One of the things that occurred to me when I was trying to design my own contest was that the in-game stats are very well suited to describing consumer impressions of a new car. People should perceive active safety - drivability - as an essential component of automotive safety, but when a large part of the popularity of SUVs was that they were seen as safer in spite of their drivability issues, you have to separate the former from the latter to model correctly. I personally think a fancy little high-revving four-cylinder engine is a lot cooler than a big simple V8 making the same power, but that just means I care more about Sportiness than Prestige. Even things like Reliability being a single, arbitrary number make sense - the customer is working off stuff like Consumer Reports testing, and doesn’t know the Mean Time To Failure of any of the components.
The main area where some balancing of wheel-spin might be required is with lower powered cars.
I have two examples based on cars I owned, both end up getting around 20% wheel-spin, even though both of those only get some wheel spin at the very beginning of the first gear IRL.
The first one is a Geo Metro, with a 75hp engine, 155 medium compound tires, a first gear that red-lines at around 50 and a second gear that red-lines at around 80.
The second one is a slightly less accurate Chevy Aveo, with around 95hp, 185 medium compound tires and slightly longer gearing than the real life car.
The penalty to drive ability ends up at around -5%, which is definitively non-negligible, especially if we consider that its going to be a big factor in the demographics that usually buy those types of cars.
That is an interesting observation, TrackpadUser. This probably has more to do with how tires are balanced currently. Shit tires need more longitudinal grip and less lateral grip (i.e. more sane skidpad values). It is balanced that way currently to make track times reasonable, but as soon as we have Martin’s new track calculations in the game we will be able to rebalance the tires without making track times ridiculous! 
I think there are some issues with AWD vs. RWD in the game.
AWD essentially eliminates ALL wheel spin on my cars. I just built a reasonable V8 using the modern coupe (looks like a Corvette sorta) with good balance for a F/R car (53/47). Using the same motor, a 5.0L, tuned to 425hp/375tq, an AWD 6 speed has ~6% wheelspin, while a RWD has ~64% wheelspin. The car is around 1250 kilos, so somewhat lightweight, but not extremely so. With the AWD, you lose usability for 1st gear, while with the RWD setup you lose 1st-3rd gear. I know V8’s tend to spin tires easily, but not THIS easily, and AWD magically makes it all go away? I just think the difference between the two should not be so dramatic. In fact, the magical AWD reduced the much more powerful 6.0L (499hp/445tq) V8 from 68% to 10% in the same car, at around 1350 kilos. Granted, the bigger engine upset the car balance to 56/44, which is expected.
Both of these cars are using 245/40-18 tires. Sure, I could throw some beefy 335’s on all four corners, but this is not a realistic solution for a moderately powered car. This kind of tire is reserved for supercar power-to-weight, which I am nowhere near.
With both cars, changing gearing for the RWD setup made only minimal improvements to wheelspin. Best I could gain was 45% wheelspin with the 5.0L car. Thoughts?
400hp is definitively not moderately powered 
That’s the kind of power output you get with an LS2.
As for the RWD vs AWD, it might need some rebalancing, but AWD truly is somewhat OP IRL.
You are pretty much doubling the amount of surface you are transiting the power to.
Just to make it absolutely clear, a Corvette Stingray, which was your basis, it seems, uses 285/35 R19 rear tires and 245 fronts. Also, RWD cars with more than 250 hp or so, usually have wider tires on the rear.
Well look at the last gen dodge charger, it’s ~340hp 5.7 hemi could smoke tire in regular r/t trim but when you bumped up to r/t awd the tire spin pretty much disappeared.
[quote=“TrackpadUser”]400hp is definitively not moderately powered That’s the kind of power output you get with an LS2.
As for the RWD vs AWD, it might need some rebalancing, but AWD truly is somewhat OP IRL.
You are pretty much doubling the amount of surface you are transiting the power to.[/quote]
Well, my argument is it needs rebalancing. The 6.0L in the second example actually was an LS2, with 499hp. The 5.0L was a modernized L99 (305) with 425hp. The car was being built for the MRCSR Time Trials, but since it also will not seem to save beyond the initial build-through, it was scrapped.
There will be rebalancing of tire grip, that is the only thing that can and will be rebalanced as the rest is pure physics. If you don’t like physics that is not the problem of the game. 
My Infiniti M35s has 245/45/r18 high performance all seasons on it. Being all season, I assume this should be equivalent to a fairly high quality mid level tire? I made it +9 quality, which is likely a little over optimistic.
Unless it’s running on standing water, it will never wheelspin in second gear. If what you say is true, this should lead to 0% wheelspin penalty, since no wheelspin occurs in gear 2+, and this is by no means what results in game. This is with an accurate 303 hp VQ35HR, a 7 speed with first gear ending at low 30 mph’s and second at just over 55. It gives me a 36.2% wheelspin, in a 3800 pound car with an lsd, an automatic transmission with fairly long gear ratios, with a rear multilink setup that should keep all the tire on the ground. I don’t believe that that is the way the penalty occurs then.
However, if I look at the graph, that is fairly accurate. As soon as second gear comes around, the car stops wheelspinning. I don’t mind having a wheelspin penalty in this car, in the rain it deserves it, spinning in second easily. But it most certainly is not based upon gear 2+, in normal conditions, when no wheelspin at all occurs in that range, and there is a reasonable gap between the tire grip and the engine output.
Also, with traction control it has a -3% penalty to drivability, but I could stomp it in any gear at any speed and not have any wheelspin occur. The only way to have anything happen is to have it in first or second gear, turning around a hard corner, with a lot of water on the ground, and to floor it. In which case, the rear end will rotate a little bit before coming back into line.
Thanks for pointing that out gt1cooper, I’ll check if there is a bug in the calculations or in the displaying of results.
The same thing seems to be happening with the two cars I mentioned earlier. There is no wheelspin outside of 1st gear according to the graph yet they get a penality.
Alright, I looked into the matter and found that there were two issues. The calculations were looking at what time is spent in the first ten seconds of acceleration spent potentially spinning the wheels independent of what gear you are in.
I have now changed the calculations to be more solid. Now the time spent in each gear during the acceleration run is tracked, as well as the time in each gear that you could potentially spin the wheels.
I then loop over the gears, but for the first gear I only take half the wheelSpinFraction value (but not zero, so that you can’t really cheat by super long first gears).
wheelSpinFraction = wheelSpinFraction + timeSpinningGear / timeGear***
after all gears are summed: wheelSpinFraction = wheelSpinFraction/numberOfGearsUsed
The drivability multiplier then is calculated as factorWheelSpin = (1 - wheelSpinFraction) ^ 0.25
The second issue is that the graph showing the calculations seems to be bugged and doesn’t show the actual amount of potential wheelspin. I will have to investigate that one with Cas.*