60-50mph Pulse&Glide with Draft vs. 60-40mph Pulse&Glide without draft

[bhazard]

That's pretty good, for a non-aero-modified Festy.

Had a bike rack hanging off the hatch with two mountain bikes. Maybe that helped? LOL

[mikeyjd]

Had a bike rack hanging off the hatch with two mountain bikes. Maybe that helped? LOL

Ha! It sounds like you might have 55 without them.

[TominMO]

i should have specified that i was in Scrappy at the time (B6 swap with cam)... i did get 44 in the 93 sport comming home from Ohio at 70+ and 42ish in Bruce with the a/c on (same trip and speed)....

Yeah, my B6 gets 42 too. At 60 MPH, no truck to follow.

[TorqueEffect]

I get at least 40MPG going 65-70mph

Highways around here are hectic, I refuse to drive below 65 because it just feels way too unsafe to do so, hell even at 65 I always have people riding my tail.

40MPG is better than like 95% of the cars on the new car market, so I am happy with that. No point in getting myself killed just to have more than that. Though I do try an draft semis whenever I can, but I give enough room to where I feel that I could slam the brakes, or evade to either side if something were to happen.

[sketchman]

Cool stuff.

[Charlie1717]

I see how you can compare the two techniques to see which may work better, however I don't think it would be fair to claim this as a true MPG being you only put in .7-.8 gallons. The inaccuracies of small fill-ups will change your numbers quit a bit.

[mikeyjd]

I see how you can compare the two techniques to see which may work better, however I don't think it would be fair to claim this as a true MPG being you only put in .7-.8 gallons. The inaccuracies of small fill-ups will change your numbers quit a bit.

If you read what I wrote you'll see that I didn't claim that the numbers were accurate, but rather a possible indication of increased efficiency from different techniques.

[drumnerd33]

There is a mythbusters episode that they do a whole test on drafting a semi. The results were it does work but in order for it to work you have to be dangerously close to the back of the semi... for example look at nascar, when they are drafting they are within 1 foot or so of the car in front of them. I do think it would be easier to draft with a festiva because of the weight difference but i think you would have to still be pretty darn close and remember if you cant see the truckers mirrors... he cant see you, please be safe out there.

[drumnerd33]

Also to have accurate mpg# you really need to do at least a half of a tank or more and best is to refill with the exact same pump you originally filled with. Another thing that can mess up numbers here is what size tires you are running? If you are not running a stock size tire then your odometer will be off so gps milage would be best used... lol sorry i have got pretty detailed on checking my mpg. my 88 carb with weber swap, stock motor and 185/60r14 tires and 4 adults in the car doing average of 75-80 mph got me average of 36 mpg which was really good. But if i would have been using my odometer for mileage i was showing like 32mpg which i knew was not correct thats when i used gps instead.

[Charlie1717]

If you read what I wrote you'll see that I didn't claim that the numbers were accurate, but rather a possible indication of increased efficiency from different techniques.

I was referring to including them in your average mpgs in ecomodder. Small fills will give an inaccurate average.

[mikeyjd]

I was referring to including them in your average mpgs in ecomodder. Small fills will give an inaccurate average.

I disagree completely ^ Small fills will make little difference to the overall mpg average since it takes the total miles traveled vs gallons used. The tank before my first 2 highway tests was 55mpg over 140 miles. If you include the 2 highway tests with that 140 miles it averaged out to just a little over 60mpg

[rmoltis]

Also on the freeway something you guys should know.
The more weight you have the better your car is at maintaining a certain speed.
The weight stores energy as forward motion and when approaching hills
while on the throttle it will lessen the rate which speed falls thus maintaining speed and using less gas in the average.
I used to do half tank fillups in Washington because I did so much freeway travel the weight used to help keep me moving forward.
And gave increased avg mpgs.
Not to mention the readout on the scanguageII giving accurate readings from the ecu.
So it is not that it is innaccurate its better with the weight on freeways I think most people don't think of this small fact.
It's almost the same purpose as a heavy flywheel and how it stores energy.

If you drive in the city a ton stop and go where you can't maintain velocity/momentum.
Then that is the application you would want less weight for reduced gas consumption during acceleration.
Life has many variables don't always focus on 1.

[mikeyjd]

Also to have accurate mpg# you really need to do at least a half of a tank or more and best is to refill with the exact same pump you originally filled with. Another thing that can mess up numbers here is what size tires you are running? If you are not running a stock size tire then your odometer will be off so gps milage would be best used... lol sorry i have got pretty detailed on checking my mpg. my 88 carb with weber swap, stock motor and 185/60r14 tires and 4 adults in the car doing average of 75-80 mph got me average of 36 mpg which was really good. But if i would have been using my odometer for mileage i was showing like 32mpg which i knew was not correct thats when i used gps instead.

If you read what I wrote you will see that I noted that I was not claiming that the mileage was accurate, but rather using it as an indicator of possible gains from certain techniques. The techniques used in these tests did yield approximately the % increase that I was expecting based on other more thorough testing. My goal was merely to see how such techniques might help the Festiva

There is a mythbusters episode that they do a whole test on drafting a semi. The results were it does work but in order for it to work you have to be dangerously close to the back of the semi... for example look at nascar, when they are drafting they are within 1 foot or so of the car in front of them. I do think it would be easier to draft with a festiva because of the weight difference but i think you would have to still be pretty darn close and remember if you cant see the truckers mirrors... he cant see you, please be safe out there.

Yeah I've seen the episode. You can get noticable draft at 55mph at up to 80ft following a big rig.

Also on the freeway something you guys should know.
The more weight you have the better your car is at maintaining a certain speed.
The weight stores energy as forward motion and when approaching hills
while on the throttle it will lessen the rate which speed falls thus maintaining speed and using less gas in the average.
I used to do half tank fillups in Washington because I did so much freeway travel the weight used to help keep me moving forward.
And gave increased avg mpgs.
Not to mention the readout on the scanguageII giving accurate readings from the ecu.
So it is not that it is innaccurate its better with the weight on freeways I think most people don't think of this small fact.
It's almost the same purpose as a heavy flywheel and how it stores energy.

If you drive in the city a ton stop and go where you can't maintain velocity/momentum.
Then that is the application you would want less weight for reduced gas consumption during acceleration.
Life has many variables don't always focus on 1.

This is false. Added weight will have a negative effect on both highway and city driving, although it will be a much more noticeable effect in city driving. Do you have any links or sources for this information? The added weight does not work like a flywheel in any way. You might be able to achieve longer coasts but the end result of the acceleration portion will always be more fuel burned with more weight.

[Movin]

If you read what I wrote you will see that I noted that I was not claiming that the mileage was accurate, but rather using it as an indicator of possible gains from certain techniques. The techniques used in these tests did yield approximately the % increase that I was expecting based on other more thorough testing. My goal was merely to see how such techniques might help the Festiva



Yeah I've seen the episode. You can get noticable draft at 55mph at up to 80ft following a big rig.



This is false. Added weight will have a negative effect on both highway and city driving, although it will be a much more noticeable effect in city driving. Do you have any links or sources for this information? The added weight does not work like a flywheel in any way. You might be able to achieve longer coasts but the end result of the acceleration portion will always be more fuel burned with more weight.

Everything you said Mikey I agree with. In the above case fewer fill ups without the associated stop and go to get to and from may be the real reason some get better mileage starting with a full tank.

cars that never leave town and always do stop and go will benefit with the lighter tank.

[rmoltis]

Hey my cone filter reduced cylinder filling by up to %7
That oughtta save me some gass less air less fuel...

Yes my links and source are direct real time feedback direct from the ecu.
Ignition timing, engine load, mpg, rpms mph, mpg avg, coolant temp, intake air temp, throttle positin and real driving like you are doing. I can write my info down and link to it like everyone else does.

I only go off of my real time data not guessing what may and may not work.
My numbers are better proof than guesses.

And its not coasting its doing what your advocating.
I agreed with your results and now your saying the same principles are wrong.
I get up to speed and stay there and when there is a hill and your engine load increases you slowly
Ease off up the hill to keep mpgs high. This is where your extra weight bring you further up the hill while shedding less speed.

Plus yes that's only for the acceleration portion. But on the highway you accelerate once then maintain speed that's why it helps to have some weight to maintain speed and rpms even if its 1500 rpms.