15 x 195 Fronts and 15 x 225 Rears?

[powerbookguy]

Originally Posted by rfernatt

fortow and I are running identical setups (unless he changed recently): 15x6 Rial wheels and Yokohama AVID T4 all-season tires in 195/50 all the way around. I've been running this setup since last January for almost 20,000 miles. The car has not been lowered and is stock in all other aspects.

No rubbing and no oversteer issues that I've been able to detect even in 'sporty' driving that has activated the ESP a couple times. I had it on the Dragon run recently and even pushing it in the wet, there were no issues. IMHO, it handles better, rides better, looks better, and you can rotate. I've rotated this setup three times now. YMMV, but I can recommend this configuration without hesitation based on my driving.

thanks a lot that is very helpful!

[BARNEY O]

I'm currently running 195x50x15 Toyo's up front on 6.5" wide DeCorsa rims
215x45x15 Toyo's on 7.5" wide DeCorsa rims. Could have gone up to 225x45 easily.But there is a catch, most of current aftermarket wheel suppliers offset is not quite right. That is, spacers may be needed or wheel might be hanging outside of fender. I custom widened out the DeCorsa"s to specifically fit under the car and allow proper clearance. Obviously this is not possible for the backyard warrior. Shop your wheel selection carefully.
unfortunatly there are not too many choices on 15x7 or 15x7.5 direct mount Smart car rims available.

Barney O. Home of the wedgie

[riversidesmart]

I'm planning on installing Rial 15X6 alloys front and rear. Yes, there are some great choices in tires in the popular 195/50 size, but one of my favorite summer performance tires is available (at least in the states) in nothing smaller than 195/55R15. The difference in overall diameter would be about 0.7" (based on data from Tire Rack). Any experience out there with 195/55's? All-weather tires (unless especially capable in the wet) are kind of pointless in my area.

Gil

[GHammerly]

Originally Posted by powerbookguy

has anyone tried turning off stability control by pulling a fuse (assuming there is one)?

I pulled it and drove it aggressively to see what it would do. On stock tires and wheels the front wheels locked up way too early so without ABS the brake balance is unsafe, if you expect short stops forget it. Also I tried a couple of hard trail braking maneuvers on sticky concrete highway off-ramp and it felt really unstable, like it was close to swapping ends. A bit of counter steer and straightening the line and reducing brake force got it gathered back together but it felt like it was close to the edge. (I autocross regularly so I know what that feels like)
I had felt the Stability Control working on that same off-ramp before and the car squirms a little bit as the sensors detect yaw and act on the brakes to straighten the line, much safer with the fuse in.

[daleharrison]

I am wondering if anyone can help with this?? I would like to use my stock Passion wheels with tires of one size that I can rotate front to back. Can this be done without sacrificing safety and if yes what size tire will I need to be sure about not oversteering and clearance in the wheel well. I am really leaning toward Michelins--any ideas or comments??

[fortow]

Originally Posted by daleharrison

I would like to use my stock Passion wheels with tires of one size that I can rotate front to back. Can this be done without sacrificing safety and if yes what size tire will I need to be sure about not oversteering and clearance in the wheel well.

Although people have used the OEM front wheels with wider tires, that is not advisable, not even for the 175 sized OEM rear tires. The front and rear OEM wheels are actually different widths because the tires are different widths. The wheel and tire widths have been optimized. Unless wheel width and tire width are matched there will be a deformation of the tread leading to wear and traction problems. There is a range of acceptability however.

In this reference you can find a number of calculators - there is "An ideal rim-width calculator" about 1/3 of the way down - Car Bibles : The Wheel and Tire Bible Page 2 of 2

After-market wheels do not have to be costly. Also, if you use aftermarket wheels you will then have the originals for spares - or you can use them for winter tires.

You can use up to a tire width of 195 without any problems whatsoever, slightly wider may work as well but, as has been mentioned, a 195/50-15 tire will give you almost the identical diameter as the OEM tires.
"Oversteering" is not an issue since the car has devices to prevent that from happening. Understeering is more of an issue with the original narrow fronts.

[RussBarnes]

Originally Posted by daleharrison

I am wondering if anyone can help with this?? I would like to use my stock Passion wheels with tires of one size that I can rotate front to back. Can this be done without sacrificing safety and if yes what size tire will I need to be sure about not oversteering and clearance in the wheel well. I am really leaning toward Michelins--any ideas or comments??

I have four equal Michelin 185/60-15's on four rear rims that I installed in about Feb or March of 08. I wasn't the first to do this, but pretty close. Not that I have a lot of miles on them (about 6,000 since then). I can say they ride great, are quieter than stock, show no wear, can be rotated and have one very small wear area (less than 1/16") on both my front fender edges that 99% of people can't see. Once I had the stablizer go off and slow down my very rapid speed in a tight 90 degree turn and once on a gravel lot when I was doing a tight turn with a lot of gas pedal. I run 36 psi rear and 28 front. Is it safe - I'm not a MB engineer with a test track to say that and stand behind it, but I can say that I feel safer than when it wandered all over the road and when the skinny front tires slid out from under me on wet pavement because I pushed it beyond the normal city use. If I really was picky I'd be playing with whatever adjustments I could on the front end because being a former race car fabricator, race car tire store I think I could get it to drive hands off in the wind (albeit with a lot of tire wear), but it's OK now for what it is.

[Ferrina_cdi]

There are lots of alternatives in the UK.

[MNMadMan]

Originally Posted by fortow

You can use up to a tire width of 195 without any problems whatsoever, slightly wider may work as well but, as has been mentioned, a 195/50-15 tire will give you almost the identical diameter as the OEM tires.
"Oversteering" is not an issue since the car has devices to prevent that from happening. Understeering is more of an issue with the original narrow fronts.

I bought 2 back steel wheels and did just this. Mounted 195-50-15s all the way around. They work great with no rubbing. Just as fortow has said.

Fortow, what are you running for air pressure in this setup? The tire place I bought these from said to run 32 PSI all the way around. So im curious to know what others have found that works best

[fortow]

Originally Posted by MNMadMan

...Fortow, what are you running for air pressure in this setup? The tire place I bought these from said to run 32 PSI all the way around. So im curious to know what others have found that works best

I hope you paid no attention to them. Invariably people in tire shops know very little about the intricacies of tires, or the proper mounting and balancing of them, or what air pressure to use and why, - they just sell them and pretend they they know what they're doing.

I run about the same as the factory recommendations, maybe a little less.
The front tires must have less pressure in them since the weight they support is considerably less than the rears.

Your tire place just told you to use the same pressure they put in every other car they service. They were wrong for both front and rear pressures.