2003 Transmission and Fuel

[RockNRollLawya]

Can someone explain to me what the ‘+’ and ‘-‘ are on the right of the gear shifter, and how to use it? I can’t seem to find a straight answer and want to be sure I don’t screw something up (as I’m known to do).
Also, what grade gasoline does everyone use in their newer models?

This page contains affiliate links for which I may be compensated. As an eBay Partner, and Amazon Associate I may be compensated if you make a purchase at no cost to you.

 

[Ike]

Can someone explain to me what the ‘+’ and ‘-‘ are on the right of the gear shifter, and how to use it? I can’t seem to find a straight answer and want to be sure I don’t screw something up (as I’m known to do).
Also, what grade gasoline does everyone use in their newer models?

The ‘#’ is for upshifting by pushing the shift to the right. The’-‘ is for downshifting by pushing the shift to the left. This is for more sporty driving if you so choose.
The manual tells us to use premium gasoline

 

[biddle]

Discusion on fuel octane is here. In short, use premium. Always use the octane fuel recommended by the manufacturer unless you have a tuner that changes the computer's octane rating/mixture.

3.9 and premium fuel

This has been discussed quite a bit. With most saying they use what the manual says. But has anyone read just why the motor needs premium. Its not a large displacement or producing that much horsepower (250). There are numerous makes producing that kind of hp out of V6's and still...

forums.fordthunderbirdforum.com

 

[The Flash]

The transmission shift lever has a gate in it. When in the D 5 position you can move the lever to the right Passenger side. That allows the transmission to only shift manually.
Manual shift mode With the gearshift lever in D5 (Overdrive), the gearshift lever can be moved to the right and into the manual shift mode. The transmission will remain in the manual shift mode until the gearshift lever is moved back to D5 (Overdrive). + and - position operation These positions allow the driver to manually select the appropriate upshift (+) or downshift (-) and gear range. • Can only be entered from the D5 position. • Gear ranges 1–5 provide the same function and ratio as found in the D5 or D4 automatic mode positions. • Transmission will not upshift or downshift unless the selector lever is moved forward or rearward. • One tap forward (+) will command the transmission to upshift one gear range. • One tap rearward (-) will command the transmission to downshift one gear range. • Upshifts are allowed at any vehicle speed, with the exception of 4th and 5th gear. The transmission will not do a 4th or 5th gear start. Ensure that the transmission is returned to 1st gear once the vehicle is stopped. If this is not done, and the transmission is in 2nd or 3rd gear, the vehicle will remain in that gear. However, if the transmission is in 4th or 5th gear, the transmission will automatically return to 1st gear. • When downshifting at normal road speeds, the transmission will only allow a downshift into the next lower gear.

Owners Manuals- https://forums.fordthunderbirdforum.com/threads/thunderbird-manuals-electronic-version.2998/