Okay, due to a recent post bring up carb vs tbi I just thought I would ask, what's your gas milage?
Mine is 23 highway with the 330hp crate motor, 4L60, 2800 stall TC, Holley 670 w/ open element, and 3.73 posi gears in rear.
I can't remember my stock milage but it was slightly better, 25 sticks in my mind, that was with 3.08 peg leg and heavier.
I understand carbs can run great but it's not as flexible. There are a lot of things a carb can NOT due, one of those is safely run a highway mode. From tuning these pas few years I've noticed more and more how bad even stock cars are tuned. This is in reference to cars in the 80's and early 90's, today's stuff is great but still lacking flexibility.
I'll have a city milage figure next time I go to the gas station which will be about 8 gallons from now.

 

with mods in sig, and lots of tuning with the hi-way mode in the chip. i get right around 30mpg on the freeway with 3.42's.

 

With new engine and rest of combo in sig, except with 1.5 rr and performer intake, I was making 25-26 highway, however, my blms were really bad when cruising, in the 112-118 range.
Car will be up and running soon with the airgap intake and 1.6 rr, I hope to get 26-27mpg highway after she's tuned. Just waiting on the new hood to arrive....

City milage sucks though, I would guestimate low teens.

 

LOL, do note i didn't mention city milage but having a 5speed with the long overdrive gear. and hi-way mode tweaked pretty good, on the commute to work i do well, stoplight to stoplight however, i am in the teens.

 

With stock heads and cam and tune plus mods in sig I pull 25-30 on the highway and low teens in the city. My LT1 pulls 28mpg all day long at cruising. I think it is funny how one of my cars has roughly 100hp more than the other one and pulls better mileage.

 

With the engine, gears, and mods in my sig. I can only muster about 20/21 mpg highway, and close to 12 in the city. I have right foot issues and feel it is important that my mule leave the line before anyone else.

 

I dont know exactly but its terrible

wb o2 AFR of around 12.5 ALL The time, just off idle so im pretty sure its not my primary jetting. Maybe my transfer slot is too big or something? Dont really care too much since I dont need to drive anywhere. I will be remedying this with the tbi though

 

350 TBi w/ vortec heads and 65# injectors, stock rear end gearing, stock T5 and all emmisions equipment:

City: 18.5 to 19, Highway ~27.

The city driving has been confirmed repeatedly over the course of about 8 full tanks of gas. The highway driving was a ~270 mile round trip up to Wisconsin and back- mostly 5th gear.

Also, the city driving has included a trip to the dragstrip and multiple street brawls, burnouts and generally poor driving behavior.

S-D

 

Well my stock, minus the tibchips.com chip (more timeing and a bit of fuel, no limiter, no vats) manages around 26mpg (at 85mph) and about 27-28mpg at 70mph. Have hit almost 30mpg with a slight tail wind at 65mph. Around town, if i am easy on it, i am hitting almost 21mpg. Not bad but then again as many miles as i am covering these days 40mpg in town would be better.

 

COMBINED CITY AND HIGHWAY 17.50 MPG. TUNING NOT YET OPTIMIZED. 11.5/1 IN PE MODE.

 

With the setup in my sig and timing at 6* BTDC, I get 28-30 highway and 20 average.

 

My '92 gets about 21 city/hwy combined. It's pretty much stock.
16.5 ET @ 82.8 MPH

My '72 Camaro isn't bad for a carb.

Old 350 with worn rings (enough blow-by to cover both valve covers with oil EVERY time I drive the car), Vortec heads, 280 Magnum cam, Performer intake, Holley 650 DP, 3.42 gears, 25.6" tall tires, TH350 w/ ~2400 stall, and kissing 3000 RPMs at 65MPH........

I get ~13 mpg city/highway combined.

G-Tech says 14.2 ET @ 103.5 MPH. That's probably more around 14.5 @ 101-102 MPH on a real dragstrip since G-Tech is a little "generous".

I don't know for sure it's a 280 Magnum cam. That's my guess based on what little info I got from the previous owner.

I have no idea what static comp. is, what jets are in the carb, or what the actual advertised stall of the converter is.

Once I get the 350 replaced, it'll be a little more efficient, I hope.

 

i get around 12 mpg in the city and aropund 26mpg on the highway.

 

With my LG4, T5, and 3.42 gears I was getting about 26 mpg combined highway/backroads to work and home in the SC. It should do better in the Formula as I've swapped in higher overdrive gears - went from the .73 down to .63:1 to lower cruising RPM.

Pete

 

my 86 carbed Z28 would get just short of 19 around town and 28 steady on the highway. It had a scummit 204/214 cam, stock qjet, modifed secondary stuff, edelbrock headers.... stock distributor, and computer. 700 and a 3.42 gear set.. it was great on the road. ran low mid 14's down the track.

My stock 305 tpi 5spd formula.. with 3.45 gears... runs mid 14's down the track.. with all the original stuff and gets 16 round town and 23-24 on the highway..


The Z28 now... i have no idea what it gets mileage wise it rarely goes farther than 10-15 miles at a shot.. mostly 1.5 miles to the drag strip and back.

 

City mileage can differ so much I don't see the point of saying it, but anywhere from 10mpg-15mph in the city...

On the highway if I cruise at 65 mph I can get 20 to 21 MPG. Carbed 355, 700R4, 3.73s...

 

15-17 in town,20-21 on highway to work,and 23 on long comutes.Allstock exect an open element and flowmaster exuast.

 

I need tuning then.

8-10 city
17 with mixed city driving and long, fast, highway runs. (70 miles at 85-90)
20 All highway 80+

 

I get 16 mpg in the city, average (with the 5spd). I have no clue about highway. Will I really see 30 mpg? How about with the T56? I'll have 3.73's in a month or so.

-Rippin

 

So you have the 6-speed in there now? I have 3.73s and a T-56, and actually make better gas milage at 80mph as opposed to 65-70mph. Of course at 80mph, I'm only at 2,000rpm. I'm sure with the 1.6 rockers and airgap intake my power band has moved even further up......time for 4.11s...hehehe

 

i have a 91 firebird, with a bone stock 305 TBI and i barely pull 12-15 MPG city and 18-20 H-Way , no clue why..... but that should make all the gas guzzlers feel better, un less one fo the huge gas guzzlers wanna offer any advice, cuz i can't seem to fix it. EGR is about 2 years old timing is dead on at 0* without EST and with it is about 6* advanced at idle. Any help would be awesome if not enjoy having better mileage then a lil bone stock 5.0L!!!

 

Burn your own eproms and get rid of EGR. Tune your vol eff tables and open up the exhaust. That's what it takes for good milage. Take a lesson from the newer cars, exhaust FREE, intake is your restriction, work on that after you get your exhaust free. That's gas milage, oh, and a good dual pattern cam with awesome heads like vortec or AFR. Gears enough to keep your engine from bogging down too low and requiring lots of throttle. 3.42 gears is a good start with an auto for average driving around town.

 

with an open element, and new fuel filter, i can pull about 320 on the highway and about 150 in the city, rest of the car is stock

 

man i would get rid of the egr and A.I.R. only problem is htis is my daily driver out here in California... damn emissions are a huge ticket....

 

"mods" same as sig...

I had big issues with a leaky injector o-ring, ignition, wheel bearings, breaks, puel presure and so forth.. 16.4 @ 133km/h..
low teens in milage..

fix all the problems above (exept right whell brearing) and now i get:

12l/100km = 19.6MPG in the city
8l/100km = 29.4MPG on the freeway

In the city i drive the car like it was desinged to.
Keep the ricers in their place.

Now i got all of thouse fixed and a friend drove my car in to the
curb and destroyed 2 tires and 1 rear rim

Its funny. 200-250hp civics/other japanies cars have no chance going light to light (guess its tq)

Even though my car is slow in comparison.