I was just wonering what kind of gas mileage you guys get with your 350's. I'm talkin about emissions legal 350s with stock cam and block (nothing bored or stroked).

 

I'm getting about 14mpg avg city/hwy.
With tbi, 5 speed, 3.73 gears and a lead foot.
-Rich-

 

TBI on a 350 in fbody?
I can't say about 350 mpg cause mine is only 305

 

I'm not sure you should mention gas mileage and 350 in the same sentence. If you have an orginal mileage engine thats never been rebuilt, I can;t see getting much more than 12 mpg. You might get more if you're able to keep your foot out of it. I'm not like that. I'm sitting on too much power to be nice to the gas pedal. I'm probably getting 10mpg or less. My 350 has 150K miles and has never been touched.

 

...just swapped the original (!) O2, and went from a 12 city/15 hwy to ~24mpg hwy (not steady state cruising btw). I have yet to calculate mileage after city running with the new O2. FWIW the car will hit 120K on the drive home from work tomorrow...

This is with a 1990 L98, with the addition of 19lb F0rd injectors, AFPR, Flow Force II catback, lightly ported plenum, and Hypertech cap/rotor/coil. I have the stock TH700R4 and 3.23s out back. My cats now have the death rattle so I am hoping for a small improvement with fresh pipes down under.

HTH, peace

K

 

I'm getting ~20 mpg with my engine in a heinously unaerodynamic BRICK of a van.

I would think that a stream-lined F-body would do better...

FWIW I squeezed nearly 3 mpg out of my stock L05 just from PROM tuning....

 

87 L98 TPI engine. Opened up stock iron heads, airfoil, headers, good wires, AC plugs, 7004R, 3.23 gears, and running rich on a 305 PROM w/ a 870 ECM I manage 14-16 mpg combined about 60 percent city / 40 % highway. Knocked down 20mpg on my last long Interstate run, and that was running 80-85 mph.

Just swapped known good GM ignition parts for DUI cap,coil, rotor and module, have yet to open the plug gap up to .55 as recommended, and I picked up a solid 2 mpg on my last tank with the same kind of driving. And the bad part, I KNOW my injectors need cleaning, and I'm NOT easy on the gas pedal, car is too much fun to drive.

 

Typical EFI 350 expect 13-17 around town, 20-22 highway. I run a zz4 block with everything else stock and in overdrive get close to 24mpg turnpike type driving.

 

I'm getting 14-15 around town with mild mods and engine not even broken in. Up to 20 or more on the highway. And I don't baby it coming off the line...

 

New 350 Crate engine not quite Stock. Depends, around town on how I drive. So here are some averages.

City.....12/13 MPG
Hyw.....20/24 MPG (this is with a avg speed of 70/85 MPH)

Again No two Cars or Drivers are alike,

 

Varys from car to car, My 87 TA 350/ 5 speed I get about 14 MPG
74 Vette 350/Turbo 400 about 12MPG, and 97 Z28 LT1/ A4 about 19MPG all city driving.

 

Dang, there must be something wrong somewhere in my car. I'm not getting anywhere near the gas mileage you guys are getting. Even on wide open interstate driving, my mileage stinks.

 

On my freshly rebuilt L98 I get about 20mpg with 80% highway driving. Nothing is stock except the block.

 

anybody know what i might get with a stock cam, holley 600vs, a holley street dominator intake and headmen headers? oh yeah, i have 3.42 gears too