So I see a lot of incorrect recommendations for setting tire pressure. I found this info the other day 'n I definitely noticed the vehicles becoming more nimble once I started tuning to these numbers. Especially rear wheel drive cars. They grip harder, launch much cleaner, and don’t slide around so much when cornering. There’s a chart on this site that I use to tune all my tires. Essentially drive the car around 'till the tires are hot and adjust accordingly based on the weight of the vehicle. For instance a car that weighs more than 3000 lb should be running 40 PSI hot pressure.
As far as I’ve been able to tell over the years, there is no difference in optimal pressure between different tires in the Forza games for road courses. Tires start to round a little as they go over 34psi or so, with a slightly decreasing contact patch from rounding as you get further up from there.
That’s definitely not what I’ve seen since I started taking full stock cars and only tuning the tires. Setting them based on vehicle weight has definitely made them more nimble, launch better ( much less burn out / wheel spin time ), and stop quicker. I definitely recommend looking into it a bit more.
A stiffer tire is definitely more responsive - in game or reality. It just doesn’t necessarily have more grip, because it has a smaller contact patch and that patch is consistent through FH4 as far as I’ve seen. I tune everything, not just the tire, though. If the tire overheats the center compared to the sides, it’s overinflated and not using its full contact patch. So far, that’s been for any road car going over ~34lbs. If you can show me another car that doesn’t round at something over that, I’d be happy to test it.
I never tested based on weight but on Forza tires have different stiffness race tires are a lot stiffer than street or sport because this you will use higher pressure on street/sport tires to make stiffer AWD use high pressure but RWD/FWD use less pressure, less pressure less agility but RWD/FWD have high agility they dont need high pressure(if we remove AWD swaps theres a small possibility of RWD/FWD be better than AWD)
I definitely get more grip in a RWD using the method I mentioned. Prior to setting my tires this way they felt very unresponsive and launched much worse. Give it a shot. See how it treats you.
The best temperature for tires has to do with the rubber compound and how it reacts with the surface. Friction happens at the molecular level. In F7 it was roughly 180/200/220F max for stock/street/race. IDK if FH4 used different math.