Tire pressures

My chevelle lists both hot and cold tire inflation recommendations, but it’s for the 4ply tires. 24/24 and 29/29 F/R hot then cold. But also lists continuous loads at maximum(over 5 passengers, etc) at 26/30 and 31/35. I dunno why they’d want pressures so low, but then gain, tire technology has changed in the last 42 years.

Again it depends on the type of car and how the car is set up, but if you try that in an early 911 …
You are changing the parameters again. That 911 was a mid-engine car with nearly 50-50 weight distribution. A 50-50 car with identical camber will be neutral, no oversteer, no understeer, until acceleration, either positive or negative, is applied.

… (don’t ask me how I know) … (don’t ask about that either) …
Nah, I’m asking how you know. Can you explain the physics of how your Porche 911 handles? I’ve never been lucky enough to drive one.

Actually, a 911 is rear engine with a little more weight on the rear wheels than the front, but I agree with your statement that the are designed to be very close to neutral, which is why you can use the throttle to transition from understeer to oversteer. I haven’t driven a 911 on a track in many years, but the old ones were a little “twitchy” in the corners. People who know how to drive them far better than I were able to take advantage of the handling characteristics and get through corners very quickly. Basically, the acceleration or deceleration would transfer enough weight to the front or rear to change the handling characteristics. The preferred technique was to brake in a straight line before the corner, then power through the corner using both the steering and throttle to keep the car on the correct line (sudden changes in throttle or steering inputs were to be avoided).

If you let off the throttle quickly in a corner, some weight would transfer to the front and the rear would tend to get loose very rapidly. This transfer from understeer to oversteer could happen very quickly and it was very hard to “catch” the rear end if it broke loose. The last time I drove a 911 on a track (this one belonged to a friend), I ended up going backwards through the grass after spinning a couple of times (fortunately it stopped before hitting the fence). My understanding is that the newer ones are much more forgiving, but I’ve never driven one. Check out this guy’s inside front wheel.

Of course, none of this has much to do with daily street driving. On the street, I normally run my tire pressure a little (2-4 psi) above the manufacturer’s recommendations, but I do keep the relative front/rear pressure difference close to the recommended difference. I’m still not sure why VW has the rear pressure so much higher than the front, but I would stay close to the recommended values unless I had good reason not to.

Check out this guy’s inside front wheel.

I tried to attach a photo, but it didn’t work?