There could be a slider where you can decrease the weight of the car by increasing the engineering time, to some extent.
Light weight can be obtained not only by light materials but also by reducing the amount of material.
The chassis can be designed with the right amount of material at the right place without sacrificing stiffness and safety.
The downside is engineering time.
Engineer smarter
I have to agree on this one. We don’t really have any options for lowering weight except by also lowering safety and comfort. I would love to have separate sliders for quality and weight. That being said, it’s best to let the devs focus on the big stuff now before adding smaller stuff later 
Second that - lightweight slider would be great, if the devs find the time.
You can also lower it by reducing body quality, to say nothing of the obvious stuff like lighter body materials, chassis type, rim materials, smaller brakes with air flow, etc…
That said, yes, I was just thinking there should be a slider where we could engineer lighter parts without having to make a car that everyone hates.
Yes, reducing body quality is something I like to do in sandbox mode. As for the Lite Campaign, the reliability penalty can be ameliorated with a bigger engineering budget (lowering quality lowers the engineering time anyway, so it’s even quite feasible), though the prestige penalty remains.
I think that balance is pretty realistic. Look at the supposed lightweight constructions in real life, all alloy 1.7 ton cars, etc. :s As bastormonger points out there are ways to get lighter cars, but for a price of either money or prestige / comfort.
Yeah, sometimes one can get the impression that companies build 1.4 ton cars, then pour in 300 kg of carbon fiber into them with a cement mixer and call that “lightweight”…
Anyway, I think the appeal of a lightweight slider in the engineering tab would be the ability to design lightweight exotic cars. Lowering body/fixtures quality works quite well for Delivery/Utility type demos where prestige is not a concern, but not so much for, say, Light Sports etc. Actually, maybe a prestige rather than lightweight slider (optimizing panel gaps, wind noise etc.) would do the trick so you could drop body/fixture quality with relative impunity as long as you throw enough money at it.
Another possible approach would of course be to simply reduce the prestige weighting on sports oriented exotic demos (light sports/sports), since buyers of this type of cars often don’t care much about panel gaps and stuff.
EDIT: With the latter in mind, it just might not be worthwhile to add a slider if a “lightweight engineering” effect is already kind of in the game and might be extended to more demographics with minor balance tweaks.
A lot of weight reduction isn’t just thinning out the materials and calling it a day. It’s finding out where you can thin them out without consequence. I read an article back in the day about doing just that: Drilling holes in non-structural brackets, trimming away excess casting materials, using lighter materials for things like radiator shrouds and fender liners. Stuff like that takes more planning, and would make the vehicle lighter, but with no appreciable negative consequence to the end user.
Would remove all the challenge out of making your car lighter though.
Also, it would make the game more like GearCity abstracting away an otherwise intriguing process and making other design choices weigh less … pun intended.
I don’t understand why - literally everywhere else making something “better” is balanced by making it more expensive. Adjusting the quality slider on valves is universally positive. Adjusting it on intake is universally positive. Same for tires, brakes, aerodynamics, exhaust, forced induction, etc. If the balancing works there, why would it not work for bodywork?
It just bugs me that everywhere else you can focus on something that is a straight-up improvement except for the body.
You do have the quality slider there that makes it better. I think it is just your definition of better that doesn’t align with what the slider does. When you look at the industry, better obviously doesn’t mean lighter, as the “better” cars weigh A LOT. So the slider just does that, improves everything but definitely not weight.
Nope. It isn’t as straight cut as you think it is. Engine setup and exhaust weight (yes, that IS a concern when building a superlight) isn’t always “more quality = better”
Bear in mind, better quality usually allows you to run a slightly smaller diameter at the same peak flow, which means you get a little better efficiency, noise and weight for a “better quality” exhaust. Apart from cost/engineering, it’s just better.
There are a fair few spots where the quality slider seems odd to me, for example this one’s been removed, but it seemed odd to me that you could choose between I beam and H beam connecting independently of the quality slider. Bottom end is one spot where I think quality and “heftiness” should be set independently.
For example, I’ve got an engine that I’ve been messing with that has a forged crank, heavy forged rods, and forged pistons, and this setup is overkill both for RPM ceiling and max torque, but heavy cast rods hurt reliability and smoothness without really saving any meaningful amount of production units, and the factory needs forge works regardless. Realistically I could remove material from the rods, making them lighter and weaker, which doesn’t hurt anything as they’re currently twice as strong as they need to be. The closest I can get is lowing quality, which causes a drop in reliability even though all parts are still well within their ratings.
Well, you are correct! But, what you propose would mean a rewrite of a core gameplay mechanic that has been locked down. Feature creep is dangerous and not something we allow unless absolutely necessary or super simple to implement and not affecting balance. That is not the case here.