How bad do you want to get better mileage???

[pasadena_commut]

Ok, here's a thought for you guys that advocate coasting in neutral (5 speed).
What kidn of life do you expect to get out of your clutch?.

Shifting out of gear and into neutral should not cause significant wear on the clutch since at release the two sides are moving at exactly the same speed.

Shifting back into gear will wear the clutch varying amounts depending on how well the driver matches the motor speed to the transmission speed. Clearly if the driver coasts and lets the motor's RPMs drop to idle and then just pops the clutch that will cause a lot of wear. If the driver gives the motor a bit of gas first to match the RPMs fairly well, wear should be minimal.

It was always my impression that most of the wear on the clutch was coming from starting the car from a dead stop, where there was no choice but to let the clutch out slowly and let the drag inside the clutch pull the transmission up to speed. This is one reason why you go through a lot of clutches if you live in a hilly city. Once the car is moving you can shift between gears without using the clutch at all if you're very careful about matching RPMs and the synch in the transmission is pretty good. Not that the transmission should be subjected to that kind of treatment, my point is that if the car is driven properly the clutch isn't doing all that much when shifting between gears once the car is moving.

 

[maxek]

You do not have to coast at all to get exellent milage. Just keep your rpm below 2500. Try it for 100 miles and you will be suprised.

 

[fishdonotbounce]

I actually got about 150 MPG the other day. What I did was cut a giant hole below the driver's seat, removed the seat, and Fred Flinstone'd that s***. lol. It's pretty simple though guys.

Drive normally and a little bit slower at times = better MPG

Drive like a bat out of hell = piss poor MPG

 

[Sveivo]

Shifting out of gear and into neutral should not cause significant wear on the clutch since at release the two sides are moving at exactly the same speed.

Shifting back into gear will wear the clutch varying amounts depending on how well the driver matches the motor speed to the transmission speed. Clearly if the driver coasts and lets the motor's RPMs drop to idle and then just pops the clutch that will cause a lot of wear. If the driver gives the motor a bit of gas first to match the RPMs fairly well, wear should be minimal.

It was always my impression that most of the wear on the clutch was coming from starting the car from a dead stop, where there was no choice but to let the clutch out slowly and let the drag inside the clutch pull the transmission up to speed. This is one reason why you go through a lot of clutches if you live in a hilly city. Once the car is moving you can shift between gears without using the clutch at all if you're very careful about matching RPMs and the synch in the transmission is pretty good. Not that the transmission should be subjected to that kind of treatment, my point is that if the car is driven properly the clutch isn't doing all that much when shifting between gears once the car is moving.

I think the word you're looking for is rev-matching Personally, I always rev-match. I even learned the mad tight heel-and-toe not too long ago.

And actually I think that it is not worth to try to save the clutch by shifting without it. The metal parts are quite a bit more costly than the clutch, and the clutch itself lasts a long time anyways.

Ok, here's a thought for you guys that advocate coasting in neutral (5 speed).
What kidn of life do you expect to get out of your clutch?
Lets face it - a clutch is wear-device, and will only operate a miximum number of times before it begins to fail. Of ocurse, the way you shift affects this max number, but it is there.
Lets say you can get 100,00 clutch grab/releases before it begins to slip.
if you are constantly shifting into neutral to coast, you will greatly increase the rate at which you approach this number... lets say one in 5 shifts is into neutral - you have decreased the life of your clucth by 20%. Now compare the cost of replacing that thing to teh 5% gas savings. In $$, not worth it IMO!

Now the other option is to just hold in the clutch and gcoast in gear but w/o the motor "connected". People say this will wear out the pilot bearing, but after watching the mechanics of a clutch engaging/disengaging/holding open, I canno tfor teh life of me see how just holding it open longer make any difference on the bearing.

I see what you are saying, and I must say that holding the clutch pedal in while costing is not a good practice.

BUT... the slipping of the clutch you are talking about is really insignificant (assuming you are not shifting in too low a gear, in which case any debate of fuel saving techniques does not make sense anyways).

A clutch can take a lot of wear. What you are referring to is very very minor, in my experience. But to avoid this, try rev-matching.

 

[MSP-BCH]

i have a MSP and when i wife drove it for a week CITY she got 490 on a full tank. she said she shifted at 2K and never got into boost but twice..BUT when i drove it before that i could barely get 280 a full tank LMAO.
but i get 400-450 now shifting between 2-2.5K staying at 65 or less

 

[red95_240sx]

(alright)

 

[fishdonotbounce]

LMAO you douche bag. You would bring that into the conversation...

 

[MAZDA_SPEED]

Ok, here's a thought for you guys that advocate coasting in neutral (5 speed).
What kidn of life do you expect to get out of your clutch?
Lets face it - a clutch is wear-device, and will only operate a miximum number of times before it begins to fail. Of ocurse, the way you shift affects this max number, but it is there.
Lets say you can get 100,00 clutch grab/releases before it begins to slip.
if you are constantly shifting into neutral to coast, you will greatly increase the rate at which you approach this number... lets say one in 5 shifts is into neutral - you have decreased the life of your clucth by 20%. Now compare the cost of replacing that thing to teh 5% gas savings. In $$, not worth it IMO!

Now the other option is to just hold in the clutch and gcoast in gear but w/o the motor "connected". People say this will wear out the pilot bearing, but after watching the mechanics of a clutch engaging/disengaging/holding open, I canno tfor teh life of me see how just holding it open longer make any difference on the bearing.

nah dude, these clutch last up to 150k, plus my father beats, i mean beat on his 2003 protege all the way to redline. his clutch still caught like new after 40k miles+, clutches aren't changed as often as you think. if you know how to drive, clutches can last a long time.

 

[red95_240sx]

LMAO you douche bag. You would bring that into the conversation...

tahah i hope i no one brings any discussion on it.

nah dude, these clutch last up to 150k, plus my father beats, i mean beat on his 2003 protege all the way to redline. his clutch still caught like new after 40k miles+, clutches aren't changed as often as you think. if you know how to drive, clutches can last a long time.

FATHER beating on a PROTEGEE???

 

[ncbenr]

Simple way to lower RPMs...and increased gas mileage
Slap on some 185/75R16s on your car. Will drop highway RPM about 400-450 RPM.
Yes your speedo will be off.
Yes your car will be even more of a dog off the line.

 

[mp3-79bronco]

ive heard adding 2 ounces of acetone per 10 gallons gives better mpg by helping it atomize better?

also ive got a steady 23 mpg from my mp3 ever since i got it and i dont even drive that bad..i shift before 3k....then i read that the wagons are getting like 30 + s***....

 

[Azaizai]

so how about a cruise vs non-cruise comparo?

I tend to keep my manual p5 @ 65mph (3000 rpms) the entire trek. I shift around 2500 to 3000, depending on the urgency for speed while merging. I live in relatively hilly Mid-Missouri. Now I wonder if I should nix the cruise so I can let the car coast downhill (atm it seems like it compression brakes downhill to maintain the 65mph...whereas I would let it gain a lil speed...and then tends to fall behind going uphill and accelerates (sometimes to 70 before it realizes its gone past its target number)).

Think that'd make a big deal. I've been getting a consistant 35mpg on primarily *all* highway miles.

 

[323]

ive heard adding 2 ounces of acetone per 10 gallons gives better mpg by helping it atomize better?

also ive got a steady 23 mpg from my mp3 ever since i got it and i dont even drive that bad..i shift before 3k....then i read that the wagons are getting like 30 + s***....

me 2. i get 26mpg in my mp3 and i shift @ 3k -shrugs-

 

[mp3-79bronco]

and im about to go turbo too so ......damn ill be driving a 4 cylinder with the gas mileage of an 8

 

[323]

haha if you stay out of boost i think a turbo helps ur gas mileage

 

[mp3-79bronco]

sweet...nice looking car btw

 

[323]

thank ya

 

[red95_240sx]

dat avatar is what really grabs attention

 

[RatLabGuy]

I see what you are saying, and I must say that holding the clutch pedal in while costing is not a good practice.

Ah, but can you please explain WHY it is not good practice?
I am failing to see, mechanically, what will cause a problem.

Now please keep in mind also what I'm referring to is NOT popping it in and holding it just to coast (so you are using the pedal/clutch more often), but rather simply holding it in longeri n cases where you need to shift anyway.
E.g., coming downhill, stop ahead. You will have to downshift anyway, just pop it in early and coast up to the stop. Ot, holding it in longer between gears.

 

[pasadena_commut]

so how about a cruise vs non-cruise comparo?

I tend to keep my manual p5 @ 65mph (3000 rpms) the entire trek. I shift around 2500 to 3000, depending on the urgency for speed while merging. I live in relatively hilly Mid-Missouri. Now I wonder if I should nix the cruise so I can let the car coast downhill (atm it seems like it compression brakes downhill to maintain the 65mph...whereas I would let it gain a lil speed...and then tends to fall behind going uphill and accelerates (sometimes to 70 before it realizes its gone past its target number)).

Think that'd make a big deal. I've been getting a consistant 35mpg on primarily *all* highway miles.

On the flat cruise control gives the best gas mileage on the highway. I suspect that its mostly because the driver adjusts speed by nudging the cruise control up and down and doesn't touch the brakes.

However, on hills, cruise control is not a great idea. If I remember correctly the owner's manual says as much, although maybe I read that for a different car. On the hills cruise control tends to pick the wrong gear, especially going up hill, so that it shifts a bit erratically and the RPMs go up and down. For the best mpg in the hills you do not want engine or any other kind of braking going down the hills. Its just like a high school physics experiment, you want the marble to roll freely down the first hill and then use that kinetic energy to get back up the second. The laws of physics say one thing, but the laws of the highway patrol say another - if you convert all the PE to KE on a long hill the car could easily be going 110 or 120 mph (wherever wind drag equals the pull from gravity). The cops will not be amused.

If you are already getting 35 mpg I would just keep doing what you have been doing. You are unlikely to see much improvement on that.