That's why I said it was counter-intuitive. Think about doing a rolling start and popping the clutch--it doesn't take any expended fuel to make the engine turn over. There are plenty of articles online if you'd like to read about it further. Here's a snippet from Wikipedia:

Here's a Popular Mechanics article about it. It's good info for any manual driver to know.

 

It is true that the engine mapping shuts off the fuel supply when the rpms are high enough and the throttle is released.

From page 39 of the attached document:

"As the throttle is closed, the EMS2000 decreases the injection ms value (fuel shut off) if the rpm is above idle speed (coasting). This feature decreases fuel consumption and lowers emissions. When the engine rpm approaches idle speed, the injection ms value is increased (cut-in) to prevent the engine from stalling.

So, option 3 is the best for gas mileage. My vote goes to option 3, and it is what I do most often.

 

I say use the breaks and the engines natural compression to slow the car, match the gear to the speed so that you retain control of the car(too many stupid people out there to be coasting), I don't really believe that you gain any significant saving in wear on the engine and the clutch in the process of coming to a stop... if you are really that concerned with wear and tear I'd look toward how you start from the stop and your method in going up through the gears.... but to each their own...

 

here is another thought on decel to stop ...

there are 3 ways to avoid an accident:

1)stop before it
2)manuever around it
3)accelerate through it

if you are coasting in neutral, you have only 2 of the 3 available to you

i always gearchange up or down to keep the car in an appropriate gear for the speed i am currently running

as for coming to a full stop, just as the rpm reduces to idle in 1st gear, i then declutch and shift to neutral and immediately let the clutch out

the exception to this is using #1 above ... if using the brakes to avoid an accident, ie "panic stop", clutch pedal to the floor and shift to an appropriate gear when able .... ie this may mean a 6th to 2nd shift

i was taught this in 1970 high school drivers ed, we drove chevy biscaynes with 327 engines, 2 barrel carbs and "3-on-the-tree" manual shifts, no power steering, no power brakes

in 1975, when i took my first track riding motorcycle lesson, we were again taught the 3 ways to avoid an accident and to always keep the transmission in gear, never coast in neutral

scott

 

I'll be damned. You thoroughly proved me wrong on that, chrunck! And I will happily admit that I just wouldn't have thought the injectors would completely turn off, even with the wheels driving the engine. Thanks for making me smarter! haha

 

this has been used in motor vehicles for many years, my 1987 bmw k75s motorcycle turns the injectors off when coasting in gear with the throttle closed ... at least it did until i put mikuni roller square slide smooth bore carbs on it


scott

 

Well, just call me old. I learned from my Dad to rev match and downshift through the gears when I first started driving in 1961. Maybe it was because of less efficient brakes in those days, but that was the proper way to drive safely. I have always felt downshifting gives more control over the car than coasting. I certainly would never coast to a stop in neutral. My first ride was a 1960 Simca (POC) with four on the column. I then graduated to a 1963 A/H Sprite (white w/black top just like my new Roadster) which I autocrossed. I have had various other sporty cars through the years and 90+% of my daily drivers have been manuals. I always downshift but not always sequentially through all the gears (sometimes 4 to 2 for example). Downshifting properly is fun for me. Why the heck would I need to know how to heel & toe if I didn't downshift? I didn't buy a MINI to save the clutch and miss out on one of the pleasures of driving.

 

hi jhull413

my first car was a 1966 fiat 1100D with 4 on the column

i think that we are both members of a rather small club

mine cost $35, complete with 4 new cooper tires and a new sears battery, the insurance cost me $75/year, more than double what i paid for the car

my reverse was located next to 4th gear (forward and down), but had a very heavy spring to push through to get to the reverse gate

as one of the first in highschool to have a car, all my friends wanted to drive my car

i would park it nose-in to a wall and anyone who could reverse it out was allowed to drive it ... very few ever found reverse

scott

 

For those interested, the industry term is "deceleration fuel cut off" or something very close to that for the technology that cuts the fuel flow when coasting in gear. May help with Google searches if you want to pursue the topic.

As to the OP question, like some others, I try to keep my MINI in a gear that keeps the RPMs in the range of 2,000 - 3,000 as I coast (in gear) to a stop. When I get down to about 10-15 mph and a stop is imminent, that is when I'll finally pop it out of gear (2nd by that point) and then use the brakes for the final stopping action.

 

I think I need a 4th option...I usually just push in the clutch and use the brakes with no shift to neutral. I simply engage 1st when stopped and leave the clutch in until I am ready to go again. The only time I leave the car in neutral is when waiting for a train to pass.
I used to rev match, but now am in the school of thought that says "why wear out expensive tranny parts instead of cheap brake pads". Changing brakes is easy, changing clutch discs and synchros are not. Not sure how much gas can be saved with fuel cut anyway because you have to blip the throttle to rev match which uses up the gas you would save.

 

I would try to minimize the amount of time that you have the clutch pedal pushed in. While you have it pushed in, you are stressing the throw-out bearing. You could end up wearing that out sooner than the disc. Rule of thumb is to only have the clutch pedal pushed in when you are actually changing gears or starting the vehicle.

 

you are using the worst possible technique ...
you will soon be replacing the throwout bearing which requires $$$$clutch/transmission removal$$$$

the throwout bearing will not standup to the use/abuse you are giving it, the only time the clutch pedal should be depressed is when the gear shifter is in motion! never stand motionless in gear with the clutch depressed

i have driven ~1,000,000 miles in cars/pickups (all but 80,000 miles with manual tranny) and ~500,000 miles on motorcycles and just replaced my first ever clutch, on my 1997 gmc sonoma p/u with 287,000 miles, the clutch material was gone, but the throwout bearing was still good, the only reason i used up the clutch in the sonoma is i ofter tow a 10,000 pound gross weight trailer, just a little over the 5,000 pounds that gmc rates the truck to tow and starting from a dead stop does abuse the clutch a little

scott

 

Thanks everyone! I think you guys actually manged to convince my girlfriend to try to switch to #3.

 

What you are saying about the throwout bearing makes sense. However, I have been driving standard for 31 years and have never had a bearing fail. I have only replaced a clutch disc once, but that was in my Subaru which has an extra 100lb of torque over stock and gets abused at autox and track days and I wasn't the first owner for the first 60k miles. Maybe I have just been lucky.

 

As its been 20+ years since I've driven a manual I have a question. Please don't laugh and pretty please don't flame, but when braking in say 5th, once your RPM's drop don't you run the risk of stalling out? I simply can't remember.

 

yes if you run it right down to a near stop. The motor is being turned over by the wheels so it won't stall. But you would not want to run it down below idle speed say 600-700 rpm becuase it will have to catchup to maintain idle when you do de-clutch. You aren't getting much engine braking below 2k rpm anyway.

 

That is exactly the reason. Brakes, among other things, are immensely better than they used to be.

If you rev-match correctly on the downshifts, there's no problem to downshifting as you slow. The extra wear on the transmission and clutch and such is completely insignificant if you can match revs decently.

But downshifting is not necessary in today's cars. And if you rev-match poorly, you will put noticeable wear on the transmission and/or clutch.

So downshifting, or staying in the higher gear until you get down to idle, or just popping out of gear altogether, work. The problem with going to neutral is if you don't actually have to stop (e.g., if you're pulling up to a light and it turns green) you will have to figure out what gear to shift into and do that. Not a big deal, but can be annoying. Or if something Very Bad starts to happen, you won't be able to accelerate out of the way until you've put the car back in gear.


Riding the clutch is usually a bad idea. In some older cars, in fact, this actually adds extra wear to the thrust surfaces on the main crankshaft bearings! I don't know the effect on the MINI engine, but I don't like sitting there with my foot pushing the pedal to the floor for any lengthy amount of time anyway.

 

Usually downshift a gear sometimes two and leave it there. It's illegal to leave your car in neutral while the car is in motion, not that they would know anyway.