NEED Better Fuel Economy!!!!

[93formulalt1]

Hey guys, I'm coming to you for more help. I seem to be getting HORRIBLE gas mileage in the Formy. It's not running bad, but I think I may have a couple of issues that could help my empty wallet situation at the gas pumps. . .

First, when the car is running, it makes a metallic whining noise, seems to be coming from something connected to the serpentine belt setup located near the bottom of the engine. Second, when the Heat or A/C are on, the RPM's fluctuate slightly as the A/C compressor tries to kick on. I haven't had the A/C compressor kick on and stay on for more than a few seconds at all this year. I think the compressor might be going bad. Third, I do have ALOT of carbon buildup on my exhaust tips. I'm always amazed after I wash the car just how much better the tips look. They are the stock round rolled edge quad tips that came on the car.

I don't drive it like I stole it, I usually baby it to try to get the best mileage I can out of it. Don't get me wrong, I'll beat on it once in a while, but seeing the issues that I'm having with it lately, I haven't really beaten on the car in a while.

I know it's due for a tuneup, but I'm really not looking forward to changing those plugs and wires. . . As Joel told me at the Meet and Greet last year, it seems that I have a leaking exhaust manifold gasket. Funny story, I almost ordered a set of headers with an ORY last week, but decided it would be better if I put plates and insurance on the Sonoma. Long story short, $350 is gone, the truck is running like sh** already, and I'm still DD'ing the Formula. I'm going to try to get a refund on my insurance for the Sonoma, but I don't think it will happen. Maybe I'll just apply it to the Formula's policy so I can have another 6 months of coverage. I'm about at my wits end. I think I may sell the Sonoma and scrap the Blazer, I'll get about $750-$800 for the two of them, I can get headers and ORY and install them myself, then save up and have the local exhaust shop fab up a new exhaust setup for me. I'd also like to get a CAI, since I haven't done that yet, but I keep trying to get a DD running so I don't have to rack up any more miles on the Formula. She just turned 160,000 Miles on Wednesday. I've had her for a year and a month, and she had 148,000 miles on her when I brought her home. I think it's time for a tune up like ASAP, because the only thing I've done to the car since I bought it is a couple of oil changes and an air filter. . . .

So, I would like to know what my gas mileage SHOULD be now (stock with a flowmaster muffler in the stock exhaust system), and what it should be after I get headers, ORY, a better exhaust setup, and CAI. I'm desperate to break 20mpg at this point, I think I'm getting around 15 (all city driving) right now. I drive about 35-40 miles a night for work, and I'm only allotted a $40 fuel stipend per week. That's 245 miles a week, on 9.6 gallons of fuel. I'd have to get 25.5 MPG just to break even!!!! Not to mention I also respond to alarm calls at all hours of the day and night, so that's more gas used. To make this work, they're either going to have to give me more for gas, or I'm going to need to get better mileage. I've tried to get them to pay me more, but it's not happening. So, it's up to me.

Do you guys think I should sell the Sonoma and scrap the Blazer to finance the maintenance and get some headers? The Sonoma runs and drives, but it will only drive for a short while before it starts having problems. The Blazer is totalled, I was offered $450 for it's carcass by a local boneyard.

Any and all suggestions are much appreciated, as always, and I hope to hear some good ones soon!!

[MP81]

Tune up sounds like it's in order.

Seafoam it.

Opti?

[pHEnomIC]

Im sure Joel knows what he's talking about if he said you have a leaking exhaust manifold gasket, you need to fix that definitely for mileage. A leaking exhaust will screw with exhaust velocity and pump extra oxygen into the pipes causing the oxygen sensors to tell the engine to add more gas. I think the best course would be fix that, seafoam it, plugs, and it is probably your belt tensioner whining. Those are pretty easy to change.

In addition, I would get a clean air filter, clean your maf sensor, make sure you don't have any vacuum leaks, etc.

You don't really show signs of opti, that would be horrid misfiring.

[nascarnate326]

seafoam for sure

[JoeliusZ28]

1) I think you need to sit back and realize that no matter how much money you throw at this thing.... you are not going to achieve the mileage you need with an LT1 formula. For every mod you do, gas is gonna go up just as much. Food for thought.

2) 15 mpg city aint bad for an automatic LT1 with stock manifolds. I honestly dont remember saying anything about your manifold gasket but if thats what i noticed I was prolly right lol. For reasons like jon said, that could explain the carbon on your tips.

3) you can figure on headers/good exhaust gaining you about 2-3 mpg, more if you have a leaking gasket. 4 is definitely possible with duals, no cats, and an x-pipe to get the most scavenging. I got a solid three out of mine. no matter WHAT kind of driving i was doing, it did better. That being said, are you sure you dont just want to get rid of your minitrucks and throw the money at a motorcycle you can get 50 mpg with to offset the formula on nice days? The way i see it you are fighting a winless battle.

4) I would bet that the squealing sound you are talking about is the tensioner pulley. Check it out and if so replace that no questions asked.

5) For a cheap CAI, take out your stock airbox and see if you can find a cone filter that will fit the first half of the stock airbox.

[93formulalt1]

Good suggestions, Joel. I'm planning on getting rid of the minitrucks, but the way I see it is this; Without the trucks, I can't rationalize buying a motorcycle, because then I have TWO summer-only vehicles. A friend of mine has a late-80's Yamaha 650 motorcycle he said he'd sell for $300, so I might do that, but I'd like to get the Formula running a little better first. I'm at my wit's end with the Sonoma, I'm listing it for $1000 on Craigslist, as it is a complete, running (albeit poorly), driving truck. Hell, I paid more for it in worse condition than it's in now.

That said, I've been neglecting the Firebird for far too long. I've driven the hell out of it with the problems it's got, and it really is my main form of transportation. I'd like to fix it now, then buy a decent beater later, probably this fall.

That said, I know of a '94 Firebird 3.4 V6 A4 with less than 150k miles on it for $1500, I was thinking of getting something like that as a winter beater. I got through the snow better in my '94 M5 Camaro V6 than my dad did in his '96 4x4 Blazer, so I wouldn't be opposed to another V6 F-Body.

At this point, any MPG increase would be better than doing nothing at all. I know that the more money I put into the car, it's not going to really help in the long run, but it will help to provide a more powerful and efficient vehicle to use as a basis for my future modifications.

[kammi10]

didn;t u buy a motorcycle a while ago?

[.DetroitKing.]

i agree with the above , if u want mileage dont look at lt1

[Virtue]

i got a nice td setup if you were interested

[Derek]

didn;t u buy a motorcycle a while ago?

that was my first thought.. secondly I highly reccommend seafoam. Just by guessing your car is probably begging for it and it should help fuel economy alot. Full on tuneup wouldnt hurt either.. I dont think you will notice too much of an increase in mileage from doing any mods. Its all in how you drive it and if you are taking off slow from stops etc.. that noise coming from your motor sounds like a pulley going bad which could be the AC one also.. had that seize up on my gfs parents explorer and snap the belt after squeeling/grinding etc all the way to florida. Might wanna check the pulleys and if they sound gritty when turning it probably needs replacing, that is a stab in the dark though.

[badinfluence]

i'm getting 25-31 MPG easily in my S10, might want to fix up the truck

[93formulalt1]

What engine/trans/drivetrain is in the S10? Mine's an Ext. Cab 4.3 Vortec Auto 4x4. That's the lowest mileage rated S-Series GM sold in '94. Plus it's got 209,000 miles on the odo.

A change in my financial situation required that I make a couple of sacrifices, and unfortunately, the motorcycle was one of them.

I know the LT1 isn't exactly famous for it's impressive gas mileage, but I do know that it is capable of gaining a few more MPG's over stock, and that's what I'm aiming for right now. I love to drive my car, and I'd like to to a little more of what I love before I'm stuck selling the car and buying an econobox.

[Virtue]

you can def do better i was getting 18 in the 408 with the stock 10 bolt and steel driveshaft

[badinfluence]

the S10 is a 4cyl / 5spd. for one, 4x4 means nothing because 99% of the time you'd only need 2WD (assuming its not all time 4 wheel drive).

[b.lee]

Go LS1.
I got 26.6mpg last time i went up north, and my car is an auto w/ 3.73 gear
Everyday city driving, 22-22.8mpg

If you get a 6 speed ls1 w/ stock gearing, it should get 30mpg or over on the hwy and 22-26 city.

(I do my mpg every tank, so I know my #'s are nearly spot on)