Since none of us have driven any cars in the game, let's try a new test of physics. Find a car you drive in daily life, and run it in GT4 on a track you're comfortable with using road speeds (~40-120 KM/h), and try some basic maeuvers (i.e. shoulder drop off, eased braking, for those who drive stick, shift at ~3-4000 RPM, sudden braking, apply the emergency brake, etc.). See how it works. If the physics are good, you should've just had a YD of C style test for both car and driver.
Ummm... I actually own the same corvette I drive in the game. And I live an hour and a half from Laguna Seca... and also about an hour and a half from Infineon.

I can't speak for every car and every track in GT, but I can say that having driven the real thing and virtual thing back to back... the simulation of my car on the local tracks I've been to is pretty damn good. Good enough that I use it to practice for RL events rather extensively.
for the people that are "preaching" that the physics are real, and the comaprison to real life drivers is so close...I have a couple points....a few really. Here goes my rant....
1. the clkgtr flipping at lemans....can't replicate that in the game. real physics?
I've got cars into conditions where they tried to flip over in the game, but were restrained by the angle limits. Your right that there is an invisible force that keeps you from going all the way over. But... ummm... that only comes into play during an actual flip. Not a very important limitation, methinks (except it spoils some crash footage...)
2. you can't break the rear wheels lose on any car and redline the engine mid-corner and the car just stays straight. it doesn't happen. You would be looking at the guy behind you then you'd get a long walk back to the pits.
(Assuming that you're smart enough to know to turn off the driving aids...)
GT4 puts Sports Medium tires on most of the cars by default. Sports Medium tires are not a simulation of street tires. These simulate DOT legal racing tires.
Breaking these kinds of tires loose is _much_ harder than any tire you have ever driven on in RL.
Also... your virtual driver controls the clutch. And he never 'pops it'. He's super smooth. So you won't jerk the tires free by storing up a burst in your flywheel.
No, I would say you have it exactly backwards. In GT4, tires actually break loose under throttle while going in a straight line a little more easily than their RL counterparts do. Particularly at low speeds.
3. the whole in-car camera looking like you playing the game. Do you really think driving the real cars around the track, and being able to replicate that time in the game is solid proof that this game is so brutally realistic?
I agree with you there. Comparing lap times doesn't really prove anything. All the developer would have to do is scale the performance of the cars to make them match the RL lap times. They wouldn't have to tweak/change/improve the physics engine at all to make such an adjustment.
However... producing very similar lap times to RL is a good start.
4. just because a driver says "its pretty realistic" isn't gospel. I was around when an indycar driver i know first raced "indianapolis 500" for PC. he said "yeah, its pretty realistic." and that was back in like 94, so i'm sure Gt4's physics are better. I have more along these lines...
I don't think anyone is claiming that its not possible for there to be better physics than GT4. We can assume, for instance, that GT5 will probably be even closer to perfect realism (unless PD gives into the pressure and just decides to go arcadey like everyone else since that's what most players seem to actually want).
I am making the claim that GT4 has a level of realism good enough that I can practice with it for RL events. And not only that... but I have learned reflexes from practicing in the game that have saved me from losing the RL car and going for a spin or even a crash.
So my point is... at its current state, it is good enough to function as a viable simulator for the real thing. Practice in the game does translate into the real world.
And that implies a significant degree of realism.
5. and if the physics are so real....have joe video game player go out and try to come close to his times in a real car he reaches on this game. GOOD LUCK
Done.
The other hilarious thing is the sound, the Minolta sounds like it has a terminal misfire when you get to high RPM, thats how nicely made the game is, they dont even give a crap about the final detailing like this. Poor.
I agree 100%. Most of the engine sounds in GT4 sound aweful and totally unrealistic. While my simulated vette may perform much like the real thing, it doesn't sound like a V8 at all... much less a corvette V8. The real car makes this amazing throaty deep growl... where the virtual version of it sounds like a whiny little four banger.
OF COURSE GTR will have better physics
Greater computing power does not mean it will have more accurate physics. It does mean that it is potentially capable of modelling finer details thereby producing a more accurate simulation of the real world. But that doesn't mean that any such advantage is necessarily realized.
However, if we were to take GT4's Lister, and compare it to GTR's Lister, the difference in physics is night and day. Even with no driving assists, GT4's Lister is very easy to drive around Nurburgring, with little caution of steering input. If you try to enter corners at similar speeds in a Lister in GTR like you would in GT4, you're going off.
Harder to drive != More realistic
It seems to me that some of these games have taken the attitude that the harder to drive it is, the more realistic players will assume it to be. But that may not be the case at all. Engineers spend a lot of time trying to make the RL cars feel good and predictable to the driver. A lot of times, even in racing, you will set up the car to be a little easier to drive even at the expense of speed... cuz it just won't due to fall off the track every time you slip up a little. The driver is human, not a machine.
Nope. Simulations can _easily_ be more difficult to control than the real thing. Heck, one of the Enthusia reviews I read said that if rear wheel drive cars were as difficult to drive in real life as they were in the game, nobody would ever buy one.
Anyway... as for the realism of the Group C cars... I've never driven one in RL, so I can't say how accurate the game models them (and neither can any of you). I'd make a guess that it doesn't simulate them as well as it does more common street cars... for the very reason that the folks at PD will never have driven a Group C car in RL either.
However, I have no reason to believe that the level of stick in those cars is unrealistic. Getting them to pull the same lateral G's as in RL is just a matter of looking it up. And yeah... those cars generate such tremendous levels of downforce that they really do seem to defy the laws of physics (even though they don't actually... of course). But that actually is realistic. These cars are that fast (more or less). Now as for 'feel'? I don't know. It seems believable enough to me. But that's essentually just a guess as to what a real one might feel like.
- Skant