I own two toys,and one is a toyota. one goes about 80 max (just sorta stops accelerating about then) and the other goes 160, i figure its a good combination. I havn't checked th mileage since the new tires, but i have noticed after a basic tuneup ($60, cap, rotor, timing, idles, and vacuum lines) It has a bit more power on the highway. I'd say replace all your vacuum lines if you haven't, pretty cheap insurance for both proper economy and performance.

86 4runner, pro comp AAL, Kayline Soft top, 31's but all stock