Staggered wheel sizes on MPS6

[MadAussie]

The term "differential, was originally employed in reference to the need to "differentiate" between the varying rates of rotation

I was banging my head against the table reading this thread, I'm so glad you posted that. Ridiculous argument was ridiculous.

Short answer, never run different sizes on an all wheel drive, you're just asking for trouble.

[shakespeare]

Hi guys, do you know if it is OK to use different brand tyres on the front of a 6MPS than the back although the same size?

As long as the size is the same you won't have issues with the AWD system, different brands may give you handling/grip issues though, unless they're very similar tread/compound.

[Doug_MPS6]

I would avoid it if at all possible, as the critical aspect is rolling diameter, and one never really knows how two different tyres of apparently the same quoted rolling diameters actually vary in practical use, i.e. when in contact with the road.

Secondly front and rear weight loadings differ and also vary from time to time as loads are added and subtracted from the passenger and boor space.

Thirdly, two different makes of tyres almost certainly wear at different rates, as well as wearing differently according to whether or not they are used on the steer or not. This is one reason why we rotate tyres from front to rear, to even out the wear. Two different tyres might start out with the same rolling practical diameters but this will almost certainly change over time, somewhere between the 20 - 50,000km you might be expecting from the tyres.

In my view there are too many variables to make a well-informed call on the reliability of such a move. It is easier and cheaper to replace tyres than it is to pull apart and repair clutches and differentials that wore out due to having to constantly accommodate differential rotation from two different sets of tyres.

[projectrracing]

I'd hate to know what the centre diff costs with all it's electrics and clutch plates to replace or service. Ouch!!!

[MadAussie]

[Axspeed6]

if your vip go to the vip section and download the mps 6 workshop manual supplement in it is cross-sectional view of the gbox and transfer case with a power flow indication,
i wouldn't stagger the wheels on a 6 a must admit it would look good but the simple fact of that the rear tyre's frictional coefficient isnt the same as the front is enough to stuff your transfer case it might last for a month or a year but eventually it will cause massive problems

---------- Post added at 01:22 PM ---------- Previous post was at 01:19 PM ----------

I'd hate to know what the centre diff costs with all it's electrics and clutch plates to replace or service. Ouch!!!

i could get a price for everyone my mate works for spare parts at werribee mazda i'd expect around the $5000 - $7500 brand new

[projectrracing]

if you google 'mazda 6 mps drivetrain', those pics are online.

[Axspeed6]

As long as the size is the same you won't have issues with the AWD system, different brands may give you handling/grip issues though, unless they're very similar tread/compound.

There is guys on msf that say dont even run different tyres as different compound's have friction rates and different way's of dealing with load and this stresses out the transfer case

[Coop]

Hi guys.

Apologies for the thread resurrection and this being my first post but I have been searching for information on this subject and while the middle section of this thread went a tad off topic, I still found I useful.

However!

I am looking to run 8j front 9j rear staggered wheels with 225/40 and 255/35 tyres respectively. This gives a 1.5mm diameter difference and a 4mm circumference difference. I appreciate the recommendations saying that you should not stagger and should always use the same brand tyres but if the riffs were so sensitive then surely many would have been busted a long time ago?

My point is, not everyone replaces all 4 corners at the same time. I have been running Khumo on the front and Bridgestone on the rear for 5000miles or so. Shouldnt this have caused an issue?

Also, a lot of the information out there is for AWD cars. The 6MPS is not AWD. It is electronically controlled 4WD which is 2WD most I the time unless you floor it or the ECU detects slip due to conditions or driving style.

Is this not correct?

So because our rear wheels are not always driven, when the diff or coupler disengages the rear wheels while cruising or driving about town, does any wind up of the diff get released or are the rear wheels always engaged, just with no torque being sent to the rear?

Any further information welcome!!

[99GTT]

Hi guys.

Apologies for the thread resurrection and this being my first post but I have been searching for information on this subject and while the middle section of this thread went a tad off topic, I still found I useful.

However!

I am looking to run 8j front 9j rear staggered wheels with 225/40 and 255/35 tyres respectively. This gives a 1.5mm diameter difference and a 4mm circumference difference. I appreciate the recommendations saying that you should not stagger and should always use the same brand tyres but if the riffs were so sensitive then surely many would have been busted a long time ago?

My point is, not everyone replaces all 4 corners at the same time. I have been running Khumo on the front and Bridgestone on the rear for 5000miles or so. Shouldnt this have caused an issue?

Also, a lot of the information out there is for AWD cars. The 6MPS is not AWD. It is electronically controlled 4WD which is 2WD most I the time unless you floor it or the ECU detects slip due to conditions or driving style.

Is this not correct?

So because our rear wheels are not always driven, when the diff or coupler disengages the rear wheels while cruising or driving about town, does any wind up of the diff get released or are the rear wheels always engaged, just with no torque being sent to the rear?

Any further information welcome!!

Oh oh... Can of worms officially opened with them words ...


Sent from my iPhone

[SarcasticOne]

feel free to ignore all the warning/advice against running staggered wheels...
we'll show you 0 sympathy when you have issues

[bd581]

I believe it was the lovely Rachel Hunter (back in her prime) that said it the best.

It won't happen over night, but it will happen

[kmh001]

Also, a lot of the information out there is for AWD cars. The 6MPS is not AWD. It is electronically controlled 4WD which is 2WD most I the time unless you floor it or the ECU detects slip due to conditions or driving style.

Is this not correct?

No, it's not correct. 6MPS is in fact AWD. Even when coasting down hill with the throttle closed the rear wheels are engaged. There is plenty of info about it here if you search for it. You can also search for my video which shows diff coupling control voltage in a range of different operating situations. Nothing like objective evidence to show what's really going on.

[Coop]

Thanks for the replies guys. Except for the sarcasm you've replied with something constructive and clarified my mistake.

Thats why I came here to OZ MPS instead of the US guys at MSF. That would have gone down in ( bigger ) flames.

[TWENTY B]

STAGGERED FITMENT REFERS TO RIM WIDTH...
if rolling diameter of the tyres is the same, than staggered fitment should have no effect on the driveline...

[Doug_MPS6]

It might be OK if you research the rolling diameters and ensure a high level of equivalence. I tend to avoid using different tyres front and rear.

BTW, I certainly see little sense in using a fatter set at the back, as was the original rationale for this thread. It might make sense if it were a RWD car but while it is an AWD car, as explained thoroughly in the preceding posts, one might say that the dominant effort in the average drive is directed to the front. Hence one might ask "why would you apparently attempt to ensure greater traction on the rear"? However, traction isn't everything and I guess if one was attempting to modify or rectify a handling issue, such as increase or decrease oversteer, then such a move MIGHT have some merit.

You might find different brands front and rear might affect such issues too, due to varying grip and wall flexibility. If you are not sure what the outcomes are likely to be, especially if you punt your car along pretty hard, then maybe it is best to either not do it at all or if you do, then at least to take it easy at the outset until you discover any handling quirks.

[RedDjinn]

feel free to ignore all the warning/advice against running staggered wheels...
we'll show you 0 sympathy when you have issues

What Sam means.... if you proceed with different wheel size after info provided from long time knowledgable 6 owners, your gana get yourself into trouble down the track.

They offered there advice to save you problems, now its up to you what you do with it.