Notices
2005-2014 Mustangs Discussions on the latest S197 model Mustangs from Ford.
Sponsored by:
Sponsored by:

3.73 or 3.55?

Thread Tools
 
Search this Thread
 
Old 09-04-2009, 01:01 AM
  #1  
cgm10gt
Thread Starter
 
cgm10gt's Avatar
 
Join Date: Sep 2009
Location: AR
Posts: 41
Default 3.73 or 3.55?

Just curious. I have my '10 GT on order, I opted for the 3.73 gears...and that's fine with me, but I'm wondering if perhaps I should have gone with the 3.55's?

Basically, im wondering, how do the 3.73's manage highway cruising speeds? Are your RPM's through the roof and is the engine racing all the time, or is it more normal than that?
cgm10gt is offline  
Old 09-04-2009, 06:05 AM
  #2  
mustang51js
3rd Gear Member
 
mustang51js's Avatar
 
Join Date: Aug 2009
Location: nj
Posts: 554
Default

i have 3.90 and rpms are fine, i still dont even go into 5th gear at the track,on the highway i can 75 and be around 2500 -3000 rpms so its not bad at all
mustang51js is offline  
Old 09-04-2009, 08:09 AM
  #3  
robinsonda1
2nd Gear Member
 
robinsonda1's Avatar
 
Join Date: Jun 2009
Location: Okinawa Japan
Posts: 187
Default

I have the 3.73s in my 10 GT with the 5spd and I run about 2.5k @ 80mph. The engine is so smooth and the car is so quiet you hardly even notice.
robinsonda1 is offline  
Old 09-04-2009, 08:44 AM
  #4  
Adam
4th Gear Member
 
Adam's Avatar
 
Join Date: Jun 2009
Location: Orange County, CA
Posts: 1,162
Default

The difference between 3.55 and 3.73 at freeway speed would be barely noticeable. Go 3.73 and forget about the rest!
Adam is offline  
Old 09-04-2009, 08:50 AM
  #5  
chub46
2nd Gear Member
 
chub46's Avatar
 
Join Date: Oct 2008
Location: Alabama
Posts: 232
Default

The 3.73s will work just fine. I run 70 - 80 on the highway every day to work and my RPMs are in the low 2K range. If your worried about mpg, I get about 25 to 26mpg on the highway and 22 to 23 mpg going to and from work. But there are very few street lights where I am in Alabama. Get the 3.73 and have fun.
chub46 is offline  
Old 09-04-2009, 09:01 AM
  #6  
Xcelsius
3rd Gear Member
 
Xcelsius's Avatar
 
Join Date: Jul 2009
Location: Utah
Posts: 533
Default

My car came with the 3.55 rear. I can assure you I have no shortage of fun.
Xcelsius is offline  
Old 09-04-2009, 01:01 PM
  #7  
chub46
2nd Gear Member
 
chub46's Avatar
 
Join Date: Oct 2008
Location: Alabama
Posts: 232
Default

Originally Posted by Xcelsius
My car came with the 3.55 rear. I can assure you I have no shortage of fun.
I'm not saying you can't have fun with the 3.55s. I've driven mustangs with the 3.55s and the 3.73s, I prefer the 3.73s.
chub46 is offline  
Old 09-04-2009, 01:30 PM
  #8  
OhioState87
2nd Gear Member
 
OhioState87's Avatar
 
Join Date: Sep 2007
Location: Ohio
Posts: 401
Default

Be happy you went with the 3.73's, especially if you plan on getting different wheels/tires in the future that could possibly be a taller tire for the rear.

I have 295/45/18's out back, and with the overall extra height over stock, my gearing is equivalent to 3.3x gears, even though I have 3.55's. I don't know the exact math involved in figuring that out nor do I feel like it, but I read that if I had 3.73's, my gearing would be close to ~3.55's (which I have now). 3.90's would = ~3.73. 4.10's = ~3.90. You get the picture.
OhioState87 is offline  
Old 09-04-2009, 01:50 PM
  #9  
Cusp
2nd Gear Member
 
Cusp's Avatar
 
Join Date: Jun 2009
Location: California
Posts: 277
Default

Originally Posted by Xcelsius
My car came with the 3.55 rear. I can assure you I have no shortage of fun.
The difference between 3.55 and 3.73s is about 5%.
Cusp is offline  
Old 09-04-2009, 01:56 PM
  #10  
Lv XLR8N
2nd Gear Member
 
Lv XLR8N's Avatar
 
Join Date: Aug 2009
Location: Wisconsin
Posts: 404
Default

3:73 with 19" wheels. I am happy with it as is. I myself wouldn't do 3:55's
Lv XLR8N is offline  


Quick Reply: 3.73 or 3.55?



All times are GMT -5. The time now is 10:18 PM.