Chopper

The biggest MPG gain I got was after installing a Steeda timing adjuster.(+2 mpg)I advanced it untill the CEL came on and reset the light and backed the adjuster off 1 degree.I have Steeda UDP's,SB air filter,trimmed air silencer,Red Line tranny fluid,Mobile 1 engine oil,75 mm Accufab T/B and plenum,and a full Bassani exhaust.The exhaust did nothing to the MPG's.I regularly get 32.4 mpg driving to and from work,a 100 mile round trip.On a recent dyno run the car pulled 255.4 RWHP and 293.4 ft/lbs of torque.75*air temp.75% humidityand 29.96 baro.

maddash

I dont think it to be safe to advance your timing 4 or 5 degrees, which I calculate to be 14 or 15 base timing, on 87 octane. 91+ yes,but I would not do it on 87. The 4.6 will start to detonate at about 15 degrees base timing give or take a degree even with 91+. And just because you cant hear detonation does not mean it not. Unless you want a good excuse to replace the motor dont mess with the timing if you insist on running 87.

maddash

Oh and Im speaking from experience here. Back in 03 my buddy put a steeda timing adjuster on his 01 and set the timing to 14. Well about a week later we were climbing a hill in 5th and kaaboom. No moooooo driving around. We lifted the hood and seen that there TA and said what octane are you running and he said some good ol 87. So he say we got to make a mad dash to the house (hence the name maddash). Towed it the the house, unbolted the TA, got some grease and dirt to rub the crank down to see no new tool marks. Towed it to the dealership and played dumb. Fixed under warranty.