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  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-

Transmission Upgrade, Miles per Gallon, and Future Plans

  • Thread starter Thread starter bretamo
  • Start date Start date Nov 10, 2007

bretamo

Member
May 13, 2005
122
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Nov 10, 2007
#1
  • Nov 10, 2007
  • #1
I have committed to installing a quality turbo kit next year, which will allow my stock-like set up to maximize street performance and miles-per-gallon. With the stock CAM I look to have a daily driver that has decent gas mileage, but can get a boost to 450hp when I need it.

That given, I am wondering if the T-56 6-speed transmission would be a good addition.

I drive about 100 miles a day, with about half of that on the hghway either in 4th gear (45-55mph) or in 5th (65-75mph).

The T-56 has gear ratios of 2.97 2.07 1.43 1.00 .80 .62, and I am curious about that ".80" 5th gear. I am wondering if the T-56's 5th gear would give me a bit of a break on gas mileage when I steadily drive in that 45-55mph range?

I do have some concerns. What would the T-56 do to my stop-light-to-stop light driving (the 2.97 gear 1st gear), and will my speedometer be accurate?

I'd appreciate a comment or two from anyone who installed the T-56 in their near stock-like Mustang.

Thanks in advance.
 

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
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Massachusetts
Nov 10, 2007
#2
  • Nov 10, 2007
  • #2
A set of steep gears will cure that low 1st gear. Use some 3.73's or 4.10's and you won't have a problem but you will need to use 6th to keep a low OD. Then again you may have the HP levels needed to push the t-56. A lot of guys who have issues with the steep gearing don't have the 400HP/400TQ that the trans was geared around.

I don't know about gas milage though. Honestly a 450HP 5.0 Mustang isn't exactly going to sip gas. A lot of claims of good mileage (~25MPG) come from guys who do strictly highway driving in the highest gear...which sounds like your situation. Once they get around town and start shifting it goes right down to nothing.
 
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