Brake Fade seems a bit extreme on very light cars. Especially modern ones.

[Arya]

I'm working on something a little unusual, it's a very light car designed to achieve the best possible fuel efficiency - as of right now 1.8 L per 100KM.

And it's highlighting a problem that I was also having last night, on another very light car. Extreme brake fade. The only way I can get the message to clear, is by putting on enormous 275 front/250 rear brake discs with 70% racing brake pads. This is a big problem; that's collosal overkill for an 850 KG economy car. And it's adding a lot of unneccessary cost, weight, production units and more.

[Admiral Obvious]

What type of brake fade though? Sportiness fade will almost always be a thing unless you go overkill on the brake sizing.

[CBR JGWRR]

It's a road car, and a hyper-eco focused one at that, which necessarily means the brakes are not going to be used frequently (if at all, ideally - brake usage represents wasted fuel after all) - provided it will stop once or twice in quick succession it will be fine.

[Killrob]

You must be doing something really weird, I just tried to build a super-light eco car and without any optimization got 2.2L / 100 km running at a total car weight of 418 kg. Yes, that is half the weight of your car, but I'm running 160mm solid disk rotors front and rear and end up with brake fades of:
0.6% Drivability
1.3% Sportiness
1.6% Utility

So from that extreme case scenario I gather that everything is in order. You'll have to send us your car so that we can see what is causing your issue, as here all seems to be fine in my simple test case.

[Arya]

Originally posted by Killrob:

You must be doing something really weird

After experimenting some more, I can say beyond doubt this was a problem I caused and not an issue with the game.

First of all, I thought Brake Fade was a worse problem than it actually is. As you've both pointed out, a bit of fade is fine on a car like this. It's designed for commuting, and to sit at 60/100 KPH and just hum along sipping fuel. It doesn't need race brakes, a bit of fade is absolutely fine.

And secondly I found some design issues. I wasn't running any brake cooling. Because I was sleep-deprived and forgot to install it, like an absolute dummy.

I have another lightweight car to play with, a little family wagon that weighs ~ 890 KGs at it's most basic trim level. And which actually uses the same engine as my hypermiler. And it was running just fine with small brakes.

I then re-built the problem car, this time I had access to some newer tech and chose a Glued Aluminium frame with a Fibreglass body. And when this new version was finished, it didn't have any significant braking issues. And actually handled really nicely in Automation, better than I expected.