Skip to main content ↑ ↓
Topic: prem/reg fuel switch (Read 1383 times) previous topic - next topic

prem/reg fuel switch

What is the purpose of it?
Current: 1986 Thunderbird, 105k 3.8/C5, 2 tone  Midnight Wine/Medium Taupe, wing windows, wire wheel covers.


Former: 1985 Cougar GS 115k Oxford White/Regatta Blue, 5.0, full console, 14" 8 hole aluminum T-Bird rims, Edelbrock valve covers.

prem/reg fuel switch

Reply #1 –
for manual transmission turbo cars, the premium switch activation bumps up timing and allows more boost (at least in 87-88)

prem/reg fuel switch

Reply #2 –
Auto cars also have it. Both of the 88 TC's Ive had/have were both autos swapped to 5 speeds. Otherwise BornInAFord is correct

prem/reg fuel switch

Reply #3 –
Speaking of which, they should have never even offered an auto with the turbos, but they gotta please everybody (the very stupid and lazy masses) lmao.
Current: 1986 Thunderbird, 105k 3.8/C5, 2 tone  Midnight Wine/Medium Taupe, wing windows, wire wheel covers.


Former: 1985 Cougar GS 115k Oxford White/Regatta Blue, 5.0, full console, 14" 8 hole aluminum T-Bird rims, Edelbrock valve covers.

prem/reg fuel switch

Reply #4 –
Im glad for multiple reasons they did an auto! For one a friend of mine has a condition that limits the strength in his legs, and he has driven a TC because of the auto. On top of that for spirited driving I actually like the 3.73 gears with a 5 speed. Decent fuel mileage and gets up to speed quickly without running out at 60
 

prem/reg fuel switch

Reply #5 –
When in the regular position, timing advance is roughly 3 to 4 degrees less than when in premium across the whole timing map, and the BCS will never open, limiting boost to 10 psi on a standard trans car.  The switch actually is wired through a relay (located behind the glovebox) that signals the EEC.