I will need to get new tires in the next month or so. It came with 245/75/16 and wanted to know if I could put a larger tire on my 99 4X4. Is there an advantage to bigger tires? will they last any longer?

 

Given that you said "winter" and I assume snow and possibly ice may be encountered, usually the more rubber you can get on the road the better.

However larger tires if taken overboard can scrub on your wheel-wells, cause an error in your speedometer, and IF you want to create a flat footprint, you'll have to reduce the pressure.

Then, given that the pressure is lower, you may get a side to side wobble, which will reduce you cornering control, and of course lower pressures do not permit maximum loading of the tire.

The reason why all this occurs is, that the tire width is wider than the rim width, causing the sidewalls of the tire not to be/run vertical.

IOW: The Tread Width and the Rim Width should be the same for best performance.
And when this is done, one can maintain higher pressures in the Tires, which improve Mileage, Cornering, Braking, Loading Ability and Longevity.

People do this all the time, and most never have/realize these problems. But, you might consider buying some inexpensive "winter" Rims which are correct for your wider tire choice, mounting some good Snow/Ice's on them, and just switching out for winter.

One other thing. It's hard to get a Tire which does both (hi-way/snow) well. Good hi-way tires are flat, smooth, and have good traction on pavement. When you start putting a tread on them where they will grip in Snow or Ice, when used on pavement, they're noisy and vibrate, which some don't mind. Also, when you start grooving/separating the tread to grip in Snow, you loose traction and control on dry pavement.

I've always been a proponent of not trying to make one tire do two jobs, and had a separate winter set of rims and tires.

My winter set were big and ugly, BUT, they got me home !

 

ok thanks for that info on the rim width. These will be mounted on the original (6.5" rims?)
and I do have another set of rims for the summer.
Also what about these studdable snow tires like "Blizzaks" Artic Ice or "Winterforce I wonder if anyone has used these and for pushing some snow.??

 

I've not used Studded Tires, mainly because they were not permitted where I lived. You should check with your local authority about a similar restriction. Chains were the "serious" option, which I used several times though the winter seasons.

The 245/75/16 generally run just over 7" wide, and are within the recommended usage on a 6.5" rim.