Lil'John

Title states most of it. But to elaborate:
I've got an almost stock LQ4 out of a 2004 Silverado 2500HD swapped into an older Land Cruiser. It has center dump hooker headers, no cats, and an NV4500 transmission.

I am going to tune it for MPG but was curious what RPM is the "sweat" spot before starting.

I currently have it set to do 2500rpm at 70mph. Should I shoot for a lower rpm? I've got some drivetrain modifications planned in the near future so it wouldn't hurt to adjust the rpm for 70mph.

Also, is there a better cam than stock that would help with mpg?

YellowToy/A

iTrader: (1)

Not sure how you tune for fuel economy and the ECU is in closed loop control in normal driving. But 2200 would be better then 2500 RPM.

redtan

iTrader: (5)

Definitely shoot for lower rpm. If your car makes enough power to keep it going, I would shoot for under 2000 at 70...something like 17-1800.

zstripper2k

Power under the curve is going to be your best friend when economy tuning. Lunati recently released a grind PN: 60516 that is a higher lift cam with a shorter duration and has identical power curves to stock with linear gains of 50+hp/tq on an LS1. Also with fuel economy tuning, a load bearing dyno would be your best friend as you can tune for power for part throttle. Lastly dont go too big on your exhaust. The larger the diameter of pipe, u gain HP but loose tq and that is going in the opposite direction you were looking for. Dual 2.5" pipe or 2.5" to 3" y would be your best bet and use a quality y-pipe like the flowmaster collector as I have had great success with it.

Lil'John

Thanks for the replies.

Knew I forgot something. The exhaust is a single 2.25". Originally asked for 2.5" but the eternal project didn't "force" me to check size until way too late