How much variation in tyre size is ok?

[Charles]

Hi Guys,

I am running 245/70/16 dueller 697s on the D2 which are around 50% worn. I also have 2 brand new mounted spares.

I have always kept to matched sets of 4, however; am about to head off on a trip in a couple of weeks and was thinking of putting the fresh tyres on front axle as they will be a bit smoother on bitumen.

Question is, can I get away with this or am I asking for trouble?

Cheers, Charles

[AllTerr]

Hi Guys,

I am running 245/70/16 dueller 697s on the D2 which are around 50% worn. I also have 2 brand new mounted spares.

I have always kept to matched sets of 4, however; am about to head off on a trip in a couple of weeks and was thinking of putting the fresh tyres on front axle as they will be a bit smoother on bitumen.

Question is, can I get away with this or am I asking for trouble?

Cheers, CharlesI've done it before on several different vehicles. As long as you keep them to the same axle, there should be no worries.

[Charles]

Cheers AllTerr

[trout1105]

If all your tyres are 50% worn I would strongly suggest that you replace them all if you are heading off on a trip, The last thing you need on a trip is tyre problems.
Older half worn tyres are OK for Town work But as they have usually also suffered some bruising/damage to their sidewalls as well as tread wear during their life on the truck they are susceptible to failure on extended trips.
I don't think that the small difference in the size of the new tyres will hurt the truck too much But why risk a blowout by not replacing the rear tyres as well.

[Charles]

Also a very good point Trout...

[weeds]

I like to keep four tyre with this same wear rate

If it was me I’d buy two new tyres, fresh ones on the front, two spares that are new on the rear and the best two 50%ers as spares.

[RobMichelle]

I agree with weeds 👍

[bee utey]

The rolling diameter of a tyre varies very little with tread wear. It's the length of the steel belts under the tread that determines the revs/km. Differences in tyre condition may affect your handling if you get into a sticky situation but that's another issue.

[Vern]

The tyre wear is negligible. Heck I run different diff ratios front and back, has not been an issue at all. (3.5 & 3.54)

[Charles]

Thanks guys - I think I will take the no worry option and add 2 new tyres to make a full set.
Cheers and thanks for input.
Charles

[donh54]

The rolling diameter of a tyre varies very little with tread wear. It's the length of the steel belts under the tread that determines the revs/km. Differences in tyre condition may affect your handling if you get into a sticky situation but that's another issue.

On the T650 I used to get 103Kph on the speed limiter with worn drive tyres, 107 for the first month or so on new ones! Had to be a bit careful for the first couple of months [biggrin]

[trout1105]

I have done the put new tyres on the front and put the old tyres that were on the front on the rear many times But these were only on cars that were town run abouts and never had any dramas.
However I did this once on my old Toyota Forerunner in the NT and went on a trip and blew both of the older tyres, I have Never done that again.
When I get new tyres I keep the old ones as they can still be used in the paddock and I also save heaps of $'s on the disposal fees as well, This way they aren't wasted and I get peace of mind on a trip knowing for certain that my tyres on the Disco are 100% Good to Go [thumbsupbig][bigrolf]