Fuel saving on manual car?

Question

hi there, im driving manual car. Need to know if this works:

1) a friend of mine told me if putting Free-gear while going downhill will save fuel.

2) constanly change to free gear whenever we have chance to do so even in flat road.

3) will constanly changing to free-gear in various speed will effect the car in long term?

thanks. let share this together.

Answer 1

Well, "Lover Not A Fighter" got it mostly right, although I can't figure how coasting in neutral would "kill the tranny."

The bigger mistake is that you DO NOT use less gas coasting in neutral than you would simply letting up on the throttle all the way.  The reason is that even coasting in neutral your engine is idling, which means it is using some gas.  But when you close the throttle completely in gear, your engine computer shuts off all fuel to the engine, to reduce pollution emissions.  Every foot you go with yours off the throttle is fuel-free.

Other ways to save fuel:

-- Use full synthetic oil in the lightest weight recommended by the manufacturer and change the filter at every oil change.

-- Keep your tires inflated to the pressure recommended on the plate on the driver's side door frame.  DO NOT inflate to the maximum pressure shown on the tire sidewall.  Your tires are part of the suspension system, and overinflation causes premature shock absorber wear.  Overinflation also causes the tires to wear in the middle, and reduces the contact patch, adversely affecting handling.

-- Learn to short-shift (get into higher gear as quickly as practical), or fool your automatic transmission into shifting early.  It takes a feel for letting up on the throttle slightly just before it would normally shift, or speeding up slightly faster than you need to go so that it upshifts, then backing off easy, so that it does not downshift again.  This keeps your throttle wider open on the average, which reduces intake restriction.

-- Take all the c**p out of your trunk.  Extra weight = lower mileage.

-- Take that roof rack off.

-- Keep your windows rolled up.

-- Keep as much speed through corners and curves as is safe.  This goes along with LNAF's admonition to keep a steady speed.

Answer 2

not a good idea you need gears to slow down, to save on your brakes

Answer 3

If you mean neutral, then yes, coasting lets the engine idle and an idling engine uses very little fuel. It will do no damage but you might accelerate brake wear if your not using engine drag to slow the car.  Not a big deal at $4/gal.

Answer 4

with a manual transmission, you can coast.

in fact, if you're REALLY OLD, maybe you remember folks shutting their car off going down long hills.

down at the bottom, you pop the clutch and restart.

not such a good idea today, what with power steering and brakes.

in some states, you're not supposed to coast.

i mean, we wouldn't want to not be using gas, now would we.

sometimes, when there are stretches that are slightly down hill, you can coast, and every once in a while, pick up speed again.

Answer 5

>> 3) will constanly changing to free-gear in various speed will effect the car in long term?

That is like getting the car towed.  And it will kill the tranny.

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Coasting down hill saves gas.  But coasting and by accelerating and then coasting, etc. uses MORE gas.  It saves more gas to just cruise.  Here are real way to save gas.

There are few thing you can do to save (or maximize) gas MPG. First get a tune-up.

(1) spark plugs

(2) spark plug wires

(3) distributors, coil, rotors (if you have them).

(4) new air filter

(5) PCV

(6) correct tire pressure

(7) clear the trunk of useless heavy items

(8) spray clean MAF sensor.

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Forget all those "SAVE GAS" scams.  This was on NBC morning TV show.   The difference is as much as 38% (their claim).  There are very simple rules to save gas:

(1) drive slow - not too much past 55

(2) accelerate slowly

(3) don't brake unnecessarily

(4) use cruise control - whenever it is safe to do so.

Don't coast - it is NOT safe (to coast in Nuetral) and it does NOT save gas.  It only saves gas, if you are planning to slow down (exiting, tolls, traffic).  Coasting then accelerating again is LESS efficient than just cruising.

The above really works. Using those simple rules I was able to drive from Boston to NYC (210.5 miles) on just 5.112 gallon (94 Civic).  That's 41 MPG (94 Civic 187K miles).  Actually I was speeding at 72 MPH so I could do even better at 55.

WOW !!

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SUMMARY :  using constant engine LOAD is the best way to save gas.  But using the cruise is the second best way (and the easiest)

Good Luck...