qaz

Just curious what kind of fuel economy does yall's carbureted ls1's get.

qaz

wow its crazy how many people are on this site. I postsed the post 7 min ago already got 5 views

ZONES89RS

iTrader: (25)

Depends on the combination. Some EFI guys think carbs cannot be efficient, usually they have never touched a car nor tuned their own LS efi setup.

My 6.0, cam, 750 pro form, Vic jr, t56 6 speed and 4.30s was 2000 rpm pushing 76 mph. Would get 17 mpg beating on it and just over 20 cruising the freeway.

Pop N Wood

iTrader: (1)

Get 25 mpg with a 440 HP LS2 in a 240Z. Until I bought my daughter a Kia the zed use to be the most fuel efficient car in the driveway.

Overdrive transmissions and using a wideband to tune allows really dialing in a carb. This isn't the 60's anymore.

sbmalibu

I had a friend build the 550 horse motor build car craft did to the letter a couple years ago and put it in a mustang with a th350 and 3.55 gears. He took it on drag week and got like 18 on the highway with it running 70 or better most the time.

ZONES89RS

iTrader: (25)

That's pretty good for a 3 speed I say. But as long as it is not pig rich, it should be fine.

Get tired of so many EFI Nut huggers that doubt what a carb is capable of when they are usually not even doing their own work on their EFI cars.

89gmcs15

iTrader: (7)

I'm rockin my lq9/ls3 medium/large cam combo th400 with 3.73 and a 26" tire and 3000 lbs loaded up and I'm gettin around 4-6 mpg on the highway. Good afr at wot but alittle rich at idle. Didn't build for economy, built it to smoke the tires

speedtigger

iTrader: (16)

I don't measure my cars MPG, but I do monitor its FPG (fun per gallon). I would quantify that as a whole bunch.

DeltaElite121

iTrader: (1)

I'm curious - are you running annular boosters on your Proform 750?

ZONES89RS

iTrader: (25)

No, just down leg boosters that come on the pro form main body.

cruisin'73

iTrader: (8)

Old thread, but I would like to contribute to the database:

1973 4D Nova
3300lb, plus 300lb w/me+gear
junkyard 5.3 all stock
Mechanical Speed Demon 750
TH350
2.73 rear gear

Averaging about 15MPG bewteen city and highway. But I also run that junkyard motor pretty hard. 80MPH cruise on freeway, moderate launchs from the lights. Based on some of the numbers others are getting I still have a lot of room for improvement. I bet a running a MAP sensor and getting a wideband tune would go a long way!

But like Speedtigger said, awesome FPG economy!

wildcamaro

iTrader: (15)

Carbed 5.3 with proform, 4 speed manual, 2.73 peg leg rear... Getting around 12-15mpg around town but I can't help myself from banging those gears and ringing it out! I haven't even touched the carb yet...it runs good so until I find someone who "knows" how to tune a carb I'm leaving as is...I do wanna get some grandma mileage numbers in the future