Here are a couple of points I have wondered about that will be significant in the MPG contest.
1. I've got carbs. If I stay in gear as I release my foot from the gas pedal, does it pull more gas through the jets than at idle? I'm thinking yes, but...
2. Does it make more sense to slowly accelerate to traffic speed, or give it more throttle for a shorter period? My guess is that a lighter vehicle might benefit more from going to cruising mode as quickly as possible. I'm thinking that there must be a balance somewhere between mass and rate of speed increase and WOT consumption vs. cruising consumption.

Anybody wanna speculate?

Jack-rabbit starts, while fun, are never gas saving maneuvers If you want better gas mileage, go slow and steady.

Another way to optimize your mileage is to clean up your engine compartment. A cleaner engine compartment (with all of the tin in place) should run cooler and provide better efficiency. Also take a look at your oil cooler. are the fins gummed up or is there the clean air-flow for which it was designed?

Then, take your lead-foot off the accelerator.

Its physics.
A body in motion wants to stay in motion.
Friction and wind are what slow you down.

You use THE MOST energy/gas taking a standing mass of 2200 lbs and getting it moving.

Think of it like this.
Push the car from zero to 25mph...
Push it from zero to 3mph...
Which one took less energy...3mph did.

So, driving style contributes TONS to your MPG.

On the highway...go 55 (what the car was designed to do) and you will see huge improvements in MPG..
Push in the clutch and let the engine idle instead of using fuel to slow down...use the brakes...again..its physics.

Rich

tire pressure.clean air filter clean fuel filters and short shifts and steady speed will help the most.#1 i say no your off the gas and your slowing

Depends on whether the port is above or below the butterfly. If below, on deaccel, it would be subjected to very high vaccum and it would SUCK ..... fuel. FI rules (no matter what JP says).

I remember seeing an article years ago comparing acceleration from a dead stop and fuel usage.

IIRC, they did a test with a BMW and started from a dead stop by accelerating to a certain speed, then holding that speed, lastly braking to a stop. The tests were repeated with a high acceleration (flooring it), and a gentle acceleration.

The net result was that the low acceleration saved some fuel, but very little. The reason was twofold: First, the engine runs most efficiently at WOT. So the HP output to fuel consumption ratio is higher for WOT than a very slight throttle input. Second, you spend more time cruising at a constant speed in the high acceleration case. Constant speed cruising requires very little gas, as long as the speed is reasonable.

Recently I've started driving my truck a little slower on the freeway (~65 MPH vs ~75) and I've gotten a +1MPG increase. Changing my acceleration habits didn't seem to do as much.

There all below the butterfly thats how carbs work ...you must know that ..I think you been stuck on the FI thing tooooo long.LOL common man your killen me

My work van has gotten ~17.5 MPG since I got it, but to be honest, I dont drive it with MPG in mind. I went to Tahoe last week and filled up there and spent that tank using some hypermiler techniques just to see (air pressure, coasting, shut off engine at stoplights, etc) and I got 22.6 MPG. I pretty much put the van in neutral coming down from tahoe so I'm sure that helped a lot, but I guess those techniques do work.

well, keep accelerating hard and fast, and keep driving fast on the highway....but please join the MPG contest so we can all learn from your results.

Rich

Wrong there Pinky ..... most ports are above the butterfly taking advantage of the low pressure/hi speed stream created by Mr. Bernouli(? ...remember him from physics?) below the venturi. The idle port (circuit) is below the butterfly and will suck fuel under high vacuum.

You need to talk to JP ... he should be in the garage chiseling tires for his parking lot racer as we speak. Ask him to show you the plans he drew up when constructing Stonehenge.

As as far as being around FI to long .... well, we used to sleep in the open and in caves ... we then figured out how to construct shelter ... now you want me to go back to carbs ... which is like sleepin' in the open again.

maybe. ..I just remember haveing to open the butterflys to see if fuel was being dumped ??i look around and see what i find anyway if your off the accelerater pump your not useing fuel except to idle wouldnt that be on the idle jets .hell maybe im all f`d up.but if it did it like you say the motor would never make it to an idle because it just keeps dump`n gas in to itself?.so just to set it strait FI is better but i have carbs so its a must to rib you fellas with FI .......ps i love sleep`n outside

The day of carbetooters is over... It's time to realize our cars led the world in using FI, and reverting to an obselete technology is just stoopid!

Oh, and you 914-6 owners, you're stoopid too!

(This should generate some interesting responses )

LoL I already said FI was better why do you want to cut me like that head..dont be hate`n because your car is slow

What's the basis for this claim? When I bought my first 914 in July '73, the speed limit on Calif. freeways was 65; 70 in some stretches. 3 months later they implemented the double nickel and I couldn't legally operate in 5th gear without lugging the engine. No way was 55 mph the design parameter for the 914.

I don't know that I will do well in this contest. I have thus far only logged 20mpg at best in my 914. Ugh, those carbs are like little toilet bowls!

When you opened the butterflys to see fuel squirt, you saw: 1.) the accelerator pump shooting gas thru the spray bar ... ask yourself why would this happen. 2.) You would have also seen the transition ports or main jets dumping fuel becuase the venturi created a lo pressure area (otherwise kinda known as a partial vacuum) to suck fuel outta the ports.

If the engine is off ... there is no vacuum created ... nuthin's suckin'. Once you start turning the engine over (at starter rotational speed), there are valves opening and closing and pistons moving back and forth creating suction trying to fill the cylinder with air. The idle port is below the closed butterfly and this wonderous suction is SUCKING fuel from the idle circuit port. If it didn't you wouldn't have the bang that make shit go.

When traveling at a high rate of tilt and closing the throttle, the ports above the butterfly kinda cease to flow fuel 'cause their ain't no vacuum or lo pressure area. The port below the butterfly will see very high vacuum and yes, fuel will come out of the idle port, but it's small so you don't get gallons ... you get thimble fulls. As the engine speed bleeds off, so does the amount of vacuum and fuel returns to the normal idle rate of flow.

Lastly, when you turn the key off, there is nothing to make the gas go bang and keep the engine spinning (unless you have carbon buildup that's glowing red which causes the engine to "diesel").

Return Grasshopper to an entity called a Library ... you know the place while you were in school to go meet your GF de' jour instead of studying ... get books and READ.

After you have read sufficient material, you will come to understand the forces in nature that make your car run. Then and only then can you come back here and put forth really inane theories that can be shot down with a spit wad.

Hey Dan ... my 2.0 /4 with FI was doing 27 mpg @ 110+ and 33 mpg at 75 on the Route 66 run.

All Hail Fuel Injection .......

Hey
I've gotten 30 mpg before. It is just a VW after all.

I noticed a significant increase (2-3mpg) when I chose to stay in the far right hand lane....with all the truckers who are using cruise control.

My past life of riding motorcycles taught me how to draft...its not safe, but its amazing...you can sit in neutral on a bike for hours behind a truck...cant see anything but his tailights cause you have to be close enough...

In a car I found similar results, but its not a draft, its just letting the truck break up the wind...if you get within 100 feet or so you can feel the wind turbulance die down and your car stops working so hard.

OK, maybe 55 was not the design criteria, but 75-85 was not either.
My point was that you can increase your mileage purely by your driving style.

Rich

Google "hypermiler" some time, and do some reading. There's a lot of interesting info out there... I managed to get almost half-again the MPG in my yellow car by changing my driving style.

High tire pressures, and slowing down are the keys. Remember, air resistance goes up with the square of speed, so slower is generally better.

There are more advanced techniques that help as well, but some of them I would not try in a 914.

--DD

Well i must seem like a dumb ass to you but im not.Im just not conveying my thoughts very well.I know how it all works! if your costing with the motor off of course your not useing fuel like you would with the motor running.So i`m going to throw in the towel here because this could go on until I run out of fuel.Thanks for your input.P.s i will read up on this

Back in 1974-1975 when we were having the last fuel crisis, I got to look at a car that a guy from the Ford GT racing team made. He made a 60+ MPG Mustang that he let a lot of the press tear up and down the highway for days at a time to verify the cars high mileage......

What did he do?

First, he trashed the gasoline engine for a diesel. Diesels are more fuel efficient.

Second, he put some fairings on the front and a few other aero tricks to try to reduce the drag coefficient... (he used a wind tunnel)

Third, the diesel was rigged to produce max torque at 2500 rpm

Fourth, he put a rev limiter on the diesel so that the RPM's remained ideally between 1000-3000rpm. Less revs, less injections of fuel, better MPG's......

Fifth, he put in a 6 speed tranny to accomodate the low rpm shift points.......

And lastly, high pressure tires....

Yup. The car got 60's flogging it. Not a rocket in a straight line, but it did get great mileage. The mileage was verified by some of the Saturn rocket scientists that I knew back then...

Ken

Well, I run pretty high tire pressures already.
I've got these nifty pod shaped "aero" splitters- from the factory!
My car sounds like a diesel.
I get max torque at about 2500 rpm.
It takes at least 6 tries to find 5 gears.

I'm gonna win!