 pounds in the rear wheels if its a front wheel car? Its just pulling the rear wheels
That mass is still rotating creating forces. It does affect all wheels, powered or not.
And 8.5:1 is a fake info. Its around 2:1 por tire 1.6:1 wheel, 1.2:1 brake disc.
This should be tested on bigger cars, since ford focus, small Nissan its hard to scale😅
What percentage of fuel economy you think is possible with a lighter wheel?
Some testing done by TireRack on their website estimates about a 5% improvement in MPG with a 3lb reduction per corner. We can't really give a definitive answer on that but the logic makes sense.
No. It does not. A 1t car at 100km/h has around 400kJ of energy. 2kg reduction per wheel (even assuming whole mass at the rim) gives you something like 250J gain. That's completely negligible.
You will actually gain more fuel economy with an aerodynamic wheel versus a lighter wheel. In cycling we always note that once you are moving over 10 mph, aerodynamics becomes the greatest force of resistance. You will notice hybrid and electric cars always have aerodynamic wheels versus light ones. That is because the industry is hyper conscious about range. Tires with a low roll resistance will also increase your fuel efficiency way more than light weight wheels. Side note, I am a light weight wheel whore and still choose lightweight wheels because I do not care about maintaining top speed or fuel economy. I prefer the snappy acceleration over mpgs and carrying top speed
im not feeling the music tho
Noted, thanks for the input, we'll look to switch it up!
Mitsubishi Mirage 2023. I don’t want to change the tire size but want to go lite. What do you recommend?
Rpf1 makes 8 lbs a piece 14" rims and 9-10 lb a piece 15" rims. Really cheap on emnotek website right now just make sure you get the right size and bolt pattern that'll fit. Your stock wheels not including tires are probably atleast 17 lbs a piece
Some of these wheels COST WAY too much dam money 😂. I've seen gutted cars at the track only shave .3-.4 seconds from previous times. If you wanna shave a full second, you need more power. Sorry to bust yall bubble.❤
Lol, there is plenty of video removing everything in the car (weight reduction), and the car is half a second faster. It's not 5 pounds per wheel that will make you faster.
Sorry, but this is a complete BS right at the beginning. While a car with lighter wheels can indeed handle better due to less unsprung mass, the inertia of the wheels vs. the inertia of the whole cat is 2-3 orders of magnitude lower so that doesn't make any noticeable difference in acceleration. Also, to make things more interesting - lighter wheels due to different distribution of mass could actually have higher moment of inertia than heavier ones!
"the inertia of the wheels vs. the inertia of the whole cat is 2-3 orders of magnitude lower so that doesn't make any noticeable difference in acceleration" You can do the experiment yourself, there are dozens of examples of people taking 0.1-0.2s off their 0-100 kph time by fitting lighter wheels, everything else being equal (same tyres, same vehicle). If it's wet, the lighter wheels do reduce traction and can increase the 0-100 kph time mind you. "the inertia of the whole cat is 2-3 orders of magnitude lower" I don't agree. You have at least two driven wheels bolted on the end of the driveshafts right, so about 40kg of rotational mass. As a percentage of the entire rotational mass of the engine, transmission etc, a saving of say 6kg on the driven wheels is not insignificant. You can gain a bit from a lighter flywheel (say 4kg instead of 8kg, the typical flywheels used on some racing cars are even less than that, they are barely there!), you can gain a bit from a small diameter multi-plate clutch (typical in race cars), you can gain a bit from a carbon fibre driveshaft if applicable, lightweight pistons & titanium conrods (obviously racing engines like Grand Prix bike and Grand Prix car engines already have this as standard)... It all adds up.
@@TassieLorenzo It's not about whether you agree or not. It's about the numbers. Do the math yourself if you don't believe me. Calculate the energy (kinetic energy of the traveling mass and rotational energy of the wheels; we may skip the rotational energy in the drivetrain for simplification). with the heavier and lighter wheels. And if we're at it - contrary to the popular myth, lighter flywheel doesn't give you more power. Yes, the dyno shows increase of values but it's only because of how the dyno works.
@@SpadajSpadajhe never talked about power or dyno at all, it's about less mass means it can accelerate faster, and that's true, period.
@@DanielBrownOre Not noticeably quicker. The difference is minuscule and the rest is placebo effect. Do your maths. BTW, mass as a single parameter is not the only factor affecting the acceleration. Moment of inertia depends on the mass but also on its distribution. That means that slightly lighter wheel in which more of the mass is placed further from the axis can actually have higher moment of inertia than a heavier wheel with a more uniform mass distribution. But that's all just nitpicking. It's not that much of a difference compared to the inertia of the whole car.
@Spadaj If you can maintain traction, which admittedly is harder to do with lighter wheels, I've personally seen videos of side by side and timed runs that give objective improvements when the difference is a good 5 lbs or more per wheel. My car has a fairly tall final drive and needs all the help it can get on a roll, so lighter wheels will certainly help a little. I'm saving my heavier wheels for winter.