How many mpg in a 4 cylinder s10?

The fuel economy of a 4-cylinder S10 varies significantly depending on the model year, engine size (even within the "4-cylinder" category), condition of the vehicle, and driving habits. There's no single answer.

You're likely to see EPA estimates ranging from the low teens (mpg) to the mid-20s (mpg), but real-world fuel economy will likely be lower than the EPA estimates. To find a more precise estimate, you should specify the year of the S10 and locate the EPA fuel economy data for that specific model. You can usually find this information online through the EPA's FuelEconomy.gov website or sites like Edmunds or Kelley Blue Book.