[Ecky]

It's worth putting in a caveat for EVs and hybrids. Because they can recapture a large percent of energy when decelerating, the penalty for weight is much smaller. Perhaps less than half, in the case of my own vehicle? Where I live now, hybrids and EVs also make up almost 50% marketshare of new vehicles, and they are able to capture a larger portion of energy than older models. I do weight savings mostly because it makes the car more nimble and accelerate better.

With regards to weight, your most impactful savings will be in the wheels. I've seen various figures thrown around, but quarter mile testing with Miatas with various wheel weights suggests a factor of around 3:1 in acceleration. It would be 1:1 for rolling resistance, of course. I pulled 14lbs from my wheels, which should have been worth around 40lbs equivalent in acceleration and braking. I scored a deal on these wheels (around 1/10 new price), but if they were new, they would have been $3,000US. They decrease total vehicle weight by 2.3% and ought to improve inertia by ~7%.

A lightweight battery (4lbs?) for $200 saves around 26lbs. In my car this saves 1.4% total vehicle weight, though it would be closer to 0.8% in a more typical sedan or hatchback. This is one of the better value weight savings.

Based on the typical weight of coroplast, my Insight's belly pan weighs around 3.5lbs, without the fasteners. I'd estimate the finished weight to be under 6lbs.

I have Verus Engineering's fully underbody on my Miata. Their testing suggests the two central panels, which cover around 15% of the car's underside, are worth a ~3% drag reduction on their own. I would ballpark their complete kit to be in the range of 9-14% drag reduction, with the rear suspension covers and diffuser.

Regarding cameras, they're definitely much lighter than my already lightweight wing mirrors. The wing mirrors make up almost exactly 2% of my vehicle's frontal area. Since they also add drag, let's call it 3% of the aero of the car.

So, a belly pan + wing mirror removal could be 12-17% aero improvement. Even with the addition of cameras, it might actually be a net weight savings.


Grille blocks - between 2010 and 2011, Ford advertised a 6% aero improvement on their Mustang, and most of that was reducing the front grille size, and re-routing where the air went. I can't say if this can be extrapolated to other cars, but I run an 80% block on my Insight year-round, which ought to be better than a reduction and re-routing. The plastic for this has negligible weight.