One, its illegal to run fast on comfort tires which are all speed rated at less than 100 mph.
The "comfort" all-season tires I use on my Volvo are V-rated, which is 149 mph.
The cheapest of the cheap family sedan tires I've seen are S-rated, which is 112 mph.
To find tires with speed ratings under 100 mph, you'd have to be looking at either winter-only tires or some very, very, very cheap light truck tires. Or, possibly, for some ridiculous reason, be running temporary spares on all four wheels.
As for the tires in the game:
Comfort Hard tires in the game correspond most closely to something like the Bridgeston Insignia, Ecopia, and lower portions of the Turnaza tire lines. These are tires with a treadwear warranty of 60,000 to 80,000 miles and that carry speed ratings between S and H (S = 112, T = 118, H = 130).
Comfort Medium correspond most closely with the higher-end Turanza and low-to-middle-end Potenza all-seasons like the G019 Grid and the ER30. These are tires with 40,000 to 60,000 mile warranties and speed ratings between H and W (H = 130, V = 149, W = 168).
Comfort Soft correspond with tires like the highest end Potenza all-seasons and the beginnings of the summer-only Potenzas like the Potenza RE970AS or the Expedia S-01, which typically have treadwear warranties only up to 40,000 miles and have speed ratings from V to Y (V = 149, W = 168, Y = 186).
Sport Hard are high-performance summer-only tires like the Potenza S-04 Pole Position or the Potenza RE050, which are useless in snow and are horrible below about 50 degree Fahrenheit when used on the street because you can't get enough heat into them to make them effective. They carrying ratings of W or Y.
Sport Medium are the ultra-performance summer tires, the upper limit of what you would ever want to use on the street, and represent tires like the Potenza RE-11 and RE070 (the latter being the actual OE tire for the Lexus LF-A). They are hard as rocks when cold and stick like hot tar when hot and you're usually lucky to get 20,000 miles from them. They also tend to carry W or Y ratings, though some here, as with the prior category, are also rated "(Y)" which means that they are rated in excess of 186 mph.
Sport Soft tires represent DOT racing tires or "R-Compound" tires which are essentially slicks with just enough of a groove for them to be technically permissible for street use. These tires are NOT used on cars driven regularly on the street and are typically the realm of cars that are only street driven in order to get to the track. These tires often don't even carry an official treadwear rating (much less have any sort of warranty). Some of these don't even carry specific speed ratings, instead falling back to the now-outdated "Z" rating meaning simply "over 149 mph." Others carry "W", "Y", or "(Y)" ratings.
Racing tires, of course, represent racing slicks with varying tread compounds, with hard lasting the longest and soft gripping the best.
