I want to know what gas milage everyone is making with TBI, especially the 350 guys. Who has the best/worst. I made 25.9 highway 20 city with 305 and 2.73. Then downgraded to 22.9 highway 18 city with 350 and 2.73's.Now at like 19-20 highway with 3.42's and who knows what in the city but it can't be good.:rockon:

 

Do a search on the topic-it comes up all the time. My 305 use to get about 23 mpg before gears and throttle body and chip. Since then, my converter has decided it doesn't want to lock up any more, so until I get the t-56 in there, i'm lucky if I get into the teens.

 

10-12mpg in the city and 20-22mpg on the freeway. I need a chip.

 

My mileage depends on temperature, humidity and driving habits.

During the hot humid days last few weeks I was getting 18 mpg city.

On cold/mild low humidity days I get 22-24 mpg city (mostly traffic dictates my milage though so on really crappy days of gridlock it goes to hell like 15 or worse)

On highway, pure highway I get 28 mpg avg.

 

10-14 city (lead foot) and 22 highway. That's with 3.73 gears and everything in my sig.

 

15-20 city mpg, 25-30mpg hwy with my setup depending on how much I stomp on the gas.

 

I'd say my mileage is 14/19 or so (3.42s)....keep in mind vehicle weight

 

24-25mpg normal driving some city some highway

28-32 mpg highway

 

mine was about 15 city with TBI nows its about 12, but when the primaries are open the secondaries are too(HEAVY FOOT)

 

I can't remember highway but with city I got 20-21mpg. I know stock for our LO3's is 17mpg city but I think by getting rid of my cat, upgrading all of my ignition and not flooring it all the time ( ) helped a lot. That was with 3:42's too so not to shabby.

 

I get 15 mpg city summer, and about 20 highway.

 

when i had tbi on the 350 i was getting around 22 on highway was horribly off tune and in city i never mesure in fear of the truth of the gas mileage i made :P

 

I get 17/21. I measured 21 mpg on the hiway with an entire apartment full of furniture and stuff in the back of the van...that was also going 80 mph.

Hehehe...I also have the aerodynamics of a barn

 

I get about 15 city and maybe like 23 highway. Thank you NJ traffic!

 

I average about 16-17 in town,20-23 on the highway.

 

Xfire Vette. 95K miles, 340hp, 3.07 with 4+3. 24mpg @ 80mph.

 

200-220 mile a tank u do the math.On the 350 300+ on the 305
. i miss having a 305 in some ways

 

With the 305 and 2.73's, I got 19city/28hwy unmodified. After I gutted the cat and installed a 3" cat back system, 21/30. After I did the ultimate TBI mods and installed a 1/2" phenolic spacer, 20city/27hwy.
Mileage hasn't changed much, but power has increased steadily!

 

15-17 mpg in the city

26-29 mpg on the highway

and yeah......that is with the hang glider on the back on my car