Tyre Size Qn

[borgy Member Find all posts View Profile Close borgy]

Hi all

I am after any input / comments on the following. Have a prado with D694 265/65R17 (tyre 1) and we recently got a trailer that has 265/70R16 (tyre 2).

Is it good engough in a flat tyre situation to use the Prado spare on the trailer and visa versa??

Here was some info on the differences between the 2 sizes - seems very little -
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Results for your selected Wheel/Tyre 1
Rolling Radius 388.15mm
Circumference 2438.82mm
Diameter 776.3mm
Wheel Cover Size Size 007

Results for your selected Wheel/Tyre 2
Rolling Radius 388.7mm
Circumference 2442.27mm
Diameter 777.4mm
Wheel Cover Size Size 007

Differences between Wheel/Tyre 1 & 2
Rolling Radius 0.55mm
Circumference 3.45mm
Diameter 1.1mm

When your speedo reads 100km/hr you're actually at 100.14 km/hr
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I am no tyre expert so looking for help!

TIA

Cheers
Borgy

[Guest Close Guest]

1.1 mm wouldnt be an issue, Though I would suggest measuring them yourself as they may vary up to 20mm or more with wear.

Putting a different diameter on one side would possibly cause some wind up in the driveline.

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

Borgy, i also beleive that the 16 inch wheel will only go on the back axle of the car without mods to the brake calipers on the front.

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

Borgy,
I would be more concerned about wheel offset & clearance with the wheel against brake calipers etc on the Prado.
There may have been earlier articles on this situation before :?: :?:

Cheers,
Fazza

Hutch you beat me by two minutes :wink:

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

Recently due to an insurance loop hole I had the opportunity to get a slightly damaged rim repaired and keep it for the camper. Anyway, huge offset difference. The wheel actually went in and hit the chassis of the trailer so I gave up. Just check it out before you assume it will fit.

Matt

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

Your measurements wont affect your rolling diameter equation, so no driveline issues
But I would be confident it would affect the "driveability" of the car

I would reserve the equation for Prado wheel on trailer only, or trailer wheel to car in unavoidable emergencies only, and only ever on the back (1) because it wont fit on front and 2) because it wold have least effect on steering
Next problem is offset, the Prado wheel is (off memeory) positive 30 (?) and therefore a little unusual
Different offsets, whilst they may fit without rubbibg then could change your track and that would not be a good vehicle to drive, at a guess if you had an accident with the 16 on the car insurance co. would wave bye bye, even if it was only an emergency fitment

Here is a good site for doing comparisons on all things wheel and tyre

http://www.rims-n-tires.com/rt_specs.jsp

I'd be looking for another plan Borgy ops:

[borgy Member Find all posts View Profile Close borgy]

Hi all

And thanks to all your replies and info provided

I pretty much thought that about moving the 16's from the camper to the Prado - (that visa-versa was a last minute add to my original post)

My thinking / question really was mainly directed at taking the spare Prado tyre and putting it on the camper incase of a flat! [yes don't have a spare on the custom camper [as yet ops: ])!

Thanks again

Cheers
Borgy