I know its a light car, but compaired to the new Mazda 2 its got a few pounds, I already have an Oddsey light weight battery, 11lbs or so. I do need the rear seats. Any seceret parts to remove that are unnecessary to help my fit get fit and loose a few pounds? Sorry if this is a covered topic. I didn't see it on a search thanks!

 

https://www.fitfreak.net/forums/2nd-...t-edition.html

 

Reducing rotating mass and unsprung weight is the best place to begin. Replace your wheels and tires with lighter ones, the benefits are immediately noticeable and everything between the engine and wheels including the suspension and steering components will work better and last longer.

 

TC is right, before you start unbolting your rear seats, get the lightest set of wheels that will stand up to the roads you drive on. A few pounds here is worth many pounds of sprung weight.

Zach

 

And lighter tires. Tire weight can vary quite a bit between brands.

John

 

It appears that the rear seats and spare are about 80 lbs, not sure if that's really worth it but I might do this when I go down to the Dragon in the fall, I know it would be worth it there for sure

 

Removing the 80 lbs of rear seats, belts, spare tire and jack is definitely worth it if you NEVER use the rear seats. If you do, it probably isn't worth the hassle swapping all this crap in and out. I pulled all this stuff out of my Fit the first week I got it and have never replaced it. I keep a can of "fix-a-flat" in the pocket in the back of the passenger seat.

The biggest performance increase I noticed was when I swapped lighter wheels and tires...but the actual gain in performance probably came more from decreasing the overall diamter of my wheels/tires than the decrease in unsprug weight. Reducing wheel diameter effectively increases your final drive...this alone can dramatically increase acceleration.

 

Don't forget tire width as well. There is a significant increase in weight and rolling resistance going from say, a 195 series to a 215 series tire.

From my extensive research (including call the manufacturer for inidividual tire weights), the General Exclaim UHP is the lightest weight 195/50/15 tire on the market. You could save as much as 2-3 lbs per tire compared to other tire manufacturers of the same size tire. Unfortunately, these were on back order across the entire country when I bought my wheel/tire combo.

All things being equal, you will probably see more performance gain from a lightweight tire than you will from a lightweight wheel...combine both and you get synergy.

 

He speaks the truth. It can get really complicated when dealing with rotational inertia. Two wheels that both weigh exactly 15lbs do not perform the same. This is because the closer the weight is to the center of the wheel, the less rotational inertia it has. To quote wikipedia:

"The moment of inertia of an object about a given axis describes how difficult it is to change its angular motion about that axis. Therefore, it encompasses not just how much mass the object has overall, but how far each bit of mass is from the axis. The farther out the object's mass is, the more rotational inertia the object has, and the more force is required to change its rotation rate. For example, consider two hoops, A and B, made of the same material and of equal mass. Hoop A is larger in diameter but thinner than B. It requires more effort to accelerate hoop A (change its angular velocity) because its mass is distributed farther from its axis of rotation: mass that is farther out from that axis must, for a given angular velocity, move more quickly than mass closer in. So in this case, hoop A has a larger moment of inertia than hoop B."


In other words, the tire is the single most important part of the rotational inertia equation because it is the furthest out from the center axis. Of course this is a balancing act because you are also sacrificing traction.

 

I was looking for the mathematical equation demonstrating rotational inertia in terms of radius...I recall an equation relating inertia to mass x radius ^2. But this may not be exactly correct...

I've also looked into lightweight brakes (steel rotors, aluminum rotor hats, aluminum calipers) to improve acceleration of the Fit, but the majority of the mass of the rotor is still distributed the same distance from the axis of rotation. And...reducing rotor diameter is, admittedly, not an ideal way to reduce sprung weight

 

Be sure and reduce the pressure of your rear tires or add pressure to the front tires after removing the seats and spare.

 

Thanks you for sharing