Will 3.73's kill my mileage?

5spd GT

"the 5.0 owns all"

Founding Member

Aug 7, 2002

9,516

6

99

Arkansas

Jul 1, 2005

#21

• Jul 1, 2005

• #21

It is a white 23 tooth speedo gear for 373's. Closest they make to match internal tranny gear...

I was getting 18-20mpg before my h/c/i with my 373's. Added the h/c/i and got up to 24mpg... average 21-22mpg.

 

GRGT1994

New Member

Sep 22, 2004

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0

Jul 2, 2005

#22

• Jul 2, 2005

• #22

You can also use a Speed Cal (50Resto and Brothers Performance). Its a $100 item, but it dials you right in, especially if you go 4.10.

Otherwise, the 23 tooth would get you within 3.5 miles per hour of dead on.

 

89MustangGX

I have nothing productive to add!

Jul 3, 2001

10,262

1

0

Mill Creek, WA

Jul 2, 2005

#23

• Jul 2, 2005

• #23

I never saw upper 20's in mileage before, but I did see low 20's -- which was higher after the gear swap.

 

G

grrrrrrr

New Member

May 20, 2003

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norfolk, VA

Jul 2, 2005

#24

• Jul 2, 2005

• #24

I have the speedo correction gear as well, I got 240 miles to my last tank, which is unheard of for me, before the gear swap I was getting anywhere from 160 - 200 miles a tank. Now 220 is the norm...

 

Venom351R

Founding Member

Apr 27, 2002

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98

MAINE

Jul 2, 2005

#25

• Jul 2, 2005

• #25

Swarzkopf said:

The only way to really increase performance and not effect gas mileage is nitrous.

Click to expand...

I increased performance and got better gas mileage after my dyno tune/chip.

 

DFG 5OH

Active Member

Aug 28, 2004

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36

Louisville, KY

Jul 2, 2005

#26

• Jul 2, 2005

• #26

Well on a stock engine, with exhaust, and shifter, i get 17 in the city, and 25 on the highway. I hope its better once i get my H/C/I.

You guys with built engines, and gears getting better milage than me is really blowing my mind.

 

Joe 5.0

Founding Member

Feb 1, 2002

1,184

2

38

Macomb, MI (metro detroit)

Jul 5, 2005

#27

• Jul 5, 2005

• #27

My city mpg improved with the gears, I believe mostly because the engine didnt have to lug off the line, it is much more effortless to get moving. Of course if you floor it all the time its gonna kill mileage, but if you drive nice you can still pull low 20's combined even with aggressive driving.

On the expressway I never drive less than 75mph, but I use cruise control whenever possible. I find it helps mileage because it cuts down on uneccesary throttle inputs.

I get 19-21mpg combined on average, but if I drive with efficiency in mind I can get 23-24mpg combined and 300+miles per tank. This past weekend I drove 200 miles straight on the expressway, all cruise control set at 75-85mph. Got 325miles to that tank and averaged 25mpg. That was even with a decent amount of semi aggressive passing.

 

DFG 5OH

Active Member

Aug 28, 2004

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Louisville, KY

Jul 5, 2005

#28

• Jul 5, 2005

• #28

thats pretty good

 

G

grrrrrrr

New Member

May 20, 2003

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norfolk, VA

Jul 5, 2005

#29

• Jul 5, 2005

• #29

uneccesary throttle inputs

Click to expand...

All throttle inputs are neccesary and just and therefore beneficial for the people.

 

HGFireHazard

Member

Apr 10, 2005

460

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17

Michigan

Jul 6, 2005

#30

• Jul 6, 2005

• #30

My dad put 373's in his '88 GT and I believe he got a 21 1/2 tooth red gear from a Ford dealership here in Michigan. I'm not entirely sure so I'll ask him when he comes home from work today, but I think it's almost 100% accurate... but don't quote me yet.

 

a_k

New Member

Nov 12, 2004

170

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Saratoga NY

Jul 6, 2005

#31

• Jul 6, 2005

• #31

I need to get some 3.73's in by the end of the month I have decided. NOt trying to change a topic here but with so many people answering with them already, when you got them installed did you get all new bearings and everything. One shop told me to do it right and replace everything while he is back there im looking at upwards of $1000. Im going to start looking around for better prices but thanks for the help.

Adam

 

Pokageek

Active Member

Jun 10, 2005

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MA, USA

Jul 6, 2005

#32

• Jul 6, 2005

• #32

$500 is a fair price. $1000 is robbery.

 

94-302-vert

Active Member

Aug 16, 2004

1,947

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36

NE CT

Jul 6, 2005

#33

• Jul 6, 2005

• #33

There is a guy that advertises in the bargainnews taht says all parts included, $695 (i think) for gears, trac-loc rebuild and all new bearings and seals... I vote to do it all at once... well I ended up doing all new bearings etc after I had my pinion bearing get wiped shortly after the gear install...

 

CManT1914

New Member

Feb 5, 2004

3,172

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Killeen, Texas

Jul 6, 2005

#34

• Jul 6, 2005

• #34

a_k said:

I need to get some 3.73's in by the end of the month I have decided. NOt trying to change a topic here but with so many people answering with them already, when you got them installed did you get all new bearings and everything. One shop told me to do it right and replace everything while he is back there im looking at upwards of $1000. Im going to start looking around for better prices but thanks for the help.

Adam

Click to expand...

You butt should hurt if you pay $1000 for gears. Here's what everything typically costs:

Gears: $150
Install kit: $50
Labor: $200-$300

You shouldn't have to pay more than $400 - $500 for everything.

 

TripleBlack95

Member

Dec 14, 2003

153

1

16

Burke (Fairfax), VA

Jul 6, 2005

#35

• Jul 6, 2005

• #35

So I'm guessing I should go with 3.73's over 3.55's? This thread pretty much answers my concerns for gas mileage. Thanks guys.

 

CManT1914

New Member

Feb 5, 2004

3,172

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0

Killeen, Texas

Jul 6, 2005

#36

• Jul 6, 2005

• #36

TripleBlack95 said:

So I'm guessing I should go with 3.73's over 3.55's? This thread pretty much answers my concerns for gas mileage. Thanks guys.

Click to expand...

Yes