265/70/17 with 265/65/17 spare

[masso Senior Member Find all posts View Profile Close masso]

I know its been covered before, but if i fit 265/70/17 Cooper ST's and keep the 265/65/17 GrandCrap spare.. and if i need to use the spare for short distances ,... enough to get to somewhere to fix the offending ST.. then whats the REAL story in relation to Diff damage/stress etc for having one tyre a smidgeon different to the other on the axle? My simplistic view is..i have a differential between the wheels, surely that will account for the different wheel sizes.. just as it does in a corner accounting for the lesser wheel turning of the inside wheel. So my simplistic view is... it should be fine for the short distance to the Cooper repair shop?
Anyone comment??

[speedcomm Senior Member Find all posts View Profile Close speedcomm]

I was also doing the same thing till I came accross a 275/65/17 at the right price ( nill) which is much closer to the 265/70/17. The drama I see is that you are in a full time 4wd vehicle which has an LSD in the rear so if 1 wheel is smaller in diamtere the LSD will be fighting all the time and would wear out pretty quick I would reakon, not sure about on the front but I would think it would then stress the centre diff. My spare is not the same but it is much closer, apparently according to my tyre joint " close enough " Touch wood no flat yet after 50 odd K.

[White Lightning Junior Member Find all posts View Profile Close White Lightning]

All the tyre gurus i spoke to said dont do it..also the hassle of having to find a tyre repair shop whilst on a trip to urgently fix a tyre would be a pain in the sphinc...what if it cant be repaired....what if the tyre shop doesnt sell 17" coopers. what if's are endless.

youve got an A grade fitout on you car , so might aswell go for the cooper st spare

On a side note, It almost ended in divorce when i sold the hard wheel cover cos it wouldnt fit over the bigger spare.
What is it with women and hard wheel covers??

[pradooman Lurker Find all posts View Profile Close pradooman]

Prado VX - Larger spare tyre - Modifications?

Interesting stuff. Do you have any idea whether a 285x70x17 can be mounted on the rear door stock mount and if not how the problem can be solved?

[Chippy Addicted PP Member Find all posts View Profile Close Chippy]

I imagine the 285's would rub .... the 265/70 17's do.

Have a look Here for some ideas for spacing the carrier out a bit further.

Cheers
Chippy

[pradooman Lurker Find all posts View Profile Close pradooman]

Spare Tyre Spacer

Hi Chippy....spot on! Many thanks

[StormyKnight Advanced Member Find all posts View Profile Close StormyKnight]

An interesting question....
I asked a similar question with the 90 series tyres going from 265/70R16s to 265/75R16s. What if my spare was still the smaller size?

It turns out the larger tyre has a larger mathematical* circumference by 3.4%.

* As it turns out not all tyres are the same size even if they are marked with the same dimensions - you can expect a variance especially when comparing ATs & MTs of the same stamped size.

If this tyre was fitted, instead of the larger tyre, the rear diff would be rotating at 3.4% more on that side than the other side. Also the centre diff will be rotating 1.7% more on the end of the car that the tyre is also fitted.

Now to get it into perspective, a 3.4% difference in rotation on a tyre is equivalent to constantly turning around a roundabout with a radius of 43.45m..........thats quite a large roundabout.

Yes I can provide the maths if required... :shock: :wink:

So whilst in an ideal situation, tyres of equivalent diameters would be ideal, using a smaller tyre will not do significant damage in the short term. Afterall what about all those european cars that now come with an undersized spare so that it will fit in the boot? ....And if you live in Canberra say...aren't you always turning left or right!

Cheers

[lofty Advanced Member Find all posts View Profile Close lofty]

Re: 265/70/17 with 265/65/17 spare

.. and if i need to use the spare for short distances ,... enough to get to somewhere to fix the offending ST..

Have any of you guys used the ARB or similar repair kits?

We bought one at a 4wd show a year ago, only used it once on the work van but the plug lasted a couple of months b4 the tyre started losing pressure.

As a temporary measure i think they are a brilliant kit to have in the back.

Any thoughts :?:

[StormyKnight Advanced Member Find all posts View Profile Close StormyKnight]

Re: 265/70/17 with 265/65/17 spare

As a temporary measure i think they are a brilliant kit to have in the back.

Any thoughts :?:

Yep use these guys as as a temporary measure only to get you back to civilization only. Then get the tyre professionally inpected to see if it safe to repair.

Touchwood...haven't needed mine yet!

[fergs Junior Member Find all posts View Profile Close fergs]

265/65/R17

Hi guys
First post for me , Was just wondering can u get 265/65/R17 in BFG AT's or do I need to run 265/70/R17 BFG AT's.

As i dont understand there web tyre guide very well. And u guys being in the know thought I would ask advice.

Cheers Nathan

[Hutch Addicted PP Member Find all posts View Profile Close Hutch]

I beleive 265/70/17 only as we would probably all be running them.

[waltec Senior Member Find all posts View Profile Close waltec]

At the Brissie 4x4 shop the BF Goodrich guy told me that they were about to bring a 265/65/17 AT to Australia soon, apparently its in production OS now.

Matt

[mjrandom Out of control poster! Find all posts View Profile Close mjrandom]

I have heard that before but I sincerely hope this time it is true...........