With a 4WD truck do you have to replace all tires together, or can you just do the front or the back?

awwwww sales men will tell you anything... but I really can't say without looking at your tires , I always just changed my tires on my Toyota 4wheel drive Truck in sets, rotating with the spare , so that way I would only have to get 1 tier, used the spare full sized tire, move the fronts to the rears , and used the poopy tire for the spare , , but I watched the wear on the tires , I always used the best tires on the rear for traction, and changed them in sets, fronts to fronts, rears to rears . went thru 4 sets of 4 tires over 550,000 on my Toyota truck that way. but you HAVE to watch the wear on those tires worn the worst, and if they get bald (showing belts) especially on the front, COULD hydroplane easy and steering could/can be tricky in wet conditions , and you COULD loose control of steering because of that , I just drove slower . as always tho, MOST important thing, ( I usually do it every 2nd time I get gas) Proper inflation in a tile gives best mileage, and cold/heat deflates tire pressure , especially when big Temp changes occur, like @ where I was , in winter/spring 20 below at night then during day time went up to 60 and 70s ( a 90 degree change in temps= bad for tire inflation/deflation. ) to check max /min tire pressures , its listed on the side of that tire ... and it most likely is the MOST important thing easily checked for best mileage , but the LEAST checked thing anyone does, and then balancing the tire is good also, by just having 1 pound of pressure missing from 1 tire catyywampuses the car/truck. ... all tires should have all the same amount of air pressure in them, it keeps car/truck. level, in balance, its a thing of balance, unbalanced tires give really bad gas mileage and or wear really fast, and usually people really do not think of their tires, but when buying tires , you should THINK carefully ... should you get the cheapo tire for 100 bucks with a rated 40,000 mile warranty... or spend 150 bucks for the better tire that is rated 80,000 miles , that Extra 50 bucks goes twice as far, and you don't have to get tire as often, and as ALWAYS , I tell people, do you look at your gas gauge when you gas tank is getting low? and they ALWAYS answer yes , then I say, did you check the tire gauge too? and they say NOOOO, then I say well you fill up your gas tank when it low, want to save gas... check the air pressure on you tires too, proper inflation give proper balance, and just ONE pound of air pressure off ONE tire , will cost you 5 gallons of gas , and gas costs WHAT??? 4 dollars a gallon here , I don't know about you, but my Toyota 4 wheel drive truck got 32 miles to the gallon, I checked my mileage EVERY Tank fill up, and if it DIDN'T get 32 miles to the gallon, I knew something wasn't right, and it usually was the air pressure in one ,or another of the tires that was off... buy ONE pound ,,, and there are 4 tires to check, and people... will be people, they get in their car/truck and every ones ina hurry, me I walked around my truck... every time BEFORE I get in it and look at my tires, it one is off, well go fill it up, but people don't do that And a tire gets low... constantly, because of Temperature changes ... fill em up, or keep filling yer tank,5 mile of mileage = per year 4000 miles you COULD have driven... free per year

They're just trying to sell more tires. No, of course not. Put your new tires on back, and put your two best used tires on the front.

Putting your new tires on the back might seem a bit silly, but there isn't as much weight back there. So if you're driving in the rain, a better back tire will keep you from hydroplaning in the rear end, while the extra weight will compensate in the front.

^^ Fun fact.

awd system cars I would say yes to recommended, but 4x4 trucks no most the time your in 2wd . I would only replace all of them if they all have bad to no tread otherwise id keep the best 2 and replace the other 2 . when I needed to get a new tire on my 4x4 pickup I just replaced the rear 2 (mainly because I cant afford the 300 a tire) and its doing fine

you don't have to - but you will get better performance from your truck if you do