thought on a way to increase fuel mileage. .just a thought

[RonD]

Yes, hydraulic drive for wheels/axles has been being tested for 20 years if not more, there are a few problems in "real world" daily driver applications.
And they still need a mobile power source, i.e. an internal combustion engine or battery.
With a battery a conversion to hydraulic wouldn't make sense, electric motor drive would be more efficient.
Internal combustion power converted to hydraulic would mean you could run engine at it's most efficient RPM to maintain hydraulic pressure and even shut engine off when pressure is high enough.
The numbers I have seen were 5,000psi in the pressure tank to do a hydraulic drive, and at high temperature for best performance, so waste heat from the engine could be used to heat the hydraulic fluid, hotter the better for more pressure, that is a plus.
But in the real world a 5,000psi pressure tank with very hot fluid inside would be quite a hazard even in a small fender bender with all 4 wheels having a high pressure hose that could be broken.
Be a hard sell to the general public IMO, and not sure it would be a lot more efficient if it has the same performance as a direct drive internal combustion engine car.
If it was slow and sluggish it would get much better mileage, but so would a direct drive, lol.



My lean towards thermoelectric energy recovery is because we already have the heat and are getting rid of it, so wasted energy.
Internal combustion engines need to operate in a specific temperature range to be efficient, below or above that temperature means wasted money.
We now throw a minimum of 60% of our fuel energy out to heat the air.
Remember Dad saying "Close the God Damn door I am NOT paying to heat the whole damn neighborhood!", lol.
Well that is what we are doing each time we drive.
If you pay $4/gallon for fuel, $2.40 of that is "to heat the whole damn neighborhood!"
And not even a thank you

So any heat we can recover in the form of useable electric power is a plus, even if it's only 10% that's $.40/gallon in your pocket.

 

[notaprob]

I drove around 85 mph for 300 miles going to my dads and gunning it every chance I had. I got 16.6 mpg. On the way home I decided to see how good of gas mileage I could get and I cruised about 65-70 mph and I was impressed how much difference it made. I got 23.3 mpg just for keeping my foot off of the floor.

 

[RonD]

Yes, making a more fuel efficient engine is a reality.
Making a more fuel efficient driver is probably not, remember the 55 MPH maximum speed limit, put in place to save fuel during "the energy crisis".

Where did it go?
The max. speed limit I mean, "the energy crisis" is still here , $4 a gallon!!!
LOL

 

[Hahnsb2]

okay so i'm not a wiz with gas engines (my degree is with diesels) but from my understanding the more vacuum a engine has the more efficient its running right? so my idea is instead of using engine vacuum to operate the brake booster and heater box blend doors have a remote electric vacuum pump for it. like on a diesel powered vehicle. now i do not know how much it would help if any which is why i'm asking, I've been wanting to put a vacuum gauge on my ranger and get some base measurements and then try my thought.

whats everyone's thoughts on it?

No.

Powering vacuum accessories doesn't require any power from the engine. The vacuum is already there and they're just tapping into it. You will not see a change in manifold vacuum by eliminating these items.


Now if you run an electric vacuum pump, your alternator will have to run this, and this will use power from your engine, but likely wouldn't be noticeable.


Engines can actually get better gas mileage by being leaned out, there is less power when running lean, so the throttle is opened more to maintain the same speed, reducing the vacuum which in turn reduces pumping losses.

 

[1996DANGERRANGER]

but back to my statement of the more vacuum the better efficiency. i worded that poorly, but if you have more vacuum the more possible air that is going into the cylinders and being compressed(assuming that your rings and valves/seats are good) and when you put your foot on the brake the valve on your brake booster open which increases the area for vacuum and decreasing it. kinda like putting the wide head on your shop vac. does suck up as much. so if you could eliminate that with a small electric vacuum pump then your engines vacuum would only change with rpm change and shifts

 

[RonD]

Eliminating the vacuum on gas engines would be best, no throttle plate(this creates the vacuum) or "manifold", use direct injection like a diesel engine.
GDI is it's current name, but it has been around as long as gas engines, bottomline is that it is less complicated to use a throttle plate and fuel injectors in a manifold vs in the cylinder.

But GDI is more fuel efficient.

A power brake booster works a little different than you described.
Between the master cylinder and the firewall is the vacuum chamber, in it is a diaphragm, on the master cylinder side of the diaphragm is the low pressure(vacuum) on the other side of the diaphragm is what becomes the "high pressure" side but only when brake pedal is pushed.

When brake pedal is pushed a seal around the rod that runs to the master cylinder is opened and the 15psi of normal atmospheric pressure is allow to enter the "high pressure" side of the diaphragm, because of the lower pressure on the vacuum side you get an "assist" from the higher pressure side in pushing on the pedal.

On the power booster vacuum line is a check valve, this is a safety feature that allows power braking even if engine has shut off.
When engine is idling, throttle plate closed, the power booster is fully "charged" with it's lowest pressure, the check valve prevents loss of this low pressure even with engine at full throttle, least vacuum pressure.
So when you use power brakes you are using the vacuum from the last time you were idling, or throttle plate was closed.
There is no cost in "charging" the power booster with low pressure since that is free during idling, it draws no power and is a closed system.
So when you press down on the brake pedal no "extra" vacuum is use, and the vacuum area gets smaller not larger.

Now the thinking on vacuum assisted power brakes is that you usually only use the brakes if your foot is off the gas pedal, so throttle plate is closed and highest vacuum is available.

There were vacuum power windshield wipers at one time, lol, yes there were.
But there was a problem, if it happened to be raining and you were driving uphill at speed for any length of time, the vacuum was reduced to the point that the wipers were at best ineffective.


Vacuum power is free if there is a throttle plate, getting rid of the throttle plate would be where you would save on fuel.

 

[1996DANGERRANGER]

so what would need to be done to the engine to eliminate the throttle plate and run properly?