Winter Tire/Wheel Mystery

[Hugh]

I recently ordered a 2007 9-3 2.0T Sportcombi which is due to arrive in a few months which will be right in the middle of our snow season so I have been thinking about winter tires.

My current car has 16" OEM wheels but the winter tires are on 15" steel wheels ( I have always followed the experts advice to drop down one size and put on narrower winter tires). My dealer checked out the GM/Saab parts data base and confirmed that I could use these wheels on the Combi with no problem. Much to my surprise I saw that Tirerack website had a warning for the Combi,stating not to go below 16" for the winter steel wheel. Tirerack advised that normally,15" wheels would be OK,but since Saab had increased the size of the brake calipers in the 2.0T models,the 15' wheels will not fit.

My dealer just received a shipment of 15" steel wheels for the 2.0T Sedans and Combis from GM and tried one on a new Combi. Surprise,surprise.....they will not fit !!! The calipers prevent the wheel and hub faces from getting anywhere near one another.

The dealer has asked for an explanation as to why the data base appears to be in error and what they are supposed to do with a truckload of wheels that don't fit.

[pokeyjoe]

I'm afraid there isn't much of a mystery there.

[brunp]

That sounds like a Saab database problem, not yours. Most of us would have confirmed that 15" rims will not fit on any '05 or greater 9-3ss. The '04 still had a linear model line up with 15" rims, but only the linears of the '03 and '04 year would have been able to fit 15" rims.

However, most older Saabs will fit the 15" tire size, so I would not see it going to waste. Old 9-3's can take the 15" size, Saabscott's 9-5 are using the steel rims I had for my '04 9-3ss.

Paul

[Hugh]

Thanks for the info.....I had a feeling that was the story,despite the GM party line.

[thomjam]

I have always followed the experts advice to drop down one size and put on narrower winter tires

not sure I agree with part of this expert advice.

a narrower width tire will certainly help in snow as it will not float and get down to the hard packed snow or road depending on the depth/conditions/etc.

by dropping down one rim size you will get a larger sidewall to compensate, yet, how does this effect snow/ice performance?

tread pattern, rubber compound, studded or not really impacts how the tire performs in snow and ice.

with these criteria on a standard size rim, the tire will perform in the snow/ice conditions.

now buying another set of steel wheels to save the alloys, great idea.


Jaime

[SMHarman]

Our Winter wheel / tyres are the 2.0T alloys with a winter compound tyre on it. They fit.

[ElectricBlue]

yes, there are some rumours:

.. but, we just picked up our 9.3 1.9d Kombi MY 2007 today

and "15er BORBET CB70535 7Jx15H2 ET35 with 195/60R15 Winter Tire fits perfect.
(we drove them on a 9-5 MY03 2.2d recently)

[SMHarman]

Originally Posted by ElectricBlue

yes, there are some rumours:

.. but, we just picked up our 9.3 1.9d Kombi MY 2007 today

and "15er BORBET CB70535 7Jx15H2 ET35 with 195/60R15 Winter Tire fits perfect.
(we drove them on a 9-5 MY03 2.2d recently)

But the 1.9d does not have the supersize me brakes and calipers on it that the Aero does.

[ElectricBlue]

but the MY07 1.9d cab has bigger brakes, as a guy here reports today.

[SMHarman]

Originally Posted by ElectricBlue

but the MY07 1.9d cab has bigger brakes, as a guy here reports today.

There were 3 sizes of brakes at one point. So they may have got bigger, but are they the biggest?

[sbl]

Originally Posted by thomjam

a narrower width tire will certainly help in snow as it will not float and get down to the hard packed snow or road depending on the depth/conditions/etc.

by dropping down one rim size you will get a larger sidewall to compensate, yet, how does this effect snow/ice performance?

The narrowe tire puts more pressure on the contact patch and, in this case, helps by not plowing the snow under the tire. It is a general recommendation to use narrower tires for snow than for summer.

[thomjam]

The narrowe tire puts more pressure on the contact patch and, in this case, helps by not plowing the snow under the tire. It is a general recommendation to use narrower tires for snow than for summer.

yep, totally agree and said the same thing.

however, a narrow tire does not require a larger aspect ratio tire which is what you get going from a 16 inch rim to 15 inch rim.

the overal diameter is the same as the sidewall is larger.

my point is what difference does this make??

imho - none!!

stay with a 16 inch rim, mount a narrower tire with softer compound and a more agreesive tread pattern preferably siped!!


Jaime