What's tire size I should have?

195/60/15 is one that's closest to the rolling circumference of the stock tire, so that's what I'd recommend if you want to go for the wider option. Also 195/60/15 is the stock tire size for the Gen2 in some countries, including here in Australia.

 

I am going to 195/65/r15 on my 2006 because I am tired of putting on miles that I haven't driven! At 60 mph my GPS says I am only doing 58 mph with stock tires. I am not sure but I think the 60 series is smaller Dia. than 185/65/r15 so go with 195/ 65/ r15 in order to get your Speed correct! 60 series is slightly wider as well. Not good for roll resistance.? Hal

 

It's rather annoying isn't it? I'd do the same but I don't want to increase rolling resistance.

I wonder what going to a 185/60/15 (Continental ProContact with EcoPlus) would do. The diameter goes from 24.5" to 23.7 inches and revolutions per mile goes from 848 to 877 when compared to my 185/65/15 dB Super E-spec tires.

On the otherhand, the car knows that it is going 60mph even though the dash reads 58mph. The ScangaugeII confirms this.

 

The tires I chose are not available in the 195/65/15 size, so I went with 195/60/15. The differences in handling and safety are so significant that I consider any little discrepancies in recorded speed and mileage to be irrelevant. My wife has tested the calibration up to 137 kmh, and the speedo seems quite accurate.

 

Is your name based on being 1/2 Asian 1/2 white?

Yout didn't make a good choice for new tires. Not only did you buy a tire not rated as low rolling resistance, you also went with a wider tire. This will definitely drop you mpg. All new tires will drop your mpg a little until they break in but once broke in your mpg usually comes back or gets better if you get the right tire. New tires are usually slightly larger in circumference than your old tires if the old ones had a lot of miles on them. This will effect the odometer slightly and measued mpg may decrease.