How can I get more mpg??? I got an Edelbrock air cleaner and headers coming out of a single exhaust pipe. What else can I do to increase mpg?

 

Buy a honda

 

The 305 TBI cars got the best mileage out of all the 3rd gens. Mine was getting 30 highway before I yanked it out and went to a carbed 350 (and cut that in half).

Another option (my current daily driver) ... 2 wheeler - I commute 110 miles a day on my 1994 Honda Magna getting about 45mpg!

 

I would do anything to get better mileage. I was getting 10 with a 750 edelbrock, and now get 14mpg with a 600 holley.

About to buy a 250cc ninja for 60-90mpg, something that won't kill me going to college.

 

I doubled my MPG when I upgraded to the t56. I also plan to move to an aftermarket fuel injection with a closed loop O2. I already own a Holley projection system with the closed loop not installed. But I think I am going to get rid of that to get something that is easier to program. I would sell it for around $500. It is the 700cfm one that supports up to 400hp. Good luck. The basics are better flow in and out of motor, air fuel mixture improvement, then gears... Looks like you already addressed the in and out. Is your air filter gauze (K&N)? Sometimes looking into brake drag or wheel bearings can really make a difference. Low rolling resistance tires are good too, probably not on a camaro though. They work great on m 4 cylinder 07 malibu. All ideas.

 

just make sure she is tuned up well, kick the timing up a couple degrees to get a little more bottom end oopmh so your not constantly hammering the throttle down. 2.73 gears should be in the car so your okay there. You can do things to lighten up the car which will make it lighter which will increase MPG. if you have big wheels get stock wheels to lighten back up. dont carry uneccesary weight etc..

 

Altering your driving habits would be the least expensive way to increase fuel economy. You can do stuff like let off the gas, or even put the car in neutral when you're close enough to coast instead of staying on the gas and then braking. When you're coming up on a stop light, if you time it right, you can coast for long before you get there and if the light is short enough, you might not even have to come to a complete stop. Do your best to keep constant speed, and not accelerate and brake all the time.

 

I can totally understand wanting to get better gas mileage, who wouldn't. I was told to get better gas mileage drive it like a Cadillac and as if you had a hot cup of coffee in your lap . Some of us like myself that are carrying some extra weight (tools/etc.)and running 3.42 or higher gears and having fun with them, spending more on gas just comes with the territory. This whole site is basically dedicated to getting worse gas mileage not better.(bigger/faster/stronger/etc.)

 

Always drive with the wind instead of against it.HAHA

 

Taking the car out of gear and putting it in neutral creates worse fuel economy than simply leaving it in D or OD and coasting with engine braking for most cars.

With my LT1 the injector pulse width drops to just about zero on deceleration with engine braking. Was reading the data logs the other day.

 

Oh... oops. I was figuring that if the transmission was put in neutral soon enough that the engine speed reaches idle speed, it would increase fuel economy. Thank you for correcting me. I would usually coast for a 1/2 mile before I got to the light coming out of my neighborhood that is always red, and in neutral, the engine would be at idle speed by the time I got there, so I figured that helped... I'll try keeping it in OD and see what happens. (this is all in a different car, as my firebird is currently undriveable)

 

That is really interesting! I would have assumed what "asdfg68plus1" said was right, but I never would have even thought to look at the logs. Awesome catch. I will remember that for when I upgrade to fuel-injection, but what would you think about a carburetor? I would think the shift to Neutral idea would still be correct on that side, but I am not really sure now? What are your (Anyones) thoughts? I have a carborated (holley 750 vac secondary) first gen small black 350.

 

When in the city, shift manually into third, and don't burry you foot into the pedel all the time. Get an open air filiment (cleaner, filter, the shiny thing that sits on the throttle body, etc...) and better exhaust helps because then the engine isn't having to work as hard to suck in and push out air.

 

Shifting the car manually into 3rd wont' help economy jack squat. Leave the shift alone.

The only performance reason to put a 700r4 into D instead of OD is when drag racing. "D" applies more line pressure than "OD" does. In all other cases having the car get into OD is better if you are going to be in the 40mph+ range.

It won't help fuel economy.

 

An open element air filter is no way to improve economy. You're just sucking hot underhood air. Get the dual-snorkel air cleaner from an L69, either F-car or Monte Carlo, '83.5-'86.5

For you guys running non-computer carbs, get a wide-band exhaust oxygen sensor with gauge, and tune your cruise to between 15:1 and 17:1. EFI cars cruise at 14.7:1 for emissions reasons, but 17:1 is no risk.

 

To the best of my knowlege it does help. Why does/doesn't it help with fuel economy? I'd like to know the hard core facts sence I just keep on getting peoples opinions.

 

Its an automatic transmission. It doesn't shift into OD until ~43mph anyways, and the TCC lockup doesn't occur until ~47mph.

So for driving anywhere below 40mph the trans will stay in D on its own, no need to put the shifter in D.

There are a few reasons to put a OD trans selector into D instead of OD. Among those reasons are towing and drag racing. When towing D keeps the transmission in a better gear to tow at speed. This is especially true with a light duty SUV/truck like a Blazer or Ranger.

Another reason is that D applies more line pressure than OD does. So its ideal to use it in drag racing as it reduces the possibility of slippage occurring in 3rd (D) gear. The 700r4 will do a far better job of shifting than you can. This becomes even more true with a nice shift kit like a TransGo shift kit.

 

I see.

 

The whole idea of efficient engines id getting the most possible energy out of each drop of fuel. Wait, drops come in all sizes. Anyway, a cooler charge is denser, so your dynamic compression goes up. But you're cruising for MPG, so you're still well under the dynamic PSI you'd have at the same RPM at WOT.
Upping the dynamic compression, to the detonation limit of the available fuel, will get more energy from the fuel. This is why diesels are inherently more efficient.
We can't do it in 2011, but in a perfect world, your dynamic compression at cruise would be just as high as your dynamic compression at WOT. But variable static compression is still a new technology, and not at all applicable to the SBC.
The closest we can get is Rhoads lifters. But you'd have to tweak the whole combo to take advantage of them, and the cost of their HR version isn't low, it might take an awful lot of miles to recoup your investment.

 

Also good spark plugs to burn fuel efficiantly

 

my carbed 305 got 24mpg on the highway. My built 350, headers, 3" exhaust, shift kit car with the same gears (3.73) gets 18 on the highway...with the cruise on at 70. Your TBI 305 should be way better than that if it's tuned properly.

 

Only bringing this slightly back from the dead. I actually was cleaning out my website of left-over files when I found a datalog recording of two drag runs I did at Cordova Dragway in IL. As a note, this run was before my LT4 knock module which was picking up false knock from the headers. The LT4 knock module fixed the 4-5* constant timing being pulled.

On decel with engine braking on the PCM stops all fuel flow. BPS mS is the injector base pulse width, in milliseconds. Basically it is the length of time the injector is commanded open. More time means more fuel. Its located on the left table about midway from the top.

You can see it when I'm coasting down after the run, the BPW goes to 0. This means the injectors aren't being commanded to fire at all, no fuel flow.

http://www.youtube.com/watch?v=4xjdXxGafIs