different sized tyres

[vn5sp]

hi

just brought some 17's for my vn and 1 had a puncture so got a new tyre but it is 5mm smaller than the other 1. can this do any harm to my drive line, or any thing else.

and how much psi should i put in them.

thanks vn5sp

[DavoVP]

By 5 mm smaller you mean you had say 245/45 17's and the replacement is 235/45 17 ?? Short answer if yes is no, its 5 mm narrower if the front 2 number's are different.

But say it was a 235/45 and a 235/40 then yes, If you go around droping fat skids i have been told it may hurt your diff. I was advised not to run one 15 with one 17 on the rear of my dunnydore for to long becaue of it. Ok to get ya out of trouble.

But you should be ok.

On the front it wont hurt, as in damage wise, mayb in brakeing and cornering, But 5mm is **** all at the end of the day, you can get 5mm difference with an open center diff doing a big fat smokey kicken a single peger down the road on new tyres. So i wouldnt wory.

[mischa]

Only bad for your diff if you got a LSD because its constantly trying to keep the smaller diameter tyre up to speed.

I would just run the tyre on the front if you got a LSD otherwise it dosent matter.

[thewheeldeal com au]

Running on the front is probably worse because it introduces brake bias issues which will cause one wheel to lock up before the other.

What size are your tyres and what size it the replacement?

[vn5sp]

hi thanks for the quick replys, its got 225/45 on the front and 1 225/55 and 1 225/50 on the back, the 50 was the replacement, it has an open diff.

thanks

[thewheeldeal com au]

hi thanks for the quick replys, its got 225/45 on the front and 1 225/55 and 1 225/50 on the back, the 50 was the replacement, it has an open diff.

thanks

It's not 5mm different then.

225/45R17 = ~634mm outer diameter
225/55R17 = ~679mm outer diameter
225/50R17 = ~657mm outer diameter

Man what a mess...

You should really be running 235/45R17 all round.

It's not going to stuff your diff but it is unsafe from a brake bias perspective and running different sized tyres on the the same axle plane is illegal. Different fronts and rears is OK.