I know the first release is just getting the models in game and it uses other physics. Just want to add more information for later on. The steering in the mod felt very light. Even with 100% ffb, which I rarely use, The car 'felt' very light and nimble. By the 70's, the tires Firestone & Goodyear produced were HUGE. 15 or 16 inches wide in the front and 19ish inches for the rears. No power steering so especially at low speed corners, the effort to turn those cars must have been extreme. Taking a look at the drivers of the day, very few resembled the Wee Scot Jackie Stewart. Many like Denny Hulme were truck driver sized, stocky, muscular etc. Today's F1 jockeys would probably slide around the cockpit due to the size most cockpits were to accommodate the larger bodied boys.
I can't attest to many of the Interseries/European cars, perhaps they WERE light and easy to drive, certainly the early 2.0L Climax & Ferrari might have been. But as this project progresses, I HOPE we get a good approximation of the size & weight of these cars. The '73 Penske/Donohue Porsche was probably close to 2000lbs when fueled for a race.