Onyx Z

iTrader: (3)

I hear of people getting upwards of 25 MPG in the city with a cam. I still have the stock internals and I can only get 20 MPG on the highway!!!!! Could it be that I have 86,000 miles also or what b/c I really need more MPG. Could tuning be an issue too.
(I had no idea where to post this)

Cal

iTrader: (1)

I doubt you will ever get 25 MPG city with a fbody. I get 20 to 23 mpg combined city/highway depending on how I drive. A cam will hurt your fuel economy, not improve it.

Onyx Z

iTrader: (3)

I don't have a cam though and I can barely get 20 MPG on the highway with a 6 speed car!!!!!

Cal

iTrader: (1)

How fast do you go on the highway, and do you set the cruise or speed up slow down a lot? Air drag varies as the square of velocity; i.e. doubling your speed increases drag by four times.

But if you think there is something wrong, give your engine a tune-up and take some Atap readings.