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

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.


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