gas millage and handling question

[Mr 5 0]

I have a lightly modified '90 LX (5-speed) and I use 94 octane gas, exclusively.

I average about 15-18 mpg, depending on how much around-town driving I do.

I've gotten 24 on the highway (26 on a long highway trip) and less than 10 mpg when driving stop-and-go and/or racing. Gas mileage depends on how you drive it, but a V-8 Mustang is not an economy car and was never meant to be. You want economy, buy a Honda Civic. You want performance, buy a V-8 Mustang. Simple as that.

Mustangs are nose-heavy, have tons of low-end torque and as a rear-wheel drive car, they will fishtail on a damp/wet road or in sandy road conditions. You have to respect that aspect of the Mustang or you're looking for grief and bent sheetmetal.
Obviously, having good tires helps traction.

In the wet, start very easy and upshift quickly. Most Mustang drivers get into trouble when they try to drive in the wet the same as they do on dry roads. Dumb. Some new Mustang drivers think it's 'fun' to fishtail and try it once too often, ending up out of control and in an accident. Also dumb. Respect your cars limitations.