what was I thinking..??

Hi there silly, one big problem that stands out is that your speedo will be well out of wack. Some where on this site is a tyre diameter to speed conversion of one size to the other. As for placing two odd size diameters on the vechile is one will rotate faster than the other and I would expect some very angry spider gears in the diff yelling to you. Good luck. I replaced all my tyres including the spare when I go away, and swap the normal road tyres back on again to save wearing out my good ones for off-road. When needs be, I shall change half used off road tyres onto my alloys, to put new ones onto the steel rims, then it won't matter if I need to use and odd steel or alloy.

Hi,

Suggest Google tyre markings to find an explanation of just what all those numbers mean. There's a lot of information there if you know how to decode it!

265/75/16 means it fits a 16" rim, and the height of the cross section "balloon" is 265mm which is 75% of its width.

215/70/16 also fits a 16" rim the height though is only 215mm from the rim, and that is 70% of the width of the "balloon".

That 50mm difference makes a change of about 13% to tyre diameter, so the speedo will read 13% high and of course you'll need 13% more RPM to achieve the same road speed with the smaller tyres. You will not be able to mix sizes without damaging your diff, so you'll need the right sized spares too!

Sorry....... think I'd try to sell them and start again.

Cheers

John

It will work ok, but





reserve my 265/75/16 MT tires.

I just realised that by 215/70/16, the 70 stands for the % of the tread with

PradoMad
Well, you do have a problem.
The bigger tyres can't be used with the smaller ones, sorry, or even fitted to and used on the vehicle.

The front or rear diff will not like the constant difference in rotational speed.You have gone to 97mm smaller dia and that is around 12+% smaller.
The smaller wheel is 305mm less circumference than the bigger wheel.
The rotational speed may be enough to trigger traction control if fitted.
Definitely the ABS will not know what to do and it would appear to be very dangerous to me.
If used on one wheel or even two wheels on the same axle then the centre differential will also be running it's spider/differential gears to try and make up for the difference in drive rates being supplied to the front and rear axles.
It will be working overtime, as it is designed to only cater for slight differences of rotational drive speeds when cornering, never constantly being in that situation.

If you have DSC or TC, Directional Stability Control or Traction Control or both, it/they too will be unable to allow for the difference and strange things will happen if and when those systems are activated by the electronics. Probably not good things.

Did you buy those additional rims or did a tyre fitter fit them to those rims? if a tyre fitter did, they would be held responsible for the ensuing accident.

Despite the obvious instability and sudden additional wear rates which will be happening the vehicle will be dangerous and it will sit down on that end or side wherever one of those wheels is placed.

There will be a myriad of other reasons in addition to what I have mentioned to convince you to sell them and NOT to use them at all.

Normal recommended tyre difference when changing from one set to another size is 2.5% You are nearly 13%.
The jury will decide. I have.

Ross M

I bet the Prado accelerates really well now! Might have a much lower top speed, but your gearing will make for quick take off, burnouts maybe? Whoo hoo.

And I'd think it looks pretty silly with those tiny wheels inside the arches.

I can't believe a tyre place fitted those tyres knowing they were going onto a Prado.

Sell them, quickly, to someone with a Commodore.

Tim

Thank you all.
I bought them with the rims. They came off a Prado.

I will put my MT muddies back on, sell those skinny ones and try to find a set of original wheels with road tires.
Just thought that I want to preserve those MT's as they are awesome in the high country.
...a well, lesson learned and money wasted; some..!
JS.

Hi there JS, they are off an RV prado which makes them only 6 inch wide rims and 16 in diameter (meant for 90 prado without flares). Your is obviously a GXL with steel wheels and a 90 series going by the picture. Yours would be 7 inch wide but you also went up a size from the original factory specs on the GXL when you have put the mickeys on, the original only been a 70 profile. Been a series 2 90 series you may or may not have traction control ?? (was optional) I would imagine it would certainly not feel to stable running those skinny wheels. You could run them if you really needed to, to get yourself out of trouble but you would need to run all 4 at the same time and you would not be able to run the mickeys even as a spare on one corner more so due to it been an AWD set up. As mentioned above Id get rid of them and buy another set. Problem is its hard to shift those 6 inch skinnys as everyone wants the 7 inch wide rims. You would certainly notice a big difference in power. I went up to a 75 on my grande V6 90 when I had it and I noticed the power loss and the fuel bill climb. I kept the 70 profile when I next got my 90 grande turbo diesel as to not lose the power.........I have 120 now V6 and am in the process of trying to find some muddies in a 65 series profile, BF'g in muddies only make a 70 for mine which are illegal. Im only allowed 15mm extra rolling diameter over standard, the BF's put me 28mm over...