Getting outrageous milage!!!!

[alpurl]

I've also just read Goose's post in the Saving gas in neutral thread on page three.

There he thoroughly explained the logic behind his argument.

I therefore must sadly state the following three words.

It makes sense.

Since this was posted in a completely different thread, I've taken the liberty of pasting his entire post below.

Also, here is the link for his post there directly, so you can see the context of his post.
http://www.automotiveforums.com/vbul...6&postcount=44

Originally Posted by Greygoose

ok, i dont know how this got so confused but here are the basics...
(all statments assume that you are using the same engine, and unless stated, are using it under the same conditions)

running an engine uses fuel
running an engine at a certain rpm uses a certain ammount of fuel
running an engine at a lower rpm uses less fuel and produces less power
to compensate for producing less power at a lower rpm, more throttle must be applied
when an engine produces the same power at a lower rpm it is running more efficiently
when an engine is running more efficiently it uses less gas.


the reason engines run more efficiently at lower rpms with more throttle is that there is less drag on the engine.
the major source of drag on an engine is the throttle plate. when it is closed there is so much drag on an engine that it produces verry little power and does it very in-efficiently.

think of a washing machine. when you want to wash your clothes, you save up until you have enough to fill the washing machine befor washing your clothes. you wouldnt run a wash if all you wanted was to wash a single pair of socks. it would be hugely in-efficient. an engine works the same way. it all has to do with loading. an engine gets its best mileage under a high load, at a low rpm, under full throttle.

this is why high horsepower engines use more gas. it is like having a washing machine running to wash a pair of socks.

while it is true that you cannot easily compare different types of engines, you can compare them to figure out why smaller engines get better gas mileage. consider the engine from a dodge viper. it makes 500 hp, and has 10 cylinders. now consider an old honda engine. they typically made 80 hp and had 4 cylinders. lets say it takes only 30 hp to drive 70 mph. in the viper, you are going to be driving at maybe 10% throttle. in the honda, you are going to be using something more like 85% throttle. the honda will get better mileage because the engine is sized more accuratley to the load required of it. why move 10 cylinders, when 2 is all thats required. why run a wash to wash a single pair of socks when you could save up until you could fill the washing machine and use it more efficiently.

[alpurl]

I just thought of something.

Though I didn't quite grasp the drag via throttle thing initially, I think that's part of what I was alluding to in earlier posts regarding using a slightly higher gear ratio in the final drive to allow the engine to rev at a slightly higher rpm, but using less fuel to overcome the load of using the lower gear ratio.

[GreyGoose006]

the main killer of gas mileage is rpm's. the higher you rev, the more friction there is, the stronger the pumping losses are, and the more energy is wasted in the form of heat, and vibration.

i can post the pic, but it can be found eslewhere on AF.

[GreyGoose006]

since i'm too lazy to find it, here ya go

[KiwiBacon]

Originally Posted by alpurl

I just thought of something.

Though I didn't quite grasp the drag via throttle thing initially, I think that's part of what I was alluding to in earlier posts regarding using a slightly higher gear ratio in the final drive to allow the engine to rev at a slightly higher rpm, but using less fuel to overcome the load of using the lower gear ratio.

You're contradicting yourself.

Higher gear ratios = lower engine revs. Which do save fuel through less work against friction and making the engine run with a more open throttle.

Gearing an engine down to reduce load and save fuel doesn't work.

[Schister66]

its a little OT, but since i turboed my GSR i saw a jump in mileage...

In town was 25-27, now it is about 26 (22 when i get on it)

Highway was 30-32, now it is 32-36mpg

By no means did i boost it for the mileage, but hell, it doesn't hurt

[KiwiBacon]

Originally Posted by Schister66

its a little OT, but since i turboed my GSR i saw a jump in mileage...

In town was 25-27, now it is about 26 (22 when i get on it)

Highway was 30-32, now it is 32-36mpg

By no means did i boost it for the mileage, but hell, it doesn't hurt

Is it boosting at cruise?

A mate of mine bolted a larger turbo to his Mazda MX6, taking the boost range to above cruising speed. His fuel economy improved noticably.

[Schister66]

Originally Posted by KiwiBacon

Is it boosting at cruise?

A mate of mine bolted a larger turbo to his Mazda MX6, taking the boost range to above cruising speed. His fuel economy improved noticably.

my crusing speed is about 4000rpm on my GSR and full boost on my turbo is 4500-4600rpm depending on the gear so i dont think i'm getting boost per say, but i'm getting the benefits from the extra air moving through

[turtlecrxsi]

Schister, you are cruising in boost. That is pretty cool because you have power without downshifting. My wife's 1.8t VW passat is boosted but it really doesn't run smoothly and efficiently (ie. having to gas it to get it going... 2nd gear in 5 speed auto is worthless) unless cruising over 60mph. Full boost is at 3k rpms. The car only operates at this engine speed continuously in the highest gear at say 70-75mph hence making the most torque and having my foot back off the accelerator...

[GreyGoose006]

just a thought, but what if you purpose built a turbo to improve gas mileage.
are there any turbo designs that make lots of boost at cruisin rpms, w/o causing too much back pressure? i know that the smaller your turbo is, the lower rpms it makes boost at. what about on a V8-I6 with small diameter headers to get the exhaust moving fast, and a fery efficient turbo design that was engineered to make 75% boost at around 2500 rpm. maybe just a dream, but maybe not... anyone know anything

[KiwiBacon]

Originally Posted by GreyGoose006

just a thought, but what if you purpose built a turbo to improve gas mileage.
are there any turbo designs that make lots of boost at cruisin rpms, w/o causing too much back pressure? i know that the smaller your turbo is, the lower rpms it makes boost at. what about on a V8-I6 with small diameter headers to get the exhaust moving fast, and a fery efficient turbo design that was engineered to make 75% boost at around 2500 rpm. maybe just a dream, but maybe not... anyone know anything

For a turbo to be needed at cruise, you'd be looking for a very small engine.
Something like the smart cars.

[MiggityMike]

I am getting 110-130 mpg depending driving conditions. I first got my 4 popper 2005 Canyon last summer and found it got worse gas mileage than a 1984 4 cylinder S-10. So I made a part to crack gas and get sweet mileage.

[MiggityMike]

Originally Posted by GreyGoose006
just a thought, but what if you purpose built a turbo to improve gas mileage.
are there any turbo designs that make lots of boost at cruisin rpms, w/o causing too much back pressure? i know that the smaller your turbo is, the lower rpms it makes boost at. what about on a V8-I6 with small diameter headers to get the exhaust moving fast, and a fery efficient turbo design that was engineered to make 75% boost at around 2500 rpm. maybe just a dream, but maybe not... anyone know anything

Yes! it was on the cover of popular meachnic a few months ago it made 300 horsepower and ran on something like 1500 PSI.

Heres a generator that makes 20,000 watts free and runs by intself - http://www.lutec.com.au/index.htm
"The technology is currently performing at a robust 150% net gain, an overall efficiency of 250%, so the 100% net gain used in the above examples is more than achievable now, not after tweaking or adjusting or changing anything. It is available for testing and to go into production immediately."

I am not a total hippie, I just love not paying more when I don't have to. Especially when I can get from here, Indiana, to L.A. on one tank of gas...

[KiwiBacon]

Originally Posted by MiggityMike

Heres a generator that makes 20,000 watts free and runs by intself - http://www.lutec.com.au/index.htm
"The technology is currently performing at a robust 150% net gain, an overall efficiency of 250%, so the 100% net gain used in the above examples is more than achievable now, not after tweaking or adjusting or changing anything. It is available for testing and to go into production immediately."

I am not a total hippie, I just love not paying more when I don't have to. Especially when I can get from here, Indiana, to L.A. on one tank of gas...

Dude that didn't even run, let alone generate any power.

[GreyGoose006]

hmmm. interesting, BUT...
COMPETELY OFF TOPIC...

that is a generator. we are talking about engines. the latest discussion as about turbos.

about the generator however. there are laws of physics and science that, while not guranteed, have never been broken. it is not possible for a machine to be more than 100% efficient in the REAL WORLD. in fact, it is un likely that any machine will ever even approach 100% efficiency. most machines run at around 78-96% depending on how well they were engineered and constructed.

it is not possible to have a motor run only with permanent magnets. there must be something making it GO... unless you have just discovered perpetual motion, which is what this is nearly claiming to be.

sorry to be so long winded, but i have shown this link to many people and everyone agrees that it is IMPOSSIBLE...

thank you.
that is all.