What should I get, 3.55 or 3.73 gears? Primary concerns with the 3.73's are gas mileage and what kind of RPM's will I be pulling at 75mph if I have 17 inch rims? I already know how quick the 3.73's get up there, my buddy has them, but I was curious if this is going to be a toll on my engine and if it is going to effect my gas mileage SIGNIFICANTLY.
3.55 vs. 3.73 Gears
- Thread starter 95Doug5.0
- Start date
-
Sponsors (?)
pleasehelp
New Member
Those graphs show RPM versus speed which is a little deceptive. The difference in RPM at a 75 is about 200 RPM if memory serves me correctly.
I can't comment about gas mileage. My gears were installed around last October and I haven't put 500 miles on my car since then.
Joe
I can't comment about gas mileage. My gears were installed around last October and I haven't put 500 miles on my car since then.
Joe
You shouldn't compare the stock versus 3.73. There is no basis for comparison. Compare the speed @ 3000 RPM in 5th gear between the 3.55 and 3.73. It's a 5 MPH difference. Unless your car traps 135+ or you like to drive 120 MPH all the time, I don't see the reason for not getting a 3.73.chefster said:
The new GT needs another another full turn, too. People complain of them being gutless because they don't have enough gear.chefster said:
Joe
stangboy
Founding Member
3.55s aren't enough gear for our heavy ass cars unless you have a power-adder. I love my 3.73s. They won't make a significant difference in gas mileage.
FastGT94
New Member
I'd go 4.10's I wish I had with my 3.73's. My gas mileage went UP by 1-2 mpg on both highway and in town. I was getting 14-15 mpg in town and after the 3.73's I was getting 16-17 on a regular basis. Yes my car was daily driven at that time.
FastGT94
New Member
gcomfx.com
Founding Member
The difference in rpm's at highway speed between them is less than 150 rpm if I remember correctly. I use 373's and some times I wish I went with 410's.
You can use this to separate opinions from facts.
http://www.allfordmustangs.com/Detailed/608.shtml
Later
Grady
You can use this to separate opinions from facts.
http://www.allfordmustangs.com/Detailed/608.shtml
Later
Grady
First gear is useless in a Mustang unless you have 2.73 gears. They simply make too much torque, and combine that with a 3.35 first gear and you've got a whole bunch of tire smoke. I can make any car have "no first gear" if I tried hard enough.
My Dad let me drive his old 68 Fastback to Prom when I was in highschool. With a worked HiPo 289, a top loader 4-speed, and a 4.56 gear, that car wouldn't get traction unless you were going 25 MPH in 4th gear.
Joe
My Dad let me drive his old 68 Fastback to Prom when I was in highschool. With a worked HiPo 289, a top loader 4-speed, and a 4.56 gear, that car wouldn't get traction unless you were going 25 MPH in 4th gear.
Joe
Similar threads
