('93-'01) Double-Clutching, Rev-Matching, and Gas Mileage?

TimStevens · 05-11-2001, 07:02 AM

In the quest for better gas mileage, I've had pretty good results using the "Drive like a gramma" method (in which I visualize there's a raw egg underneath my right foot, and if I push too hard I'll break it), but I haven't been able to get any sort of steady mileage readings because at least once a week I go out and have some fun on some back roads, and I usually wind up burning 1/8th of a tank of gas in 15 miles or so.

But, that's not why I'm posting. I'm pretty religious about double-clutching and matching revs when I downshift. It was something I picked up on my MR2 with shot synchros, and I hope that continuing to do so in my WRX will preserve the tranny for an extra few miles. But I've got to thinking: how much does all that extra throttle blipping affect my mileage? I was wondering if anyone had some ideas on the subject? I don't down-shift all too often (only when I need a lower gear, not when I'm coming to a stop-sign or the like), but I'm thinking it must have some affect, especially given the heft of the stock flywheel.

Any theories?

-tim

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kyledooley · 05-11-2001, 09:02 AM

I think that once I learned to heel and toe downshift really well with my RS that my mileage seemed to drop.

Just coincidence, I think, but worth considering.

K.

tmat3 · 05-11-2001, 09:05 AM

I would say it's insignificant. I double-clutch all the time, and my mileage has stayed the same between non-double clutch days and double clutch days.

I know you were talking about your gas mileage not being so great at the meet, but I would think that it will get better as you break-in your car more. Also, consider making the car lighter somehow (i.e. get rid of backseats, use lighter wheels).

TimStevens · 05-11-2001, 09:47 AM

tmat, I'm always bitching about my mileage, and my job, and my pay...

I'm hoping things improve soon when I get some more miles on the car, and I've heard that switching to synthetic will help a bit (plan on doing that at my second oil change). Unfortunately, I can't find any light wheels that are good looking and cheap, not to mention durable...

-tim

Sean · 05-11-2001, 10:09 AM

I doubleclutch and revmatch 100%. Here is my full fuel log from when I bought the car. You'll see that the first 5000 miles has really good mileage where I was babying the car. After that, I let loose on her. You'll see the mileage go down.

http://www.trunkmonkey.com/maintenancelogtemp.cphp

<IMG SRC="http://www.trunkmonkey.com/pics/lil.gif" border=0> Fear the Trunkmonkey. There is no cone.
http://www.trunkmonkey.com/ | sean@trunkmonkey.com
Automotive Reviews by Sean | What is a Trunkmonkey?

05-11-2001, 07:02 AM	#1
TimStevens Scooby Specialist Member#: 4817 Join Date: Mar 2001 Chapter/Region: NESIC Location: Albanyish, NY Vehicle: 2012 STI, '02 WRX '91 MR2, '05 Speed Triple	Double-Clutching, Rev-Matching, and Gas Mileage? In the quest for better gas mileage, I've had pretty good results using the "Drive like a gramma" method (in which I visualize there's a raw egg underneath my right foot, and if I push too hard I'll break it), but I haven't been able to get any sort of steady mileage readings because at least once a week I go out and have some fun on some back roads, and I usually wind up burning 1/8th of a tank of gas in 15 miles or so. But, that's not why I'm posting. I'm pretty religious about double-clutching and matching revs when I downshift. It was something I picked up on my MR2 with shot synchros, and I hope that continuing to do so in my WRX will preserve the tranny for an extra few miles. But I've got to thinking: how much does all that extra throttle blipping affect my mileage? I was wondering if anyone had some ideas on the subject? I don't down-shift all too often (only when I need a lower gear, not when I'm coming to a stop-sign or the like), but I'm thinking it must have some affect, especially given the heft of the stock flywheel. Any theories? -tim * Registered users of the site do not see these ads.

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05-11-2001, 09:02 AM	#2
kyledooley Scooby Specialist Member#: 1055 Join Date: Mar 2000 Chapter/Region: MWSOC Location: Romeoville, IL Vehicle: 2005 No legacy for u It's a diesel	I think that once I learned to heel and toe downshift really well with my RS that my mileage seemed to drop. Just coincidence, I think, but worth considering. K.

05-11-2001, 09:05 AM	#3
tmat3 Scooby Specialist Member#: 2817 Join Date: Nov 2000 Location: NYC and Troy, NY Vehicle: 2001 Impreza 2.5RS BRP	I would say it's insignificant. I double-clutch all the time, and my mileage has stayed the same between non-double clutch days and double clutch days. I know you were talking about your gas mileage not being so great at the meet, but I would think that it will get better as you break-in your car more. Also, consider making the car lighter somehow (i.e. get rid of backseats, use lighter wheels).

05-11-2001, 09:47 AM	#4
TimStevens Scooby Specialist Member#: 4817 Join Date: Mar 2001 Chapter/Region: NESIC Location: Albanyish, NY Vehicle: 2012 STI, '02 WRX '91 MR2, '05 Speed Triple	tmat, I'm always bitching about my mileage, and my job, and my pay... I'm hoping things improve soon when I get some more miles on the car, and I've heard that switching to synthetic will help a bit (plan on doing that at my second oil change). Unfortunately, I can't find any light wheels that are good looking and cheap, not to mention durable... -tim

05-11-2001, 10:09 AM	#5
Sean Scooby Guru Member#: 518 Join Date: Nov 1999 Chapter/Region: NESIC Location: Trunkmonkey Racing Vehicle: 762 PGT Impreza L, Silverado EXT, Yaris	I doubleclutch and revmatch 100%. Here is my full fuel log from when I bought the car. You'll see that the first 5000 miles has really good mileage where I was babying the car. After that, I let loose on her. You'll see the mileage go down. http://www.trunkmonkey.com/maintenancelogtemp.cphp <IMG SRC="http://www.trunkmonkey.com/pics/lil.gif" border=0> Fear the Trunkmonkey. There is no cone. http://www.trunkmonkey.com/ \| sean@trunkmonkey.com Automotive Reviews by Sean \| What is a Trunkmonkey?