How bad is 205/40/17?

[Fryguy]

www.wheelmax.com has weekly specials for pretty good price (500-600 for wheels and tires, mounted and shipped to your door), however, 99% of the time they are 205/40 tires instead of 215/45 or 225/45 like is usually recommended on this forum.

a. how much will this throw my speedo off (a link to a calculator would be fine)

b. would it be particularly bad to run this size tire? It's either this or I'm just going to buy new stock 14" tires. There is not much time for me to save up (these tires are BALD, and I need to swap before it starts getting slippery up here in new england.

c (somewhat related to a). How much will this lower my car?

 

[JEDI]

I have ICW DV-8 Rims with 205/40 17 Kumho 711 tires. My suspension is stock.

the car rides fine but you will notice your speedometer off quite a bit. At highway speeds it gets to be around 5 or 6 mph. More over, if your car isn't lowered, it just doesn't look right.

I wanted to go to 225/45 myself but found out the hardway that either 1. They won't fit 17x7 rims or 2. My tire place simply doesn't know what the F' they are doing. I have some pics I can e-mail you if you like.

 

[Defiant]

http://www.miata.net/garage/tirecalc.html

 

[Fryguy]

My car is lowered and on shocks, so the suspension isn't an issue. I was just curious if the ride quality was bad because of being extremely low profile, or if there were any other adverse effects.

BTW, thanks for the calc.