down shifting and not coasting - Page 2 - Toyota Yaris Forums

pennystocks · 06-11-2006, 01:42 AM

Bad news, the yaris doesn't "en-lean" when engine breaking. All the GMs i'v owned you could really feel it kick the fuel flow down when engine breaking. My aurora you could see then MPG increase when engine breaking, it auctually got less MPG when in neutral vs drive for coasting.

My scan gauge shows 0.2 Gallons Per Hour when costing in neutral for the Yaris. I did some engine breaking in 2nd and it was around 0.5 GPH. Also when you feel that slight engine break when coasting (you can slightly feel it kick in and out on my auto) is putting the PCM into open loop for a couple of seconds and the GPH is the same as in neutral. Also coasting it reads about 200-250 MPG and when downshifting it drops to 60-100.

I dont think there's a need for the yaris to enlean tho. I just did a trouble code test on a chicks car at work and her 2000 or so neon 4 banger showed 0.6 GPH at idle. I cant imagine what my aurora was at at idle. So thats round 5 hours for the car to idle out a gallon of gas. and 2 days to idle out a tank, not too shabby :)

So coasting in neutral is the best way in the yaris for MPG. BTW full throttle is around 6-7 GPH and normal driving is 1-3 ish and idle w/ the AC on is 0.3 and auctually shutting the car off while long coasting can add 1 or 2 MPG as long as its done on a normal basis. I have an auto so it kinda sucks to crank the starter 50 times a day. Just think of them as free miles that dotn cost you $$$ :)

stuffy · 06-11-2006, 02:07 PM

i've been driving manual since i got my license about 16 years ago, and i have always downshifted when coming to a stop, and i have only replaced a clutch once,but what i would like to know...

...what the hell is rev-matching? i've never heard that term before (car illiterate to some degree),
does this mean that as you slow down you just continue to drop it into the appropriate gear so the engine rev doesn't increase?

pennystocks · 06-11-2006, 06:02 PM

rev matching w/o using the clutch Lets say in 2nd gear at 20 mpg your at 3k rpm. You can put it into 2nd gear w/o the clutch by reving the enigne to 3k rpm while in neutral and off the clutch. Dont try it at that speed or rpm, i dont knwo the rpm spots of the yaris stick but its less wear on the clutch if you can get used to double clutching. If you do it wrong it wont go in or it'll grind.

Double clutching is for less wear on teh syncros (the things that make it so the gears dont grind). Lets say your in 5th at 40 mph. If you stick it in 1st its gonna fight for a second to go in w/ the clutch down, those are the syncros spinning up the trans part of the clutch to match the required engine rpm. To double clutch, pop it in neutral off the clutch, rev the engine to 5-6k rpm, then real quick hit the clutch and pop it in 1st, should go in smoothly.

Basically you want to rev the engine to where you think it should be when putting it in a gear and you must be off the clutch and in neutral to spin up the trans.

echo_hrs · 06-11-2006, 07:08 PM

The whole reason synchromeshes were invented for manual transmissions was to eliminate the need to double clutch...However it can save wear on the synchros if you are driving in a manner (aggressive) that puts heavy wear on them...I have driven previous cars in my youth being hard on the clutch, and all I can say, is that I still got 200k kms out of those original clutches with 1st and 2nd gear tire spinning etc...

Cheers

stuffy · 06-11-2006, 07:23 PM

thanks for the info guys, i would like to try that sometime, maybe i should go to driving school to learn.....

ricko · 06-12-2006, 12:41 PM

Quote:

Originally Posted by stuffy

thanks for the info guys, i would like to try that sometime, maybe i should go to driving school to learn.....

If you want to have some real fun while learning, try the race driving school at Shannonville (aka Nelson International Speedway). They have different programs at different pricepoints, covering everything from defensive driving techniques, to actual learn to race days. I've done one of the motorcycle race days, and it was first class!!!

Fat Felixxx · 06-11-2006, 09:21 PM

In my experience, the general rule of thumb is to use brakes as the primary way of slowing the car down. I heel-toe all the time, but I almost always have the brakes doing A LOT more work than the engine is.

The clutch will not experience any abnormal wear and tear when downshifting correctly(via rev-matching), but it is the tranny that is taking the load when engine braking.

Bottom line, what's more expensive to replace? Brake pads and rotors or a transmission?

Leenis24 · 06-11-2006, 11:06 PM

I just put the clutch in and coast using brake to come to a complete stop. I see it being pointless to keep downshifting through every gear until you stop, its just not necessary, and wears your clutch more. I dont care how good you rev match, your still using your clutch more. And to me, more clutch usage means it wears faster.

Fat Felixxx · 06-12-2006, 04:01 AM

Quote:

Originally Posted by Leenis24

I just put the clutch in and coast using brake to come to a complete stop. I see it being pointless to keep downshifting through every gear until you stop, its just not necessary, and wears your clutch more. I dont care how good you rev match, your still using your clutch more. And to me, more clutch usage means it wears faster.

Keeping the clutch depressed for long periods of time also wears out the clutch quicker.

boxerboy · 06-12-2006, 06:17 AM

With proper driving you should not need worry about the trans. You will go threw many brake jobs first.

Uglyboyed · 06-12-2006, 11:06 AM

i usually downshift if im in a rush. most of the time i coast so i can give my car a lil break from the damage i do to its engine when i driving.

pennystocks · 06-12-2006, 12:32 PM

Quote:

However it can save wear on the synchros if you are driving in a manner (aggressive) that puts heavy wear on them

Yea i'm speaking from experience with a '97 6-speed Trans Am 5.7 liter tho

But if can get good at shifting w/o a clutch it puts less wear on the clutch which will need to be replaced in the future reguardless of how you drive it.

Quote:

and i have only replaced a clutch once

I'v replaced on my TA, ahem:
clutch
throwout bearing (a 30 mile drive w/o a clutch really sucks :)
stock gears once
4.11 gears twice
transmission once

Fun but sometimes not worh the money
BTW she ran low 13's in the 1/4 mile (or 400 meter) and a top speed of 160 mph (or 260 kph), talk about a rush =D

stuffy · 06-12-2006, 08:23 PM

thanks for the info ricko, i am definitely interested in taking a class or two!

pennystocks · 06-13-2006, 12:47 AM

If you have ABS then pop it in neutral, the ABS along side the EBD will work fine.

If you dont have ABS then keep it in gear. It will be alot harder to lock up the tires when its got resistance from the engine. If you engine does die tho make sure you quickly hit the clutch, cause the engine will keep the tires locked.

boxerboy · 06-13-2006, 06:18 AM

Thats the key smoothly. Well said.

06-11-2006, 01:42 AM	#1
pennystocks View User's Garage Drives: 07 Civic Si Coupe(Black Pearl) Join Date: May 2006 Location: Chicago, IL Posts: 159	Bad news, the yaris doesn't "en-lean" when engine breaking. All the GMs i'v owned you could really feel it kick the fuel flow down when engine breaking. My aurora you could see then MPG increase when engine breaking, it auctually got less MPG when in neutral vs drive for coasting. My scan gauge shows 0.2 Gallons Per Hour when costing in neutral for the Yaris. I did some engine breaking in 2nd and it was around 0.5 GPH. Also when you feel that slight engine break when coasting (you can slightly feel it kick in and out on my auto) is putting the PCM into open loop for a couple of seconds and the GPH is the same as in neutral. Also coasting it reads about 200-250 MPG and when downshifting it drops to 60-100. I dont think there's a need for the yaris to enlean tho. I just did a trouble code test on a chicks car at work and her 2000 or so neon 4 banger showed 0.6 GPH at idle. I cant imagine what my aurora was at at idle. So thats round 5 hours for the car to idle out a gallon of gas. and 2 days to idle out a tank, not too shabby :) So coasting in neutral is the best way in the yaris for MPG. BTW full throttle is around 6-7 GPH and normal driving is 1-3 ish and idle w/ the AC on is 0.3 and auctually shutting the car off while long coasting can add 1 or 2 MPG as long as its done on a normal basis. I have an auto so it kinda sucks to crank the starter 50 times a day. Just think of them as free miles that dotn cost you $$$ :) Last edited by pennystocks; 06-11-2006 at 01:53 AM.

06-11-2006, 09:21 PM	#7
Fat Felixxx Drives: s13 w/sr20det Join Date: Jun 2006 Location: San Dimas, CA Posts: 21	In my experience, the general rule of thumb is to use brakes as the primary way of slowing the car down. I heel-toe all the time, but I almost always have the brakes doing A LOT more work than the engine is. The clutch will not experience any abnormal wear and tear when downshifting correctly(via rev-matching), but it is the tranny that is taking the load when engine braking. Bottom line, what's more expensive to replace? Brake pads and rotors or a transmission? __________________ www.fetchgarage.com www.fetchvip.com

Thread Tools
Show Printable Version Email this Page
Display Modes
Switch to Linear Mode Hybrid Mode Switch to Threaded Mode

06-11-2006, 02:07 PM	#2
stuffy Drives: 06 yaris 5-dr le man Join Date: Mar 2006 Location: ontario, canada Posts: 699	i've been driving manual since i got my license about 16 years ago, and i have always downshifted when coming to a stop, and i have only replaced a clutch once,but what i would like to know... ...what the hell is rev-matching? i've never heard that term before (car illiterate to some degree), does this mean that as you slow down you just continue to drop it into the appropriate gear so the engine rev doesn't increase?

06-11-2006, 06:02 PM	#3
pennystocks View User's Garage Drives: 07 Civic Si Coupe(Black Pearl) Join Date: May 2006 Location: Chicago, IL Posts: 159	rev matching w/o using the clutch Lets say in 2nd gear at 20 mpg your at 3k rpm. You can put it into 2nd gear w/o the clutch by reving the enigne to 3k rpm while in neutral and off the clutch. Dont try it at that speed or rpm, i dont knwo the rpm spots of the yaris stick but its less wear on the clutch if you can get used to double clutching. If you do it wrong it wont go in or it'll grind. Double clutching is for less wear on teh syncros (the things that make it so the gears dont grind). Lets say your in 5th at 40 mph. If you stick it in 1st its gonna fight for a second to go in w/ the clutch down, those are the syncros spinning up the trans part of the clutch to match the required engine rpm. To double clutch, pop it in neutral off the clutch, rev the engine to 5-6k rpm, then real quick hit the clutch and pop it in 1st, should go in smoothly. Basically you want to rev the engine to where you think it should be when putting it in a gear and you must be off the clutch and in neutral to spin up the trans.

06-11-2006, 07:08 PM	#4
echo_hrs Around the universe... Drives: Uber-Evolved Pokemon Join Date: Jan 2006 Location: Top Gear Test Track Posts: 228	The whole reason synchromeshes were invented for manual transmissions was to eliminate the need to double clutch...However it can save wear on the synchros if you are driving in a manner (aggressive) that puts heavy wear on them...I have driven previous cars in my youth being hard on the clutch, and all I can say, is that I still got 200k kms out of those original clutches with 1st and 2nd gear tire spinning etc... Cheers

06-11-2006, 07:23 PM	#5
stuffy Drives: 06 yaris 5-dr le man Join Date: Mar 2006 Location: ontario, canada Posts: 699	thanks for the info guys, i would like to try that sometime, maybe i should go to driving school to learn.....

06-11-2006, 11:06 PM	#8
Leenis24 lil' town up north Drives: 07 Yaris LB 5 speed Meteorite Join Date: Apr 2006 Location: Northern Vermont Posts: 92	I just put the clutch in and coast using brake to come to a complete stop. I see it being pointless to keep downshifting through every gear until you stop, its just not necessary, and wears your clutch more. I dont care how good you rev match, your still using your clutch more. And to me, more clutch usage means it wears faster.

06-12-2006, 06:17 AM	#10
boxerboy Drives: WRX ,Tacoma and Yaris Join Date: Apr 2006 Location: North Carolina Posts: 206	With proper driving you should not need worry about the trans. You will go threw many brake jobs first.

06-12-2006, 11:06 AM	#11
Uglyboyed Drives: 07 Yaris Sedan S Flint Mica Join Date: May 2006 Location: Fort Lauderdale, FL Posts: 131	i usually downshift if im in a rush. most of the time i coast so i can give my car a lil break from the damage i do to its engine when i driving.

06-12-2006, 08:23 PM	#13
stuffy Drives: 06 yaris 5-dr le man Join Date: Mar 2006 Location: ontario, canada Posts: 699	thanks for the info ricko, i am definitely interested in taking a class or two!

06-13-2006, 12:47 AM	#14
pennystocks View User's Garage Drives: 07 Civic Si Coupe(Black Pearl) Join Date: May 2006 Location: Chicago, IL Posts: 159	If you have ABS then pop it in neutral, the ABS along side the EBD will work fine. If you dont have ABS then keep it in gear. It will be alot harder to lock up the tires when its got resistance from the engine. If you engine does die tho make sure you quickly hit the clutch, cause the engine will keep the tires locked.

06-13-2006, 06:18 AM	#15
boxerboy Drives: WRX ,Tacoma and Yaris Join Date: Apr 2006 Location: North Carolina Posts: 206	Thats the key smoothly. Well said.