4 X 4 Tire Question

[ken1989]

Have a 2016 Ram 4X4, tires have 50% left. One tire has a deep cut but not leaking. I was going to replace the bad tire with spare tire which is identical but new. Would you put the new tire on the front or rear axle? Thanks!

[fordtruckin]

Originally Posted by ken1989

Have a 2016 Ram 4X4, tires have 50% left. One tire has a deep cut but not leaking. I was going to replace the bad tire with spare tire which is identical but new. Would you put the new tire on the front or rear axle? Thanks!

I’d never replace one tire, always replace in pairs on the same axle.

[nebcfarmer]

And if you still decide to just replace one tire, put it on the front.

[204ruger]

It is recommended to replace all four if your truck has 4x4 auto because it is hard on transfer cases if the tire tread depths will be substantially different.
But pairs is better than just one.

[Unregistered user]

Change all 4, cheaper in the long run.

[elkhunter11]

If I had to change only one tire, it would go on the front, because the front tires only see power when 4x4 is engaged. That being said, I would likely change all four. I like to purchase from companies like Kal Tire, and Fountain Tire for their road hazard warranty, I had a sidewall puncture on a tire, and I received four new tires for 50% off, because the treadwear was measured at 50%.

[58thecat]

Originally Posted by Unregistered user

Change all 4, cheaper in the long run.

Its a dodge...nothing cheaper in the long run.....put the spare tire on the rear end....the one tire that hooks up does the pushing.....

[Tfng]

Is the cut in the tread or the sidewall?

If the cut is no deeper than the tread I’d drive it and never worry about it. If the cut goes below the tread I’d check to see if it has exposed cords in which case the tire is garbage. You’d have to get right in there with a prying device and a good light to see how deep the cut really is.

If money is no object I’d put 4 tires on it.

If money is tight I’d buy two tires and install them on the rear but not use 4x4 in high traction situations over long distance.

If you’re broke buy a used tire of the same size and wear.

Significantly mismatched tires on the rear will destroy your diff in short order.

[Dean2]

Even with a deep lug tire, tread depth new is about 12/32 of an inch. Even if the other tires are half worn we are talking a difference of 6/32 of an inch. The new tire will have at most 1.2" larger circumference and a 12/32 larger diameter than a 50% worn tire. That isn't going to screw up anything.

Personally I prefer replacing tires in at least pairs but if money is tight I would do just the one and put it on the front but right rear works too.

[cody c]

best tires on the steering axle, unless you carry alot of weight, and rotate every second oil change.

[Tactical Lever]

I'd probably put it on the right rear. That's the tire that ends up breaking traction the most due to driveshaft torque. That will even it up a little.

I'd only worry about the small difference if your rear diff had an auto locker.

With the difference only being a couple sixteenths of an inch, it would be like making a turn every half mile. Or like driving a road with marginally more turns one way than the other.

[Tfng]

12/32=3/8

I’ve always used 1/4 inch as my guideline.

I did quickly and roughly without pen and paper calculate the difference to be 9 revolutions per mile assuming a 30” new tire.

That works out to 70 feet per mile.

Whether that matters or not is up for debate I guess.

[tirebob]

Different vehicles and different driveline systems all react differently to mismatched overall diameters/circumference of tires....

Generally speaking, on vehicles that operate primarily in 2wd (most 4x4 trucks are 2wd unless locked in 4x4), the traction wheels are you want them matched to a close degree. If it is not, it will not cause your vehicle to catastrophically fail or anything, but it will cause premature wear of the related components over a longer period of time. Not a big deal in the shorter term, but long term it could cause you to spend more money in other areas sooner than maybe you would have. Mismatching on the front of a rwd is best for the wearable components, but then you may be fighting a constant pull on the steering. Not really damaging but potentially annoying.

Now on a full time AWD it is not ideal for sure to have mismatched diameters because those system redistribute power around to maximize traction in corners or if the vehicle detects slipping etc, so with the improper diameters it will be potentially tricked into misdistributing power around because of the different speeds at which those tires will be turning which in turn will mess with the optimised handling and also prematurely wear related components. Again, not a huge issue in the sort term, but possibly expensive wear long term. On awd vehicles, you want to keep the tires on the same axles very, very close but front to back can be a bit more variance for sure.

Again, some vehicles tolerances are very tight while some can handle a fair bit more variance. My point is there is not hard and fast rule. On the OP's truck with 50% wear, I would absolutely recommend a pair for sure, but if it is not locked in 4x4 for any real long and regular use I would say he doesnt need four, but if he does use 4wd a lot on pavement I would be doing four if I owned it. Locked in 4wd on dirt etc though it isn't near the issue.

[CaberTosser]

For the OP I would stick to having the same tires across each axle at minimum. I have previously played Scottish cheapskate by rotating a full size spare into the mix and relegating a partly-worn tire into the spare position so that only one tire had to be purchased to get two equal tires across an axle, in that case I put them both on the rear as they had greater wear than the fronts.


I was talking with the lead mechanic at my dealership about tire sizes as it applies to my specific vehicle and its 4WD system, he noted that so long as they're within 2% between the front and rear axle they're OK (this being a Mercedes Sprinter 4x4 dually). I was inquiring about changing my tire sizes but I have a weird compulsion about getting creative with my fronts by having a wider wheel and tire out front but maintaining the same revolutions per km in the differing front and rear sizes. It would be as simple as taking off the dually adapter hubs and running the 2500 wheels and keeping one hub adaptor in the van in case of a flat so that the spare could fit up front (of course the spare be on a dually wheel to match the rears). I want 50mm wider fronts and only 20mm wider rears from my rather skinny factory 215/85/16's. If I could get rears the same width but taller and the same revolutions per KM as the desired fronts that I want I would opt for those but there's no 95-series tire sidewall to get taller from an already 85-series sidewall.

[Dean2]

Originally Posted by tirebob

Different vehicles and different driveline systems all react differently to mismatched overall diameters/circumference of tires....

Generally speaking, on vehicles that operate primarily in 2wd (most 4x4 trucks are 2wd unless locked in 4x4), the traction wheels are you want them matched to a close degree. If it is not, it will not cause your vehicle to catastrophically fail or anything, but it will cause premature wear of the related components over a longer period of time. Not a big deal in the shorter term, but long term it could cause you to spend more money in other areas sooner than maybe you would have. Mismatching on the front of a rwd is best for the wearable components, but then you may be fighting a constant pull on the steering. Not really damaging but potentially annoying.

Now on a full time AWD it is not ideal for sure to have mismatched diameters because those system redistribute power around to maximize traction in corners or if the vehicle detects slipping etc, so with the improper diameters it will be potentially tricked into misdistributing power around because of the different speeds at which those tires will be turning which in turn will mess with the optimised handling and also prematurely wear related components. Again, not a huge issue in the sort term, but possibly expensive wear long term. On awd vehicles, you want to keep the tires on the same axles very, very close but front to back can be a bit more variance for sure.

Again, some vehicles tolerances are very tight while some can handle a fair bit more variance. My point is there is not hard and fast rule. On the OP's truck with 50% wear, I would absolutely recommend a pair for sure, but if it is not locked in 4x4 for any real long and regular use I would say he doesnt need four, but if he does use 4wd a lot on pavement I would be doing four if I owned it. Locked in 4wd on dirt etc though it isn't near the issue.

As Always a fully complete response to the question. The op may be running a pickup but the part about awd or full time 4X4 is really good info in case someone reading this doesn't have a plain pickup.

[Wes_G]

When you put the tires on originally did you buy the extra road hazard warranty?

When I did my truck tires I bought the extra warranty ($8 a tire) and when one tire failed I was a little ****ed when the tire shop told me they would not replace just one but had to do all 4 on my truck. Then they asked me if I had bought the road hazard warranty originally which I didn't even think about at the time and had to go back and found out that I did. I ended up with 4 new tires for the price of the environmental fee. Extra warranty is money well spent, saved me about $1200, and I totally forgot I even had it.

[ken1989]

I very much appreciate all recommendations. Will take it to a tire shop and install new tires all around. Thanks again!