Hello,
I have had many nissan or infinity vehicle's
So i thought when i came across this 2015 qx50 journey awd which looked like new with no accidents i should now is the time to replace my 2007 maxima.
I love this new car and power but it has one terrible problem. It tramlines real bad, i assumed it was an alignment because front tires were worn on side of tires, so i went to infinity and had 4 wheel alignment. Damn the problem continued, so researched and webb said it's the tires (bridgestone turanza el42 245/45-19)
I then replaced with the maxima tires (firestone firehawk 245/45-18) and then went for a little ride and damn if it still tramlined bad.
Wife loves the car but lets me do driving because it is hard for her to hold strait on the highway.
So now I'm not sure what to do. Is this a unfixable problem with this car?

Nothing is unfixable but the dealership is the last place I'd ask as they're barely adequate to change the oil and they charge a lot more than independent garages. If the wheels are aligned and you changed the tires you need to have a qualified shop check the steering, brakes and suspension. Any one, or a combination, of these components could be the culprit. My 2014 QX50 drives at all speeds like it's on rails regardless of the road.

I have gone to a couple independent alignment places and they said all they could not do anything except to set it to factory settings, and if dealer already did that then nothing else would change.

When you changed the wheels do you mean the tires or the entire wheel: If the rim is out of true changing tires will not help but that can easily be disproved by rotating the back and front wheels. Also, if yours is an AWD there could be an issue with the front power train causing the car to pull to one side. Have you test-driven the car with the traction control turned off? And ensure that the "snow-mode" is off.

Replaced the stock 19" rim and tire, with 18" rim and tire, the replacement rims were off my maxima which drove strait and true.
I haven't tried turning anything off or one.
Winter mode is off. The car is awd and drives ok until you arrive on highway where these worn indents of many cars worn the road down. When car gets to these it will sharply run either left or right depending on what side of the grove in blacktop it is hitting