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-   -   Saving gas by not changing lanes? (https://www.fuelly.com/forums/f33/saving-gas-by-not-changing-lanes-9656.html)

LoudAccord 08-06-2008 10:35 AM

Saving gas by not changing lanes?
 
I figure that when you turn, you have to use your power steering pump which means more draw on the pully. I gave this a try and got 2mpg better by not changing lanes. Any input?

justa4door 08-06-2008 10:41 AM

Quote:

Originally Posted by LoudAccord (Post 114183)
I figure that when you turn, you have to use your power steering pump which means more draw on the pully. I gave this a try and got 2mpg better by not changing lanes. Any input?


i think next time dont even turn :gotme: or cut the PS belt and put water in your oil it will cool faster thus makeing the car run better

dkjones96 08-06-2008 10:48 AM

Hmm. I wouldn't think that changing lanes would cause that much of a load from the power steering pump. Most cars and even large trucks can change lanes without much effort without power steering.

Too bad you have an 06(serpentine belt). Anyone with an older car tried removing the belt for the PS pump completely? It sucks but might be a good place to look for gains.

What about having a hydraulic(or pneumatic) pressure storage tank and having the pump charge the tank on decel? Then you could have power steering without the constant load? That won't work. Power steering systems run an open loop that flows constantly and freely when no turning is done and loads the pump by restricting the exit to one side of the rack to create pressure and the assist.

Sorry, thinking out loud.

justa4door 08-06-2008 10:57 AM

Quote:

Originally Posted by dkjones96 (Post 114186)
snip

What about having a hydraulic(or pneumatic) pressure storage tank and having the pump charge the tank on decel? Then you could have power steering without the constant load? That won't work. Power steering systems run an open loop that flows constantly and freely when no turning is done and loads the pump by restricting the exit to one side of the rack to create pressure and the assist.

Sorry, thinking out loud.

why spend more money then you will ever save on building that

dkjones96 08-06-2008 11:10 AM

Quote:

Originally Posted by justa4door (Post 114188)
why spend more money then you will ever save on building that

Yeah, after posting that I thought of how cheap and easy it would be to just have a micro-switch on the throttle to activate or deactivate an electromagnetic clutch for the thing.

gridefosho 08-06-2008 11:11 AM

It's to my understanding that if you are to blow a load in the pump it lubricates better resulting in less power needed.

justa4door 08-06-2008 11:23 AM

Quote:

Originally Posted by gridefosho (Post 114196)
It's to my understanding that if you are to blow a load in the pump it lubricates better resulting in less power needed.

would need at least 3 or 4 friends to help with this .. but may work I will try

aalb1 08-06-2008 11:24 AM

Describe your drive a little more... As of now I'm thinking that the 2mpg is more a result of other things rather than less PS use. Aren't you surprised that you gained 2mpg from less PS use?

I'm thinking this.... Changing lanes means you need to pass someone. Passing usually results in faster speeds and more acceleration periods. Staying in one lane means that you'll stick to a fairly constant speed, and usually a slower speed and in return less aero drag.

See what I'm getting at?

bobc455 08-06-2008 11:24 AM

Actually turning a car takes almost no energy whatsoever.

If you ever get a car on a single-post center lift (like the next time you get a set of new tires), you will notice that you can rotate a car with your pinky finger.

At highway speeds you could remove the belt from your P/S pump, and you wouldn't feel any different. (Please, nobody try to remove their belt while driving at highway speeds!) The only time you need P/S is in parking lots.

Even if you take a hard corner, there is really no energy required to do that- the only energy required is to change the rotational inertia of the vehicle. Once you have started to take a corner, no further energy input is required. (To visualize this, think about a zig-zagging car instead of a car doing a single circle. The zig-zagging car will lose its momentum faster, since you are rapidly accelerating the rotation in opposite directions.)

Holding a car in a circle does load up the suspension, but those are static loads and do not require energy "input" once the car has started to rotate.

-Bob C.

justa4door 08-06-2008 11:29 AM

Quote:

Originally Posted by bobc455 (Post 114201)
Actually turning a car takes almost no energy whatsoever.

If you ever get a car on a single-post center lift (like the next time you get a set of new tires), you will notice that you can rotate a car with your pinky finger.

At highway speeds you could remove the belt from your P/S pump, and you wouldn't feel any different. (Please, nobody try to remove their belt while driving at highway speeds!) The only time you need P/S is in parking lots.

Even if you take a hard corner, there is really no energy required to do that- the only energy required is to change the rotational inertia of the vehicle. Once you have started to take a corner, no further energy input is required. (To visualize this, think about a zig-zagging car instead of a car doing a single circle. The zig-zagging car will lose its momentum faster, since you are rapidly accelerating the rotation in opposite directions.)

Holding a car in a circle does load up the suspension, but those are static loads and do not require energy "input" once the car has started to rotate.

-Bob C.

most hondas came w/o PS .this is one thing most people dont know and wonder why hondas get 10+ mpg more.. and really its not that bad in a parking lot.. you get used to it really fast..IE like haveing to roll a lil before you start to turn

VetteOwner 08-06-2008 12:44 PM

Quote:

Originally Posted by bobc455 (Post 114201)
Actually turning a car takes almost no energy whatsoever.

If you ever get a car on a single-post center lift (like the next time you get a set of new tires), you will notice that you can rotate a car with your pinky finger.

At highway speeds you could remove the belt from your P/S pump, and you wouldn't feel any different. (Please, nobody try to remove their belt while driving at highway speeds!) The only time you need P/S is in parking lots.

Even if you take a hard corner, there is really no energy required to do that- the only energy required is to change the rotational inertia of the vehicle. Once you have started to take a corner, no further energy input is required. (To visualize this, think about a zig-zagging car instead of a car doing a single circle. The zig-zagging car will lose its momentum faster, since you are rapidly accelerating the rotation in opposite directions.)

Holding a car in a circle does load up the suspension, but those are static loads and do not require energy "input" once the car has started to rotate.

-Bob C.

yup, to prove this, start your car and leave it in park, turn the wheel and listen to the power steering pump while while you turn, then leave the wheels turned, it doesnt strain anymore! cuz its not needing any hydrolic input from the pump so it will use virtually no energy. (kind like with a riding mower/gokart/atv. once the wheels are turned it doesnt take any effort to keep them turned. even while changeling lanes, next time SAFELY glance at the wheel and actually look how far you turn he wheel, your only rotating it maybe 1-2 degrees from normal and usually you turn the wheel, wait for the car to change then turn back.

if your gaining 2mpg by not changeling lanes u need to get the grease out of your power steering:D (PSF is like water, some use brake fluid, also like water)

if you ever have your serpentine belt off (any of you) give the pump a spin by hand, youd be surprised how little resistance it has.

yes u only need power steering in parking lots and even then not really.

Jay2TheRescue 08-06-2008 12:54 PM

Quote:

Originally Posted by bobc455 (Post 114201)
Actually turning a car takes almost no energy whatsoever.

If you ever get a car on a single-post center lift (like the next time you get a set of new tires), you will notice that you can rotate a car with your pinky finger.

At highway speeds you could remove the belt from your P/S pump, and you wouldn't feel any different. (Please, nobody try to remove their belt while driving at highway speeds!) The only time you need P/S is in parking lots.

Even if you take a hard corner, there is really no energy required to do that- the only energy required is to change the rotational inertia of the vehicle. Once you have started to take a corner, no further energy input is required. (To visualize this, think about a zig-zagging car instead of a car doing a single circle. The zig-zagging car will lose its momentum faster, since you are rapidly accelerating the rotation in opposite directions.)

Holding a car in a circle does load up the suspension, but those are static loads and do not require energy "input" once the car has started to rotate.

-Bob C.

Even with a relatively light car power steering is noticeable. My Buick which only weighs 3,283 lbs was a beast to drive when the power steering pump went out years ago. I would not recommend disconnecting the power steering pump and this is my reasoning behind it:

1. The steering box was designed with power steering in mind. A car with inoperative power steering is harder to drive than a similar vehicle that was not equipped with power steering.

2. The steering box, and/or rack & pinion on FWD cars was designed to use the flow of power steering fluid from the pump for lubrication. Disconnecting the pump could mean costly steering component repairs later - probably more than whatever gas you saved.

If you are considering cutting out the power steering get the related components from a non-ps car and convert the vehicle so that it is setup as the non power steering models were.

-Jay

EDIT: I was just thinking... Many vehicles (Including my pickup truck) now have speed sensitive power steering. At highway speeds the system cuts the boost anyway...

ffvben 08-06-2008 03:09 PM

some cars don't use their power steering above a certain speed/or turn radius. its mainly for slow/parking lot maneuvers that it assists the driver.

theholycow 08-06-2008 03:16 PM

Holy crap, this thread is a mess!

Quote:

Originally Posted by Jay2TheRescue (Post 114229)
EDIT: I was just thinking... Many vehicles (Including my pickup truck) now have speed sensitive power steering. At highway speeds the system cuts the boost anyway...

Thank you for using facts and sense.

My 3000 pound VW's electric power steering is pretty much off at speeds greater than maybe 20mph.

Power steering just does not take much energy. Even if power steering used a lot of engine power to turn, consider just how much you turn the steering wheel to change lanes. It's tiny, barely different from the normal adjustments you use to keep your car straight in its lane.

GasSavers_theCase 08-06-2008 03:33 PM

Rotational interia!
 
A very minor (miniscule) bit of energy loss can be attributed to overcoming the rotational inertia of the wheels and tires when changing lanes., i.e., it would take some energy to change the plane of rotation (four wheels/tires weighing 30 lbs each at 600 rpm...).

Just thought I'd muddy the waters a bit.

Jay2TheRescue 08-06-2008 03:52 PM

Quote:

Originally Posted by theCase (Post 114257)
A very minor (miniscule) bit of energy loss can be attributed to overcoming the rotational inertia of the wheels and tires when changing lanes., i.e., it would take some energy to change the plane of rotation (four wheels/tires weighing 30 lbs each at 600 rpm...).

Just thought I'd muddy the waters a bit.

Full time PS is nice though... I can steer my Buick with my pinky finger... It really wasn't built with mileage in mind though, comfort was their primary concern. I didn't notice how much I had gotten used to the speed sensitive PS until I had gotten Rusty back on the road. The first time I drove Rusty after we got him back on the road it was difficult for me to keep it on the road. It took me a few miles to get used to it again.

-Jay

VetteOwner 08-06-2008 04:13 PM

Quote:

Originally Posted by Jay2TheRescue (Post 114262)
Full time PS is nice though... I can steer my Buick with my pinky finger... It really wasn't built with mileage in mind though, comfort was their primary concern. I didn't notice how much I had gotten used to the speed sensitive PS until I had gotten Rusty back on the road. The first time I drove Rusty after we got him back on the road it was difficult for me to keep it on the road. It took me a few miles to get used to it again.

-Jay

yea alot of the older cars had way over powered PS pumps. i remember my friends 1975 mavericks steering was so light you could sneeze on it and it would turn.

i much rather have little help/no power steering. chevette has none and the s-10's is going out (stillt here btu takes some effort to move) i like to feel like im accually driving, like the steering wheels accually connected to the car lol

theholycow 08-06-2008 04:35 PM

I like effort so light that I can steer by just giving the steering wheel a dirty look.

Jay2TheRescue 08-06-2008 04:50 PM

Quote:

Originally Posted by VetteOwner (Post 114268)
yea alot of the older cars had way over powered PS pumps. i remember my friends 1975 mavericks steering was so light you could sneeze on it and it would turn.

i much rather have little help/no power steering. chevette has none and the s-10's is going out (stillt here btu takes some effort to move) i like to feel like im accually driving, like the steering wheels accually connected to the car lol

Rusty's PS pump is going out. The pump makes a knocking sound at idle. Dad & I kept going over it and when we determined it was the PS pump we just decided to just drive it till the pump either siezed up or started leaking. We only put it back on the road to make trips to the landfill and the hardware store. We plan to drive it under 1,000 miles/yr so it could go quite some time like this. The Buick is so good that you can put it in the slightest rut of the road, and it would actually follow corners on the highway without touching the wheel. A friend of mine has a 1970 Buick Riviera and that car's power steering is like a hot knife through butter.

-Jay

GasSavers_JoeBob 08-06-2008 05:40 PM

Quote:

Originally Posted by dkjones96 (Post 114186)
Hmm. I wouldn't think that changing lanes would cause that much of a load from the power steering pump. Most cars and even large trucks can change lanes without much effort without power steering.

Too bad you have an 06(serpentine belt). Anyone with an older car tried removing the belt for the PS pump completely? It sucks but might be a good place to look for gains.



Sorry, thinking out loud.

Actually, I have. A 1962 Rambler. The power steering pump died, so I just removed the belt. The car was light enough that even my wife didn't miss the power steering. However, I never noticed any difference in FE.

Jay2TheRescue 08-06-2008 05:59 PM

Quote:

Originally Posted by theholycow (Post 114274)
I like effort so light that I can steer by just giving the steering wheel a dirty look.

I imagine your LeSabre meets and/or exceeds those expectations... I remember my old Bonneville wagon was a sheer pleasure to drive on the highway. I'd set the seats and the cruise, then pull the tilt wheel all the way down. I'd have the steering wheel in my lap, and steer with 2 fingers. I do the same with all my vehicles. The only one that isn't as compliant is the Beast as it has speed sensitive power steering so you really need a little more than 2 fingers to drive. Usually its 2 fingers & a thumb. My mom used to have a Taurus and I absolutely hated it because you could not drive it on the highway with just a few fingers. I only made one road trip in that car. I just couldn't stand it.

-Jay

VetteOwner 08-06-2008 06:23 PM

Quote:

Originally Posted by Jay2TheRescue (Post 114280)
I imagine your LeSabre meets and/or exceeds those expectations... I remember my old Bonneville wagon was a sheer pleasure to drive on the highway. I'd set the seats and the cruise, then pull the tilt wheel all the way down. I'd have the steering wheel in my lap, and steer with 2 fingers. I do the same with all my vehicles. The only one that isn't as compliant is the Beast as it has speed sensitive power steering so you really need a little more than 2 fingers to drive. Usually its 2 fingers & a thumb. My mom used to have a Taurus and I absolutely hated it because you could not drive it on the highway with just a few fingers. I only made one road trip in that car. I just couldn't stand it.

-Jay

What year? our 97 is kinda annoyign to drive too, it liek gets hard even tho your just chaneging lanes. now our 96 aerostar my gawd! if your on a bumpy road the van is hard to control cuz the steerings so light, your arms bouncing turns the wheel, makes one handed steerign near impossible

Jay2TheRescue 08-06-2008 06:39 PM

Quote:

Originally Posted by VetteOwner (Post 114283)
What year? our 97 is kinda annoyign to drive too, it liek gets hard even tho your just chaneging lanes. now our 96 aerostar my gawd! if your on a bumpy road the van is hard to control cuz the steerings so light, your arms bouncing turns the wheel, makes one handed steerign near impossible

Holy Cow has a 1980 Buick LeSabre. Your 97 LeSabre should have speed sensitive power steering. I can feel when it steps down in my truck, its about 30 MPH.

-Jay

VetteOwner 08-06-2008 06:58 PM

it could, its a 97 with some 98 parts (tail end of the 97 model year) makes fixing it a PITA....

wish my car and truck had tilt steering wheels... (i can put one in the s-10 but ive gotten used to where it is, chevette was an option but a rare option...)

Jay2TheRescue 08-06-2008 07:14 PM

Quote:

Originally Posted by VetteOwner (Post 114289)
it could, its a 97 with some 98 parts (tail end of the 97 model year) makes fixing it a PITA....

wish my car and truck had tilt steering wheels... (i can put one in the s-10 but ive gotten used to where it is, chevette was an option but a rare option...)

The only vehicle I have ever owned that didn't have a Tilt wheel was my 74 Chevy pickup. Everything else has Tilt. Your LeSabre should have had Tilt standard...

-Jay

justa4door 08-07-2008 03:29 AM

i cut my belt yesterday .... the only problem i had was today my BATT. light started to flash and my radio died..and my heat would not heat up.... i dont know i got to work and parked it so we will see what happens on my drive home

theholycow 08-07-2008 05:04 AM

It sounds like you cut the alternator belt, not the power steering belt...

Jay2TheRescue 08-07-2008 05:17 AM

Quote:

Originally Posted by theholycow (Post 114343)
It sounds like you cut the alternator belt, not the power steering belt...

Could it be on that particular vehicle the PS belt also goes around the alternator?

KU40 08-07-2008 05:28 AM

Quote:

Originally Posted by VetteOwner (Post 114267)
yes they will spring back on sharp curves i was talking about changeing lanes, and in parking lots where your not moving the whole point is the power steering helps you turn the wheel once its turned it isnt needed much (some from varying the wheel a tad)

it springs back to straight from the way the suspention/alignment /tires. hence why if its in alignment you can generally set the car straight and let go of the wheel and it should stay straight for quite a distance. its designed to do that.

Isn't this also because the rear wheels are wanting to go straight?

GasSavers_landon 08-07-2008 06:13 AM

Quote:

Originally Posted by KU40 (Post 114358)
Isn't this also because the rear wheels are wanting to go straight?

No, inanimate objects don't "want" to do anything. They just obey the laws of physics. It really has most to do with the amount of caster in your front suspension.

KU40 08-07-2008 09:04 AM

Quote:

Originally Posted by landon (Post 114370)
No, inanimate objects don't "want" to do anything. They just obey the laws of physics. It really has most to do with the amount of caster in your front suspension.

Physics is what I'm talking about. Due to inertia your car always wants to go straight once it is moving in a certain direction. The front wheels turning changes what it physically does, but with every snapshot during your turn, your car wants to go straight because of its forward momentum. Rotational movement is just the sum of all the infinite straight lines that tangent out from that circle. With things like a ball on a string that you twirl around, the string holds it to the pivot point- your hand. Without that connection (e.g. let go of the string), what does the ball do? Shoot straight out in the direction of one of those infinite tangent lines at that instant. It doesn't keep going in the circle. However, your car has no string holding it to the center pivot of the corner you're taking. So it wants to fly straight off every instant at the corresponding tangent. But the tires gripping the ground and the turning of the front wheels overcome that force.

I'm not saying the front end isn't part of it though.

VetteOwner 08-07-2008 01:57 PM

Quote:

Originally Posted by justa4door (Post 114327)
i cut my belt yesterday .... the only problem i had was today my BATT. light started to flash and my radio died..and my heat would not heat up.... i dont know i got to work and parked it so we will see what happens on my drive home

umm... if your heat isnt heating up then that means you cut the belt to the water pump too, have fun dealing with a cracked head when it over heats:p that is if it even starts up...(if theres not enough juice to run a radio then theres not gonna be enough to start the thing)

Lug_Nut 08-08-2008 12:13 PM

Power steering uses LESS energy while turning the steering wheel. Holding the wheel in one position uses MORE energy.

The pump contains a relief valve. The pressure builds up until this relief setting and then the fluid pressure bleed off the excess above this setting. During the act of spinning the steering wheel some of this internal pressure is diverted to one side of the steering unit and trapped fluid on the other is allowed back to the reservoir. This diversion of pressure reduces the load on the pump until the steering wheel stops turning, no more fluid is added to one side nor drained from the other and the pump pressure rises again.
The faster the steering wheel can be twiddled from left to right, the more volume is needed from the pump to keep up with the flow rate and the lower the pressure drops. Spin the wheel from lock to lock quickly enough with the engine at idle and the volume change in the rack or recirculating ball assembly can be more than the pump's volumetric output at that engine rpm, no pressure for assist, but maximum flow rate (at that rpm) through the system.
A basic law of hydraulics (and pneumatics) is that pressure is resistance to flow. No flow conditions produce the maximum pressure. Holding the wheel in one position (driving straight or a constant turn) makes the pump work harder. That in turn puts more load on the belt driving it and the engine driving the belt.
Fuel savings? Find the relief valve setting on the pump and relax it. You'll need a bit more armstrong at parking speeds, but the reduction of wasted overpressurization at all other times will result in a fuel savings.


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