My 81 Z28 project has the bone stock 175HP 350 engine, TH350 trans and best I can tell, 3:42 gears. I was wondering if anyone may have an idea on what I can expect at the pump. I had an 80 RS with 305 and got outragious mileage. But didnt know about the 350.

 

1. Fill your tank.
2. Reset the trip odometer.
3. Drive until it is time to refill again.
4. Look on the fuel pump or on your receipt to see how many gallons it took to fill up your car. Write this number down.
5. Look at your trip odometer to see how many miles you drove.
6. Take the miles driven and divide it by the gallons used. This number will by your MPG for that tank.
7. Make sure to reset the trip odometer again to calculate the next tank and compare.

This is what I do. It doesn't lie.

 

O, I knew how to do that, problem with that method right now is Im prolly at least a year out on even having it to where I can even drive it on the street. I was just kind curious if anyone else had this combo so I could just have some sort of idea. My car only has 27k original miles on it but where its set and the T-tops leaked, it rotted the floorboards completely out. I took the engine out and cleaned up the engine compartment and all that and just did a basic gasket replace on the engine where the gaskets were leaking. I was leaving it stock for now just so I could enjoy driving it on a nice summer day without killing the wallet. Later on down the road I will definately think about another motor.

 

8~20 is a good ball park. for both city/freeway. depending on rear end gears. jetting, how you drive it, tire size, smog garbage that doesn't help much. most 2nd gens are around there. but they arent like newer F bodys with 13gallon tanks.the 2nd gens, they take some $ to fill. but if u get the same mpg as a new Fbody they rock. my V6 gets about 24mpg in my 98. 13gallon tank goes about 300 miles. my 305 in my 79 was haveing some rich problems when i was drivein on it so it probly went a 300 miles on a tank to. its all in what ur looking for.

things to improve it. is pretty much gearing. 4 speed trans with freeway gears helps alot. tire size helps a little. and not wrompin on it im sure u could get in the 19~20 zone and higher. (dono what people with 4 speed trans on a 350 would get) our pickup gets 18 but then again its heavyer. just some ideas for yeah hope it helps.