I’ve had engineers that worked for me who REFUSED to accept that they might be wrong and refused to listen to any alternative. They didn’t work for me for long. That kind of inflexibility is unacceptable.
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This does not account for the fact that with a narrower tire, there is less surface to tug / tramline it side to side.
Not in any car with wider tires I’ve driven. Unless that 6 inch wide tire has more power steering applied to it.
Read this conversation on ‘Automotive Forums’ from some years ago. What was said, about straight-line stability, might surprise you:
Do Some Tires Have Better Straight-line Stability? - Car Forums and Automotive Chat
Thank you. Pretty much what I expected except the acceleration runs. I didn’t expect much difference.
Did you even read the table? Acceleration was best with the narrow tires. Oy vey!
Hopefully the right lane.
Of course. I drive German! Chris von KRETPinberg! 
Where do you see numbers for straight line stability in the Car and Driver table? I can’t find any.
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It’s not something that was routinely measured.
You just feel it. And frankly I don’t care if straight line stability is not a priority for anyone else here.
Please elaborate on each listed. This will be informative. Thanks.
Each listed what? I’m not sure I’m following you.
1/2 way there…
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Yes it does account for that. Suspension design generally has a larger effect on tramlining than tires.
I’ve driven many more cars than you have. As many as 25 in a single day in competitive evaluations.
Posted by random people with unknown qualifications.
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Your opinions on the above.
Hey I’m working on it. 
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All sites that are evaluating an existing car with standard width or wider tires. None of these sites altered the suspension design to minimize or eliminate tramlining. They only alter the alignment settings within the manufacturers allowances to effect a given chosen tire.
I suppose increasing Caster angle could overcome the tramlining experienced with wider wheels and tires.
And it’s not even an oil thread. We’re widening our horizons. 
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My current Mustang has 30mm wider 40 series tires (285/40/18) and 3 inch wider wheels (11 inch) than factory. That required me to move the front wheels outboard with spacers so the tires would not rub on the struts. So added positive scrub radius.
I also run - 2.12 degrees camber and added 0.5 degrees caster (factory was 7 degrees!). I used to run a small amount of toe-out (0.03 degrees) but I found the car’s on-center feel and tramlining to be greatly reduced changing to 0.02 degrees toe-in. Just alignment adjustments to compensate for me screwing up Ford’s good front suspension design work.
Compare that to my wife’s bone-stock Audi A4 Quattro with its 255/40/18 tires all around. Pretty large tires for a small sedan. This car tracks straighter and handles better than anything I’ve owned before. Power down does not introduce torque steer. Not even on the FWD version we test drove. This was true of the Continental tires it had when we bought it used and the Michelins we have on it now.
Why is this car better? It has 4 control arms each with its own ball joint at each front corner. 2 upper ball joints and 2 lower. This gives virtual upper and lower pivot points for the steering. Steering axis inclination can be much more upright than a strut car and positioned anywhere desired for caster trail and scrub radius as well as manage the gains for each. The SAI line can run right through the CV joint so steering does not introduce torque steer. The camber and caster gain can be optimized so that road feedback won’t introduce wander.
The car has electric steering too so no telling what kind of damping tricks Audi added to the control algorithm.
The point I’m trying to make is; Good suspension design will mitigate the negative effects of wide low profile tires. Alignment can help a lot but the bigger lever is suspension design.
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I worked with a few PhDs with PCs that argued their models were correct even when actual test data proved them wrong! 
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