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i just bought this car and tires are not the best so i checked discount tire, tire kingdom and tire rack then as i was walking by the front tires i noticed they were made by kuhmo all i could find were the contentials. hope that little bit of info helps.
 

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So far Continental and Kumhos are the only two companies that make the standard size tires to fit the stock rims. Originally the Continentals were all that was available. The Kumhos are a much better tire The front rims being only 4.5 inches wide are the difficult ones to find to match the rear 5.5 inch wide rims (both are 15 inch rims) Thus the common swap of putting the rear rims also on the front, You only have to replace 2 rims to make them match instead of replacing all 4. Once they are all 4 rims at 5.5 width, your options of tires is much greater, increased mileage ratings, tire overall size, etc. I changed to 180\60 quite awhile ago and the difference was truly amazing!

http://www.smartcarofamerica.com/forums/f409/kumho-tires-127922/
 

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So far Continental and Kumhos are the only two companies that make the standard size tires to fit the stock rims. Originally the Continentals were all that was available. The Kumhos are a much better tire The front rims being only 4.5 inches wide are the difficult ones to find to match the rear 5.5 inch wide rims (both are 15 inch rims) Thus the common swap of putting the rear rims also on the front, You only have to replace 2 rims to make them match instead of replacing all 4. Once they are all 4 rims at 5.5 width, your options of tires is much greater, increased mileage ratings, tire overall size, etc. I changed to 180\60 quite awhile ago and the difference was truly amazing!

http://www.smartcarofamerica.com/forums/f409/kumho-tires-127922/
I heard the speed is measured by the front wheels. Would changing them to a larger size mess with the Odometer?
Also I have NO power steering, it's fine when moving but parallel parking etc are a lot more challenging than any other car, how much more resistance would wider tires add?
 

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my 2008 and my 2009 both were pure's without power steering. I didn't notice much change with the tire change, and now that I have one with power steering, I still don't see much difference with ps or without.
 

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I heard the speed is measured by the front wheels. Would changing them to a larger size mess with the Odometer?
Also I have NO power steering, it's fine when moving but parallel parking etc are a lot more challenging than any other car, how much more resistance would wider tires add?
yes, the speed is measured/regulated from the front tires, if you go bigger, you'll gain a couple MPH in top speed, if you have the urge to go 90+MPH in a car with a 6 foot wheelbase and 1800 pound curb weight. 185/60-15's have me going 1 mph over indicated at 50MPH, stock tires are -2MPH, all from GPS data.

I just had open heart surgery 4 months ago, I have no problem with 195/50-15's or 185/60-15's, consider having your chest ripped open and stitched back together, and can't lift anything over 10 pounds for 3 months, i was driving my smart 4 days after (i'm bad, they say 4-6 weeks, LOL)
 

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So far Continental and Kumhos are the only two companies that make the standard size tires to fit the stock rims.
In additional to the Kumho Solus KH16 and Continental ProContact you can get Nankang AS-1 and Vredestein Quatrac 5 tires in the original OEM sizes for a non-Brabus Model 451. The OEM sizes I'm referring to are 155/60R15 (Front) and 175/55R15 (Rear). Several companies including Yokohama, Bridgestone and possibly Hankook make the OEM size tires for the rear.

Continental TS-800 and GT Radial Champiro WinterPro tires are options for snow tires. The Blizzak WS-60's are no longer available in the OEM sizes.

The Vredestein Quatrac 5's are All-Weather (not the same as All Season) tires meaning they have the snowflake symbol making them legitimate snow tires as well. I have the Quatrac 3's on my 2015 ED at the moment (I use them as snow tires) and I love them!
 

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When I went to Discount Tire to install 195/55/15s they told me that the largest tire that the 15"x4.5" OE front rim can accommodate is 175/55/15.

I now have 15"x5.5" rear rims up front and General Altimax RT43 195/55/15s in all four corners
 

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2008 Passion. I went with Tire Rack for winter tires and got same-size rims all around (rear equlivalent) and put on Michelin 185/55-15 X Ice X3. I really like the ride. The -2 MPH on standard wheels/tires is exhaustively documented here. I tried to catch a glance of the ScanGauge and/or GPS to check speed but the closest I can tell is I didn't get any change from factory wheels/tires.

My non-winter tires still have some life, but I'm thinking of making the same or similar move when it's time to replace them. That means getting a second set of smart rear rims for the front or changing all four, but the difference in the quality of the ride is worth it.

Has anyone had to adjust their headlights when going to the larger rims on the front? Mine seem to be doing a worse job and I don't know if it's the adjustment or my eyes.
 

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what brand did you run Jim? would a 195 work or be too much mass for the brakes too handle
I 'll quote something that is on the wall Of my friends tire shop, I think it was from Michelin or Continental....." The brake stops the wheel but the tire stops the car" .

The brakes on these cars are awesome...If you want to improve on it, there are Ceramic brake pads and slotted rotors :)
 

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Discussion Starter #11
tires vs mph

please correct my logic

i figured having oversize tires would not register a faster speed but a slower speed on the speedo (if measured by the front wheels) because the tire circumference is bigger therefor the needle would not be measuring a faster rotation of the tires but a slower revolution

how does the front wheels measure the speed?
 

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how does the front wheels measure the speed?
For a given rpm of the front wheels, tires with a larger circumference move the car further. Consequently, the actual speed will be higher than the speedometer says if the tires are larger than the size the speedometer is calibrated for.
 

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Discussion Starter #13
i can sympathize with you mrbadexample. last year i had a massive infection in my abdomen (i am on dialysis) and they opened me up big time. i layed in icu for a 6 days under anesthesia 24/7 with my innards exposed without being closed awaiting 3 more surgeries rather then closing and opening each time.

i hope you are doing well and wish you a speedy full recovery
 

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Discussion Starter #14
sorry svaraman i must be hardheaded. i still don't follow the logic. the speedo doesn't measure the ground it measures the spinning of the wheel and since the wheel is spinning slower the odometer and speedometer would be less.
 

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sorry svaraman i must be hardheaded. i still don't follow the logic. the speedo doesn't measure the ground it measures the spinning of the wheel and since the wheel is spinning slower the odometer and speedometer would be less.
Let's say that the front OEM wheels and tires are turning at 100 rpm and the speedometer reads 60 mph. You then change the OEM wheels and tires to new ones that have a circumference that is 10% larger. This means that for every revolution of the wheel the car travels 10% further. Now if the wheel is spinning at 100 rpm, the speedometer still reads 60 mph but the car is really going 66 mph (10% higher than 60 mph). That means the speedometer is reading low.

Does that help?
 

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Yes, a confusing situation. the speedometer only measures number of turns of the wheel. so lets say 1 turn of the wheel reads 1 MPH on the speedometer. ( circumference of the tire is 1 mile) NOW lets increase the size of the tire so the circumference measures 1.25 miles. Speedometer will still say 1 MPH but the tire actually travels 1.25 miles. The car will travel faster than the speedometer reads. The radar gun will measure how fast the car is going and even tho the speedo says 1, the radar readout will be 1.25.

If you end up with a smaller circumference tire, speedo will still read 1 mph but the distance travels will be less so Actual speed will be lower.

Another option would be to use an app on your phone that shows speed using a gps and compare that to what the speedo says.

Option 3 is to check with the tire manufacturer (or Tire Rack) and they will give you the difference in MPH of different size tires
 
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