Anyone with a 350...whats ur gas mileage?

[Twizted_3KGT]

I calculated today that my average gas mileage in my '88 Formula 350 is 10.9 mpg!!!! It's completely stock, and that's with me flooring it maybe once for a couple seconds (it's my winter car so I drive like a grandma). Anyone else doing this badly on a stock motor?

[viperh]

Originally Posted by Twizted_3KGT

I calculated today that my average gas mileage in my '88 Formula 350 is 10.9 mpg!!!! It's completely stock, and that's with me flooring it maybe once for a couple seconds (it's my winter car so I drive like a grandma). Anyone else doing this badly on a stock motor?

32 on the highway. 20-ish in the city but I can't keep my foot off the gas especially with the cutout best I got was 23 city. Cutout and Fast toys ram air.

[chevcamaro_86]

its a 350 what do u expect? i also own a 3.1l v6 that manages to get 15 sometimes i think it also could be an emissions sensor is it carborated or fuel injected?

[Twizted_3KGT]

Originally Posted by chevcamaro_86

its a 350 what do u expect? i also own a 3.1l v6 that manages to get 15 sometimes i think it also could be an emissions sensor is it carborated or fuel injected?

Well I expect it to get something close to what factory said of 17-22 mpg, even with 130k. It's fuel injected, '88 350's only came fuel injected. I was just surprised it was that low, I was guessing around 15, i'm not really interested in making it better, just wondering what others with the same motor and around the same year are getting nowadays.

[2.2 Straight six]

haha, be glad it's not like my mate's truck (blown 572) he gets 2mpg when he's having fun!

[chevcamaro_86]

i have a buddy that gets 6 so be grateful

[Twizted_3KGT]

Originally Posted by 2.2 Straight six

haha, be glad it's not like my mate's truck (blown 572) he gets 2mpg when he's having fun!

At least he CAN have fun...I floor it and get a good half second kick into the seat and then might as well just stop flooring it cuz the fun's over lol. Maybe i'm just too used to my other car... 2 mpg is crazy though!

[ZL1power69]

Originally Posted by Twizted_3KGT

I calculated today that my average gas mileage in my '88 Formula 350 is 10.9 mpg!!!! It's completely stock, and that's with me flooring it maybe once for a couple seconds (it's my winter car so I drive like a grandma). Anyone else doing this badly on a stock motor?

my 305 4bbl/5 speed iroc got about 10mpg city on 93 oct and a bit less than that during the winter. thats with free flowing intake, dual exhaust, and 3.73's out back. if you do alot of stop and go city driving that will kill mpg. but remember it is winter and the winter gas formulas that are in use right now always hurt mpg. is your performance suffering at all?

[97cavalier]

probly more like 2 gallons per mile,lol

[92zcamaroperson]

always take care of the little stuff because they can make big differences in your mileage. o2 sensors, spark pugs and wires, for you maf sensor if im not mistaken, etc. I get about 15+ city and whatever it is highway. everyones driving style is so different and everyone here im sure does not lightly drive their cars so youre asking the wrong group of people lol

[Morley]

I have a 91 Formula 350 and it gets up to 25 highway and arounf 15-17 city (depending on traffic). I would suggest a major tune up, plugs, wires, cap, rotor, set timing, replace air filter, O2 sensor, PCV valve, check tire pressure, check all hoses for vacuum leaks and put it on a scanner while driving to log the BLM's.

[poormillionaire2]

All my driving is pretty much city, and on my stock LT1, I averaged about 13mpg and 14 tops without putting my foot in it. But I now get 15 with my added bolt-ons and no tune for them. I have no idea what I get highway, I'm hardly on the highway.

[Twizted_3KGT]

Originally Posted by Morley

I have a 91 Formula 350 and it gets up to 25 highway and arounf 15-17 city (depending on traffic). I would suggest a major tune up, plugs, wires, cap, rotor, set timing, replace air filter, O2 sensor, PCV valve, check tire pressure, check all hoses for vacuum leaks and put it on a scanner while driving to log the BLM's.

All of those were recently replaced, including ALL the vacuum lines (got bored one day over the summer).

I have no idea if my performance is suffering, I have really thin tires on the back...great on snow, bad for flooring it...we'll find out when spring hits and I take it to the track as is...except with summer tires.

I do know this though, when the engine is cold (<30*F), it doesn't "like" to be given a load. It'll actually backfire once or twice if I get on it before the engine has ran for a couple minutes.

One thing someone mentioned that caught my attention is the MAF. I've had an intermittent MAF circuit open since I bought the car 6 years ago. If I remember right, last time I checked one of the pins was bent. Haven't been getting the CEL lately, never really noticeably affected driveability, so I never bothered replacing it...so that'd probably be a good starting point.

But i'm not trying to solve this, $30 a week for gas is better than my summer car gets so i'm not complaining.

[silicon212]

Check the EGO sensor, this could cause a rich condition if it's 'lazy' - failing but not enough to set a DTC. Another thing that I've seen contribute to poor economy in city driving is a failed torque converter - if the car seems like it has no power until it's up to about 25-35 MPH, this could be the problem, especially if you hear a 'clicking' sound from under the car at the lower speeds.

[2.2 Straight six]

Originally Posted by 97cavalier

probly more like 2 gallons per mile,lol

haha, probably is on full boost.

Top Fuellers use 60 gallons in a quarter mile!