Please ignore my ignorance but .....

[chris g]

If RR exactly same then go ahead...

But if not exact I would get new tyres

Being 'close', whatever Brad says, would not be ok with me...

[stuey]

I can't imagine 255's fitting easily on the rear of a VR4 without rubbing like crazy.. (unless you've got adjustable coilovers jacked right up)

[CANDEE]

I was running different sized tires on my old leggie with no issues, was running 205/55/16 on the front and 215/55/16 on the back.

Thats even with launches on the 1/4 mile.

J

[Pablo]

thanks for the input guys its nice to know this group is a community! official stats are
rear 255/55/16 front 205/50/16

My only issue at this stage is during and after the day at pod my gearbox seems to be drinking a lot of ATF which tells me the gearbox is either leaking or straining so i'll be changing rubber first thing monday! my only real question at this time is what would the optimum tyre be for a auto with Ayc???

[Pablo]

If RR exactly same then go ahead...

But if not exact I would get new tyres

Being 'close', whatever Brad says, would not be ok with me...

they are 255/55/16 an no there is no rub or signs of and susp is standard

[Pablo]

Are you sure they are 255's? That is really really wide!

As long as the sizes are close you will be fine. For example 205/55/16 and 225/50/16 are the two stock sizes and work fine together. 225/45/17 and 255/40/17 is another good option.

Sorry misquoted lol yes brad im running 255/55/16 at the rear but no rub an still stock suspension maybe its not rubbing due to front being 205/50/16? either way the only thing i see suffering is my gearbox as it likes its atf an whines when it gets low which seems to be a lot recently?

[bradc]

Pics?

That is a massive difference in rolling radius and I wouldn't drive on them like that! Are the wheels the same all round or wider at the rear.

[chris g]

When I use the word close I do not mean rubbing or touching susp or bodywork...

And if odd sized tyres are used and apparently no probs does not really mean ok

It may be some time before it goes bang, or then again it may last forever or until after you sell the car...

I would not put odd sized tyres on my VR-4 and take the risk

There are 'official stats' - Mitsubishi put same wheels tyres front and rear

Best advice - change all four wheels/tyres at same time to bigger/smaller

Advising differently is foolhardy at the least..

If you want to put different sized tyres on front compared to rear - your choice and risk

[gareth001]

On stock rims, the tyres should be 205/55/16s

Tyre choice is a lot down to personal preferance, but have a look at this thread:

http://www.clubvr4.com/forum/showthr...ight=tyre+size

Falkin 452 or 912 seem to be a good choice currently.

[bradc]

Mitsi from factory shipped the EVO 5 through 9 with a different ratio gear in the transfer case compared to the rear diff. This difference is small, but even then the difference is greater than running either the 205/55/16 + 225/50/16 combo or the 225/45/17 + 255/40/17 combo. It really isn't a requirement to run the same size all around.

[chris g]

Sounds ok for evos then...

But we have a vr-4...

But even if same applies to vr-4 I would not fit different size tyres...

Might be revealing to have a poll, ask who would do so...

[Pablo]

ok slightly confused now?

My understanding is current tyre combo is bad, understood!

AYC enabled cars should be running 225s? but can also run combos like 225+215? but 205s are also good? So basically there is half a dozen views on whats right? .................................... I think i need a beer lol .....

[chris g]

No!

IMO - have 4 wheels and tyres same size - change to different size of tyres/wheels as you choose but same on all four corners

[Beastlee]

Most 4x4s will recommend same tyres at the same size all round. And As mentioned all 4 must be changed together.
I'm miffed as the inner edge of my front right is badly worn but the two rears are perfect, still going to cost me £300+ for one tyre!

[Turbo_Steve]

I'm with brad here: It's not quite such a big deal as you guys are making out!

It WILL prematurely wear drivetrain components, but we're talking halving the lifespan of bits designed to do 500,000miles.

The differences being discussed are no more than typical tyre wear can achieve. 4WD isn't THAT fragile on these cars.

[Pablo]

I totally agree guys it was never an issue about changing the tryes once i realised what the last owner had done, now i know the current are wrong i was after advise as to what dimensions worked best in general as there still seems to be a debate on sizes between ppl here an if having AYC contributes to decision on whats optimal?

[bradc]

Chris, my point being that we have the same transfer case (same part number in fact) as EVO 5 and 6's and the 7-9's are virtually the same design for the gearing, just that they have the clutch packs for the ACD which is irrelevant to what we are talking about.

Basically if it is fine for an EVO 5-9 to have a wheel speed difference front and rear of 0.15%, then it will be ok on our cars to have a small difference, for example:

205/55/16 and 225/50/16 is 0.08% (roughly half of the difference)
225/45/17 and 255/40/17 is 0.23% (ok, a little bit more than the evo difference!)

How many people here run tyres with more than a few mm of tread difference though? For example, you have brand new 225/50/16 at one end and 225/50/16 at the other end as well, but one set has only 5mm tread, the other has 8mm of tread.
This gives you 0.96% difference, much more than what we are talking about above!
2mm is 0.64% and 1mm difference is 0.31%




Pablo, we aren't having a debate, I'm right

First of all what size are your wheels, we need to know that in order to pick a size that suits your wheels.

[chris g]

Tha's right Pablo, Brad is always right on things technical..

If HE states it then it must be so...

Factual % are one thing but opinion is another

So when running a VR-4 and particularly my VR-4 I would NEVER put different sized tyres on it...

Tyre treads and gearing ratios can be calculated to support a view but does not change my view nor THe position of virtually everyone on this Forum

They have the same sized tyres on their VR-4

And that can be seen as a consensus about what tyres to have on a VR-4

[Turbo_Steve]

Chris, that's a dreadful response:

Brad is OFTEN wrong about things...especially where it pertains to engines

However, we've been through this drivetrain discussion a few times, and he really does have a valid point on this one.


Look at it this way, Mitsubishi say you should have the same sized wheels and tyres front and rear.

They also say the car shouldn't be running more than 260bhp.
The ECU cuts at less than 1Bar if boost pressure.

And yet many of the forum members defeat these limits for our own ends.

It's one of those things: the bigger the difference from standard, the more likely you are to encounter failure / the quicker it all wears.

[chris g]

Not certain how it is dreadful but thats what you get from a non-technical owner..

But I am not certain that we have 'been through this drivetrain discussion' in that it supports the use of different sized tyres on front to rear..

I should forget the use of Mitsubishi as guide to car spec/performance and just stick with MY view that I am happier with the same size tyres on all four wheels

And I guess there are more VR4 owners doing the same rather than odd sizes..

Thats my dreadful view...