The 156 saloon and sportwagon, and the GT are really the same thing, so no fundamental differences chassis wise. Comparing TS/JTS only, the weight difference is very small, less than the weight difference between a small driver and a large driver, so not worth worrying about. Bodyshell rigidity - I've not seen any figures that suggest one is better than another. The wagon shell may be stiffer? But who would ever notice the difference on a normal road car? Main difference in springs/dampers is between 'lusso' and 'veloce' but if you're only looking at selespeeds I think they're all veloce? And remember some wagons were fitted with self levelling rear suspension.
But given these are all old cars now, the main thing by far will be the state of the suspension - worn out bushes, ball joints, dampers, etc. And worse, possible silly mods by previous owners or cheap low quality replacement parts. Not to mention cheap tires. So really you need to drive the car to determine whether it's good or bad.
And if you want to beat the Passat, that's more down to the respective drivers skill than anything.
Thanks for the detailed answer sprint veloce. This would help a lot.
Pack names are different here; no Veloces or Lussos. Just Progression, Distinctive... So impossible to determine. AFAIK no self levelling suspensions either.
I'll replace the springs, dampers, bushings and all replaceable suspension parts if necessary. It's the car's inherent dynamics that worries me.
Let me put it this way: Fresh from factory with the same/comparable trim level, would a SW match the saloon in handling? How much difference, if any?
As for body rigidity, my assumption is SW would have lower numbers. Am I wrong? And higher centre of gravity would result in more body roll; but how much different from saloon again?
And about beating the Passat; I haven't been tested tested on track but being an engineer with some understanding of vehicle dynamics and complete faith in rules of physics, I like to think that I'm a more capable driver than average Joe. Or average Mehmet. Whatever.
I just wonder if 156's limits are higher than the Passat (which is a common sight on our roads).
EDIT: OK, found it.
That's 96000daNm/rad for Sportwagon, compared to 110000daNm/rad for saloon. Slightly higher than 147 5drs. With a good suspension, it should be negligible. So just need comments about how the higher center of gravity affects its dynamics and body roll.