Will highway tires give me better ride quality on my 1998 Tacoma, that currently have all terrain tires?

You will get a much better ride quality, better cornering, better traction in rain/snow/ice, but will lose the grip in mud and dirt, and might (not always but sometimes) get worse gas millage due to the fact that some A/T tires are very hard, which equally low resistance and better fuel millage. The best all around tire ive ever come across is the "Michelin LTX AT2". Its whats called an 80/20 tire. That means its built 80% for street and 20% for offroading, unlike most A/Ts which are 50/50. It gets great grip on pavement, a very smooth ride with no road noise, still has good grip in dirt, and has little "claws on the outer tread for traction in snow and mud. Any body who has a truck or SUV that is not used 100% for 4 wheeling should look into buying these tires when they go shopping. They are worth the $150 per tire. Ive had them for 35K now and they still look brand new. They have a 30,000 mile full replacement no questions asked warranty, and 80,000 pro-rated warranty. You cant beat them.

a softer ride ? yes but mileage may become a factor. all terrain is as stated. but if you don't do any through the dirt then you should get what you want. if you do highway driving a lot a higher rating tire may only improve the ride some. shop when you have time but watch the sales pitch. buying something you don't know about yourself ...sad.

What you want are pirelli scorpions if you can afford them. Liquid butter.

Tires arent going to make a difference in the ride one bit.. they may be quieter though and also help with mileage. its a truck, it will always ride like a truck unless you invest in a full air ride suspension.. you can get a good shock that will help some though, look into the rancho shocks..