Changing tire sizes?

[Laconian]

My husband will only buy Michelin (yes I know) so I'm thinking the Defender M/S look great. But our Outback uses 225-60R18 tires, which is a size which has many passenger car options but few M/S SUV/truck options. What are the considerations or tradeoffs when picking a tire that isn't OEM sized? We'd probably have to recalibrate the speedo to reflect the new circumference, but what else do I need to keep in mind?

[Laconian]

Also, is there any margin of adjustment of tire width on a given wheel? Or am I absolutely stuck with 225?

https://www.michelinman.com/tire/michelin/defender-ltx-m-s

[Soup DeVille]

Different tires do have slightly different dimensions in the same sizes.

I very rarely put the same size tires back on. Often the speedometer runs a bit off, but never so much it concerns me.

The station wagon wears the police spec size, which was a couple sizes up, and the Land Cruiser wears the biggest Nittos I could stuff under it without lifting. I think I went 20 mm plus on the Civic.

What I would do is hit up the Subie forums and find what others with your car have run.

[Soup DeVille]

What exact model Outback is this?

[BimmerM3]

The biggest concern is that the bigger tires will rub against something, especially when turning. But most cars have enough room for some extra rubber. IMO, your best bet is probably to find a Subaru forum and see what other people have done.

It could also affect gas mileage and acceleration to some extent.

Would you consider getting new wheels? It's possible that you may find more options in a similarly sized tire, but different rim size. My Explorer either came with 17s or 18s. The 18s have very few A/T tires in its stock size, but there are tons of options in the stock 17 size.

[Eye of the Tiger]

I like tires.
You could go with a 255/55-18 and have negligible speedometer error.

[MX793]

Tires have maximum and minimum recommended rim widths.  You'll need to consult the tire manufacturer (Tire Rack also publishes this, as do other major retailers).  It's rare for a manufacturer to fit the widest possible tire for the rim as OEM.  They usually run a size or two narrower.  My Mustang came with 255s on 9 inch front rims, but I run 265s on my race wheels.  I ran 255 tires on 8 inch wheels on my last Mustang.  I'd run wider tires on my current car, but there isn't much space between the tire and the strut.  I'd need to change the offset with spacers or different rims.  On my last one, the front tires would rub the fender liners at full steering lock.  The OE tire size for the wheels I had was 235.  So that's something else to watch out for if you want to fit wider tires on stock rims.

I upsized from 205 to 215 on my Mazda.  205 was kind of an odd ball size at the time and a lot more expensive than 215, which had more options.

[BimmerM3]

Also, are you more concerned with the M or the S part of M/S? If it's just the S, they sell some all-seasons with the 3 peak mountain snowflake designation, which is more meaningful than M/S anyway.

https://www.tirerack.com/tires/tires.jsp?tireMake=Michelin&tireModel=CrossClimate+SUV&partnum=26WR8CCPSUVXL&vehicleSearch=false&fromCompare1=yes

These are both also listed as all-seasons, but still have the M/S label.

https://www.tirerack.com/tires/tires.jsp?tireMake=Michelin&tireModel=Primacy+MXM4+ZP&partnum=26HR8MXM4PXLZP&vehicleSearch=false&fromCompare1=yes
https://www.tirerack.com/tires/tires.jsp?tireMake=Michelin&tireModel=Primacy+A%2FS&partnum=26HR8PAS&vehicleSearch=false&fromCompare1=yes

[r0tor]

Crossclimate tires come in the original size and appear to get great reviews

[2o6]

I don't think you can actually calibrate speedometers for most modern cars


Just keep in mind that tire circumference is also part of gearing. A change in width wouldn't have as much of an impact as a change in sidewall.


I don't think it would be worth it to go more than say 10mm + width on a passenger car.

[12,000 RPM]

As long as the circumference is closer it's all good. I think ties lose half an inch of circumference as they wear anyway

[MrH]

https://www.wheel-size.com/calc/

[giant_mtb]

As long as the circumference is closer it's all good. I think ties lose half an inch of circumference as they wear anyway

Well. No. They lose circumference over time as the tire wears down. Not many passenger car sized tires are rockin' 1/2" tread to begin with...they'd be bald as shit. 

[CaminoRacer]

Well. No. They lose circumference over time as the tire wears down. Not many passenger car sized tires are rockin' 1/2" tread to begin with...they'd be bald as shit. 

Well it would be 1/4" tread on each side.

[Eye of the Tiger]

Well it would be 1/4" tread on each side.

Tires are round, and therefore do not have sides.

[CaminoRacer]

Tires are round, and therefore do not have sides.

U got me

[Laconian]

https://www.wheel-size.com/calc/

How the hell do I know what my rim size and offset are?

[Laconian]

Crossclimate tires come in the original size and appear to get great reviews

I'm under the impression that those tires are for performance SUV folks who normally drive summer tires and tend to fly into ditches when a quarter inch of snow hits the ground.

[Laconian]

What exact model Outback is this?

Limited 2.5i

[Laconian]

I don't think you can actually calibrate speedometers for most modern cars


Just keep in mind that tire circumference is also part of gearing. A change in width wouldn't have as much of an impact as a change in sidewall.


I don't think it would be worth it to go more than say 10mm + width on a passenger car.

235/60R18 sound gud to you? That's +10 over 225.

[Galaxy]

What does BFGoodrich offer? They are part of Michelin.

[Laconian]

What does BFGoodrich offer? They are part of Michelin.

Oh vraiment...

[Laconian]

Nope, gotta be Michelin.

[MX793]

235/60R18 sound gud to you? That's +10 over 225.

You'll be 1.6% larger, which is minimal.  That's like 1 mph at 60.

[r0tor]

I'm under the impression that those tires are for performance SUV folks who normally drive summer tires and tend to fly into ditches when a quarter inch of snow hits the ground.

crossclimate tires are in a new "all weather" class of tires... They are like all seasons but perform much closer to dedicated winter tires in the snow/ice

[SJ_GTI]

235/60R18 sound gud to you? That's +10 over 225.

IMHO, without know all the specifics of your car/wheels, this is the simplest, best solution. It is EXTREMELY unlikely (like, less than 0.00001%) that 235/60R18 wouldn't fit a wheel that used 225/60R18 from the factory. MX793 already explained in detail so I won't go in to the whys and hows again.

[MX793]

Struggling to wrap my head around why you would want to put truck tires with a highway tread on an Outback.  In terms of grip, a highway tread M+S truck tire won't really perform any better than an M+S all-season passenger tire.  They use similar tread patterns, so it's not like you get a more open, grabbier tread pattern.  What the truck tire gets you is a more heavily reinforced casing with extra radial belts designed to deal with heavier loads that a truck or cargo van may carry.  This also typically results in a stiffer tire that will compromise ride quality on a passenger vehicle.  You also tend to pay more for the higher load rated construction.  Unless you are hauling/towing, I'd stick with a passenger tire.

[veeman]

Your husband is from France if I remember correctly.  Now I understand the insistence on Michelin.  Vive la France!

[BimmerM3]

I'm under the impression that those tires are for performance SUV folks who normally drive summer tires and tend to fly into ditches when a quarter inch of snow hits the ground.

They have the "3 peak mountain snowflake" certification, which is more meaningful than "M/S". "M/S" is basically just based on tread design. The mountain snowflake symbol requires actual testing.

[r0tor]

Yes, crossclimate are the tires you want