Mixing tyre sizes between front and back

[duffbeer911]

Hey,
I had to get two tyres replaced on my 4runner and see that the guys have put bigger tyres on the front. So now I have:

FRONT: 265/75 R16 (new)
BACK: 275/70 R16 (old)

I'm in Sierra Leone so we don't get a big choice - I am planning on changing the back ones when I can find some new 265/75 to match the front. But in the meantime is it ok to drive with different sizes on the front and back? And should I move the bigger tyres to the back (even though their tread is not as good)?

thanks

 

[white_n_slow]

You should be OK if you keep it in 2wd. I don't know how feasible that is where you live.

:edit: after checking the tire size calculator, that is a 31.6" diameter versus a 31.2" diameter, which is only a 1% difference. Generally speaking you can have up to 3% difference before you start putting mechanical strain on your transfer case. So I think you should be OK You may want to measure the actual diameter with a measuring tape since tire sizes vary by manufacturer, wear, etc.

 

[BlackCat914]

Yes, it's ok to drive as long as the matching size tires stay on the same axle.

 

[Grenvilleter]

If you never use 4WD, you will be ok.
If it were me, I'd put the new tires on the back where there won't be as much wear until you can find another pair to replace your old ones.

You cannot have the front differential turning at a different rpm than your rear diff without causing problems and that is what 2 different diameter tires will do.

In an extreme emergency, mired to the axles in mud, go ahead and use the 4WD to get out but DO NOT drive any more than say...10-20 feet with mismatched tire sizes between front and rear.

 

[duffbeer911]

hmmm, ok ... so I often do need to use 4wd though I can probably avoid going offroad for a couple of weeks until I find some matching tyres.

Just looking around the forums about different size tyres and people mention the bigger tyres will increase fuel consumption .... do you think that is something I'd notice considering I rarely go over 60km/h and 50% time on dirt roads.

 

[BlackCat914]

with a VERY minimal size difference, you'll be absolutely ok to use 4x4 whenever you need to. I am 130,000% sure you won't have a single issue in relation to tire size.

 

[xhimsa12x]

You will totally be fine, however I would move the bigger tires to the rear expecially since it's RWD primarily. Lots of people including me have race cars that have bigger tires in the rear on RWD applications. I have same size on my 4runner but wouldn't hesitate to put a different size from front to back if I had to as long as they are on same axle.

 

[duffbeer911]

ok thanks. Can you explain to me what the advantage is of having larger tyres on the back?

 

[JayRolla]

I dont agree with the statement that you will be fine in 4wd with different tire sizes. Ive seen people kill xcase just from tires being underflated in the front or rear on an AWD Mitsubishi. Our 4runners dont stay locked in 4wd all the time so its not as much of a deal. But you will cause wear and tear on the tcase when in 4wd. It can cause the xcase to bind up when turning. Not a good idea at all. People kill there sti's, evo, dsm awd xcases all the time when some kid runs different tires or rim size to make there car look cool.

 

[JamesDean91]

Cars are weak.. our yotas have I'd say 40% stronger components then any of these cars... back in the day when my father rock crawled and mud dragged people would put 4.11 rear 4.10 front or vise versa don't remember but they came out of stock ford 60s

 

[BlackCat914]

I dont agree with the statement that you will be fine in 4wd with different tire sizes. Ive seen people kill xcase just from tires being underflated in the front or rear on an AWD Mitsubishi. Our 4runners dont stay locked in 4wd all the time so its not as much of a deal. But you will cause wear and tear on the tcase when in 4wd. It can cause the xcase to bind up when turning. Not a good idea at all. People kill there sti's, evo, dsm awd xcases all the time when some kid runs different tires or rim size to make there car look cool.

why are we comparing AWD with LSD's to a 4runner? Plus, he's talking about using 4x4 in dirt and mud, not while on dry pavement.

plus, a 265/75 is nearly identical in sidewall height to a 275/70 anyways.

 

[JayRolla]

why are we comparing AWD with LSD's to a 4runner? Plus, he's talking about using 4x4 in dirt and mud, not while on dry pavement.

plus, a 265/75 is nearly identical in sidewall height to a 275/70 anyways.

Your right I was talking about AWD with visous LSD's and with the tires being that close to the same size he will most likely be fine since hes not running in AWD all the time.

 

[duffbeer911]

ok thanks for the advice ... I will still try and get a another pair to match as soon as possible. Cheers

 

[BrianSD_42]

I have run that same setup for a least 2 years now and have had no issues in 2WD or 4WD.

My truck is a 97 and does not have AWD.

 

[sportscarfan]

I agree that you are totally fine with those sizes - I'd guess that you never use 4wd on dry pavement (where you'd have the most potential for damage with the greatest amount of traction). In general, I only use 4wd on surfaces where the tires can slip when necessary (wet road, dirt, snow, trail...).
It might take a while for the 275/70's wear out in the back...don't worry about it.